Hemp Growing

A particular con- figuration considered in this study is upward flame spread in the flue space between corrugated cardboard, which is typical of warehouse storage arrangements. The model was extended to account for both convective and radiative heat transfer by incorporating convective and radiative heat transfer correlations. This segregated approach effectively uses a non-dimensional parameter to represent the mass transfer processes, the gas phase heat transfer by including an appropriate convective heat transfer correlation, and radiative heat transfer effects that are based on previous studies.Previous studies have attempted to model some of the large-scale effects of warehouse fires by measuring the relevant parameters using bench-scale test methods. One such effort by Hamins and McGrattan constructed single cell replicates of a Group A plastic commodity. The purpose of the Group A plastic tests was to provide input parameters into a computational fluid dynamics model using a measured heat release rate as the thermal loading input for a large-scale warehouse fire. The model predictions were unable to describe the detailed fire growth in storage applications. Several studies have addressed the issue of upward flame spread on corrugated cardboard surfaces. Grant and Drysdale modeled the flame spread along corrugated cardboard during the early growth stages of a warehouse fire by adapting the linearized Satio, Quintiere, and Williams flame spread model with Karlsson’s burnout length and solving numerically. Dimensional parameters that were obtained experimentally were used as inputs to numerically model the flame height, velocity of the flame front, and pyrolysis front progression as a two-dimensional problem. Good agreement between the experimental results and the numerical results were obtained,industrial drying racks although the model was found to be sensitive to averaged input parameters, such as the forward heat flux from the flame.

Alvares et al. studied the effects of panel separation on vertical flame spread and mass-loss rates in small-scale corrugated cardboard tests to determine the rate of fire growth along vertical flues in warehouses. Continued efforts by Ingason and de Ris and Ingason have identified the importance of the commodity configuration, the mode of heat transfer, and the flue spacing of commodity boxes in warehouse fires. Ingason’s work identified some of the dominant factors in the large-scale warehouse fire growth process, and emphasized the importance of separating the material properties of the fuel from the heat transfer and flow conditions that can result due to the various configurations of the fuel packages. Experimental correlations of rack-storage fires are available in previous literature, including heat release rates, boxed in-rack flame heights, in-rack plume temperatures, and heat fluxes. In separating the warehouse fire problem into two distinct phenomena, it then becomes a problem of defining the material properties , flow conditions , and heat transfer . Work performed by de Ris and Orloff [15], de Ris et al. [16], Foley [17], and Foley and Drysdale [18]served to characterize the mode of heat transfer from an upward propagating flame in a warehouse configuration and to quantify the convective and radiative heat transfer that drives the upward flame spread process in the gas phase. Variations in the heat transfer from the small-scale to the largescale was shown by de Ris et al. [16] to be related by similarity effects that are present in buoyant, turbulent boundary layer flows. This result can be used to extend the analytical results that were developed for heat and mass transfer in laminar boundary layers to turbulent boundary layers. In the early stages of a warehouse fire, before the fire sprinklers are activated, the mass transfer is intrinsically coupled to the material properties of the stored commodity, packing material, and outer corrugated cardboard covering. Due to the different burning behavior of each material, which is also a function of the packing and orientation, the problem of classifying a commodity based on its fire hazard is a complex one.

A general approach for describing the heat, mass, and momentum transfer by way of differential equations for simple geometries such as a droplet, flat horizontal, and vertical plate are discussed extensively in previous fire literature.As explained in a recent publication, a number of improved laminar boundary layer types of theories result in formulas that are more complicated than Eq. 3, but the results are qualitatively the same. In larger tests that were previously performed, the fluctuating flames and the incipient turbulence raise questions about the degree of applicability of such theorems. For these reasons, this simple description of the mass transfer, Eq. 3, was chosen in this study over other relevant expressions. In this study, the B-number is primarily a function of the material properties of a given fuel and it is obtained in a controlled experimental environment by assuming that the primary mode of heat transfer at the bench-scale is convection. This assumption is reasonable for the small, laminar flames observed in this study. In examining Eq. 2, the B-number can be considered to be a ratio of the available energy to the energy required to gasify a given fuel . Thus, the B-number is intrinsic to the properties of a material and is therefore independent of a particular scale. This allows for the results from the bench-scale tests to be used as a material input for the prediction of large-scale warehouse fire behavior. Figure 3 shows a schematic of the experimental setup. A total of 9 tests were conducted using two different samples: single-wall corrugated cardboard and polystyrene . The samples measured 5 cm wide by 20 cm in height. This aspect ratio was selected because laminar flames were the primary focus of the bench-scale tests due to the more controllable environment for isolating material properties and separating gas-phase phenomena, and upwardly-spreading flames typically become turbulent above 20 cm, which is accounted for in a later section when large-scale warehouse fires are considered.

For the bench-scale tests, a transition to a turbulent regime was not considered for simplicity, which agreed with visual observations. For this study, the sample width was fixed at 5 cm to minimize the amount of variance between the tests and because a smaller sample size may affect the amount of combustible gases generated by the fuel due to significant diffusion of the fuel to the sides of the sample. The typical mass of the samples was 4 g for corrugated cardboard and 36 g for polystyrene. Corrugated cardboard and polystyrene were chosen to be tested because they are the components of a Group A plastic commodity that is used to represent a worst-case fire scenario in large-scale warehouse tests. Additionally, corrugated cardboard is typically the first item to ignite and sustain flame spread in a warehouse fire. The measured quantities for each test included the mass-loss rate, flame height, and pyrolysis height. The corrugated cardboard used in these tests was identical to the con- figuration and thickness that is used to package standard Group A plastics, and of the same type used in the small-scale tests that were performed by the authors in Part I. The corrugated cardboard samples were of a type ‘C’ flute with a nominal thickness of 4 mm and 135 flutes per meter width [37] as shown in Figure 4. All of the tests were performed with the flutes aligned vertically along the 20 cm dimension,commercial greenhouse benches which is similar to the orientation of the flutes in an upright commodity box. The polystyrene samples were 3 mm thick as shown in Figure 4. The mode of ignition for the tests was a small aluminum tray measuring 5 x 0.5 x 0.5 cm that was placed at the base of the sample and contained a thin strip of glass fiber insulation soaked with n-heptane. This ensured a uniform mode of flaming ignition along the base of the fuel sample. The corrugated cardboard tests used 0.25 mL of n-heptane for ignition, whereas the polystyrene tests used 0.75 mL of n-heptane because it took a longer time for the polystyrene samples to ignite. After initial ignition of the n-heptane, the n-heptane typically burned out within 5-10 seconds and only served to ignite the fuel sample uniformly along the bottom edge. All of the fuel samples were insulated on the back and sides with 0.64 mm thick fiberboard insulation to isolate the burning to the front face of the samples only. The samples were secured in place by the insulating fiberboard sheets that were supported by four metal screws attached to the 1.9 cm thick fiberboard base .

All of the corrugated cardboard tests burned to completion and self-extinguished once the fuel was depleted. The polystyrene samples were manually extinguished after the flame reached a pyrolysis height of about 10 cm due to excessive smoke production and dripping on the bench-scale apparatus. However, the dripping and deformation of the polystyrene was not considered to be significant during the time frame considered in the results because the sample size in the experiment was small, and a significant accumulation of melted polystyrene was not observed during this time period. The mass lost by the specimen was measured continuously using a load cell with an accuracy of ± 0.5 g as specified by the manufacturer. This is approximately 12% of the nominal initial mass of the corrugated cardboard samples and 2% of the nominal initial mass of the polystyrene samples. To measure the flame heights and record the burning history of the tests, video and still images were captured using a Sony Handycam HRR-SR5 model camera and a Canon EOS-5D digital single-lens reflex camera. Figure 5 depicts a visual time history of the vertical flame spread along a corrugated cardboard sample. The images were then loaded onto a computer, and a MATLAB image processing script was used to visually determine the flame heights as a function of time from each test. The flame height was defined as the tip of an attached yellow flame and was selected visually from each picture by using the script. The processed images and resulting flame heights were consistent with visual comparisons from the test videos. Similar to the flame heights, observations of the visual charring on the corrugated cardboard was used to determine the location of the pyrolysis front. For the polystyrene samples, visual bubbling and charring from the video were used to determine the location of the pyrolysis front. The corrugated cardboard and polystyrene tests were fairly repeatable, and the heights of the pyrolysis front in the laminar regime were fairly similar; thus, a best-fit functional approximation of the pyrolysis heights was made. This approximation was later used to determine an average mass-loss rate per unit area , and finally, a B-number was calculated for each test. After the maximum pyrolysis height was reached, a constant height of 20 cm or 10 cm was assumed, which represents the entire surface of the front face of the sample. The results described in this section are based on a total of 9 bench scale tests that were performed using the two samples that were discussed in Section 3. After ignition along the base of the samples, the flame spread in the upward direction along the fuel samples. Due to edge effects along the fuel sample, a small amount of two-dimensional flame spread occurred in the experiment. As the excess pyrolyzate burned above the pyrolysis zone, the unburned fuel above the pyrolysis zone was heated to its ignition temperature and the flame spread in the upward direction at an increasing rate. As described in Section 3, the mass-loss rates were trimmed to the time period during upward flame spread along the samples. During the period of upward flame spread, the average value of ˙m00f for corrugated cardboard was within a range of 7.3 − 7.9 · 10−4 g/cm2 –s, and for polystyrene was within a range of 6.7−6.8·10−4 g/cm2 –s. Figures 6 & 6 show the flame heights that were measured in the bench-scale experiments for corrugated cardboard and polystyrene and the least-squares fit to the pyrolysis height that was used to determine the area burning, and later the average B-numbers for the corrugated cardboard and polystyrene samples. Using an average value from all of the tests that were performed on a given material sample, the B-number for corrugated cardboard was calculated to be 1.7 and for polystyrene was calculated as 1.4 .

To see how the risk characterization might change if different thresholds were selected, a comparison with the ODTC50 ranges from AIHA and the RELs from California was conducted . In the states that have legalized cannabis use medicinally and by adults, the cultivation in warehouses has led to nuisance odor complaints. The grow cycle includes a budding stage with “skunk” odor notes. Most cultivation warehouses stagger the growth cycles, so budding is an ongoing occurrence. As a best practice, exhaust ventilation is passed through an activated carbon filter; however, the efficiency is typically 50-98% , so odorous compounds are still emitted. Colorado has required odor management plans certified by an industrial hygienist to ensure best practices are implemented. In 2003, California was the first state to allow medicinal cannabis use . In 2018, cultivation for adult use became legal . Today, regions throughout the state – such as Sonoma County, Sacramento County and Greater Palm Springs – are managing the side-by-side growth of the indoor-cultivation industry and nearby residences. The first study to report Odor Activity Values for odorants emitted from cannabis identified a list of over 20 substances, which were different than those traditionally associated with cannabis odor . OAVs could only be calculated for those odorants that had existing ODTC50 values in the literature. Samples were not living cannabis plants, but rather fresh, old and desiccated cannabis, and some monitoring was outside storage bags to simulate a person being pulled over by police while transporting cannabis. The most odorous compounds based on OAVs are listed in Table 4.8 and provide a starting point for future odor research.

There are substantial uncertainties in the risk assessment of odorants,greenhouse bench top the greatest being how likely it is that the individual odorants monitored actually are the main contributors to the overall odor sensed. Missing the key odorants invalidates the study. OPM can help identify key odorants that have been compiled into odor wheels . The exposure measurements tend to have less uncertainty than the thresholds against which they are evaluated. ODTC50 values typically range over several orders of magnitude, and the health hazard thresholds incorporate one-to-three orders of magnitude of uncertainty factors in their extrapolation from animal data. Even under controlled conditions using test odorants, panelist threshold testing by dilutions resulted in inter laboratory variation in results up to 4-fold . Accordingly, most risk characterizations are crude, screening-level evaluations that require further refinement if thresholds are approached by exposure estimates. For the experimental and epidemiology studies, all suffer from the problem of self reporting and the inherent variability in human response, which clearly varies by sex, age, pre-existing health conditions and prior experiences. Epidemiological studies of odor and health have notably weak exposure assessments, and experimental studies suffer the lack of standardized exposure methods and difficulty carrying out blinded studies . So far, no toxicological study has been able to separate the health effects of odors from those of the co-pollutants in the mixture . The health effects reported by residents living near odor sources may be due to odorless co-pollutants with odor serving as a marker of exposure . Few epidemiology studies, however, look at this possibility. Proximity to an odor source would be a determinant; however, residence distance to the source was often a poor predictor of odor induced health complaints. The sole experimental study of odor , which was discussed in Section 4.3, could not separate the effects of odors from those of co-pollutants in the mixture. Risk perception plays a large role in how exposures to odors can lead to annoyance and outrage. Risk perception has been defined as how the exposed judge the severity of the risk and involves personal and cultural values and attitudes.

Different perceptions of risk are applied to involuntary, imposed exposures, man-made sources and the unfamiliar. Odors often encompass all three of these factors. Key worries from odor exposures include long-term health ailments such as asthma or lung cancer , ability to socialize at one’s own property that is odor impacted, and potential decrease in property value . These perceived risks likely are experienced disproportionately by disadvantaged communities. The air monitoring of the community north of Denver was funded by USEPA as an environmental justice study , and a community well-being study followed shortly thereafter . Participants took an online survey four times over a year. The results at the community level showed that odor-impacted communities had no difference in well-being than the control communities. Individual results, however, showed that respondents who reported that the air was “very fresh” or “odor is highly acceptable” had higher levels of well-being. This finding supports other studies that indicate that unpleasant odors lead to annoyance, general psychological stress, and reduced quality of life. Researchers in Australia studied environmental justice and odors around Melbourne . They used a novel cluster approach to represent communities affected by odor and concluded that self-reported odor exposure correlated with indicators of socio economic disadvantage in the community clusters affected by odor.Large gaps exist in the dataset used to evaluate the health risks posed by odors. Chief among these is the lack of dose-response studies for total odor exposure rather than just for individual odorants. Only a single experimental study of odor mixture exposure and health effects has been conducted . Clearly, more studies are needed, especially measuring physiological and psychological responses simultaneously so correlations can be determined. Longitudinal “before-and-after” epidemiology studies are needed to determine the magnitude of impact of installing an odor-emitting facility near a neighborhood.

For example, the large health-effects study in California after the natural gas leak in Aliso Canyon would benefit from pre-leak community health data. To aid exposure assessment, analytical techniques and sampling require improvement. For one set of odorants – additives to natural gas to impart odor – broad availability of laboratories with the capability to measure sulfur compounds at sufficiently low detection limits is both a health and a safety need . Both short- and long-term health-effect studies of these natural gas additives are also needed. Self-reporting of health symptoms, which is subjective, needs to be replaced with objective measure to make scientific progress in odor risk assessment. Odors add a substantial layer of complexity to traditional human health risk assessment. First, they lead to two types of sensory responses – irritation and smell – that are entwined. Together or separately, these senses, when overwhelmed, can lead to either transitory or more permanent health effects. In addition, odorless co-pollutants can contribute to adverse effects, and their contribution is difficult to separate from that of the odor. Odors are typically mixtures of individual odorants and other airborne compounds, and both odor assessment and conventional risk assessment more easily assess single compounds rather than mixtures. The variability in human responses to odors adds a large degree of uncertainty to any assessment. As with the human health thresholds derived through dose-response bench marking and extrapolation,botanicare rolling benches the odor detection thresholds often have several orders of magnitude of variability between studies and panels. Odor characteristics and the individual’s past experience with the odor, sex, age, culture, mood, personality and health status all influence odor perception. Risk characterizations that use such thresholds are crude at best, and a portion of the population will continue to sense the odor even below the threshold. Several case studies demonstrate that odor thresholds and health thresholds can be applied to odorant exposures to estimate sensory and health effects. How well this odorant-by odorant approach addresses the health risks to communities is an area in need of further research and objective methods. Although there is a general sentiment that marijuana decriminalization has no effect on demand, the more careful evaluations conducted on samples from the United States and Australia have inconclusive findings. For example, studies of decriminalization in South Australia and in the Australian Capital Territory report no changes in marijuana use associated with this legal change, and no differences in marijuana use between these regions and non-decriminalization regions of Australia. However, two recent studies using individual level data from the National Drug Strategy Household Surveys do find a positive effect of decriminalization . In theory, any deterrent effect of levels of marijuana sanctioning should be mediated by citizens’ perceptions of their certainty and severity.Various lines of evidence suggest that citizens may have distorted or biased beliefs about sanctioning threats . Thus, a possible explanation for the inconsistency in decriminalization effects in the literature is that citizens’ perceptions may not vary in accordance with differences in law or enforcement. To address this question we examined data on knowledge of U.S. state laws from the 2001 National Survey on Drug Use and Health . The NSDUH is an annual national household survey of the non-institutionalized U.S. population 12 years and older conducted by the Substance Abuse and Mental Health Administration . It is the primary source of information on the prevalence of use of illegal drugs for the U.S. population.

Since 1999, approximately 70,000 individuals have been interviewed each year across the United States with at least 900 respondents in each of the 50 states. Great care is taken to ensure that information on illicit drug use is accurately reported. For example, the questions on illicit drug use are self-administered through a computer assisted interview survey, no names are used or collected during the interview, and interviews are conducted in private settings away from other people in the household.In 2001, the NSDUH included questions for the first time pertaining to the individual’s knowledge of state marijuana laws. All individuals taking the survey were asked, “What is the maximum legal penalty in for first offense possession of an ounce or less of marijuana for your own use?” Possible responses were a fine, probation, community service, possible prison sentence, mandatory prison sentence, and Don’t know. Information on the weighted fraction of the state sample reporting specific penalties were aggregated to the state level and made available to us by the Office of Applied Studies at the Substance Abuse and Mental Health Services Administration . To these state aggregated data we merged information on each state’s statutory penalties associated with possession of one ounce of marijuana for first time offenders.The penalties represent laws in effect as of January 1, 2001, and were collected and analyzed by a team of lawyers and policy analysts at the MayaTech Corporation. Penalties that were captured include the minimum and maximum jail term, minimum and maximum fine, conditional discharge provisions, and expungement provisions for the lowest two quantity trigger amounts, which capture amounts of one ounce or less for all states.The conditional discharge variable reflects instances where compliance with the specified conditions leads to a dismissal of charges. The first column of Table 2 presents the fraction of the state population reporting a particular maximum penalty across all states, regardless of the state’s actual penalties. On average we see that nearly one-third of the population do not know what the maximum penalty is for marijuana possession offences in their state and another third believe that possible or mandatory jail is the maximum offence. What is particularly surprising is the result that 6% of the population reports that mandatory jail is the maximum offence for possession of an ounce of marijuana. This is surprising because no U.S. state requires a mandatory jail time for marijuana possession offences. To evaluate whether individuals understood the maximum penalty for possession of marijuana in their state, we differentiated states based on their statutory provision of jail sentences. We first separated states based on whether they were recognized in the literature as having a decriminalization policy or not . Although we showed in Table 1 that these policies do not reflect actual differences in the criminal status of marijuana offences, it may be the case that the mere label that has been applied to these states for the past 25 years might generate a greater awareness of the state’s actual penalties for those living within these states. If people living in decriminalized states were actually aware of this labeled policy , then we would expect that they would be less likely to report jail as the maximum penalty and more likely to report fines, probation, or community service as the maximum penalty than people living in non-decrim states.

The panel is held in an air conditioned room with no scents or in the field at the location of the odor. Panelists are trained to distinguish odor mixtures and the intensity of each odorant. Panelists are presented with mixtures of 2, 3, and 4 standard odorants and are asked to identify the odor characteristics and the intensity of each odorant. Panelists are then ready to analyze actual environmental odor samples.Before panelists are exposed to samples, a safety evaluation determines that the odorant concentrations are below safety thresholds . Samples are presented in bags and smelled by panelists, who then write down the odor notes and odor intensities. The leader then leads a discussion, and panelists may alter their decisions. Breaks are taken to avoid odor fatigue or health symptoms . The first challenge with OPM is that it usually requires confirmation by GC-sensory analysis to identify the odorant . The second challenge is that OPM usually operates outside the range of its calibration. The calibrated intensity scores are in the range 4 to 12, yet individual panelist scores – as well as the overall geometric mean – are usually in the 1 to 3 range. Such below-range extrapolations are not allowed in sound analytics. Data sets from analytical chemistry instruments have the same challenge and the temptation to extrapolate lower than the method detection limit. A concern is that there is no evidence that OPM is reproducible across panels . The group discussion may lead to the dominant person biasing others despite instructions to conduct independent evaluations . Substantial training is required. A similar approach to OPM is used in dentistry research for mouth odor .

The scale is 0 to 5 ,cannabis drying racks commercial and extrapolations to 0 are used to predict the ODTC50. This approach has led to good agreement with ODTC50 values from the literature. Another odor-intensity measurement system is used more widely than OPM. ASTM Standard E544 uses various vials with dilutions of n-butanol in water to assign n-butanol-equivalent concentrations to the intensity of a given sample. The upper limit of this equivalency scale appears to be the saturation limit of n-butanol in water rather than a sensory upper limit. The intensity of the odor sample is expressed in mg/L of n-butanol, with a larger value of indicating a stronger odorant. Whole-sample, undiluted total odor analysis is relatively straightforward. Determining the odor notes can lead to indications of the source and even a subset of the individual odorants. An odor-intensity rating of the overall mixture, however, is more controversial and less useful. Duration information can be added to a decision-making matrix, too. For example, a field panel made observations using OPM at three off-site and four on-site locations at a trash transfer station .As an odor mixture is diluted, the odor notes and hedonic tones change and eventually, after sufficient dilution, the concentration of the final detectable odorant drops below its odor detection threshold so the diluted sample becomes “odorless” . The amount of dilution required to reach this point is considered an indicator of the odor intensity of the initial, undiluted sample, which is problematic because the final detectable odorant may not be indicative of the odorant that dominated the odor of the undiluted sample . Relying on dilution quantities to indicate the intensity of the total odor is crude at best and misleading at worst. Further, presenting a dilution quantity as a measure related to the mass of odorants in the undiluted sample, when in reality it measures only the final detectable odorant, adds an unknown amount of uncertainty to such claims.

For a single odorant in isolation, dilution-to-threshold tests are more straightforward. Although the odor note and hedonic tone of the odorant change as concentration changes, sometimes flipping from unpleasant to pleasant, the interactions with other odorants are not factors. Complaints about single odorants are typically limited to the chemical and petroleum industries, however. Research on single odorants is used to tease apart the underpinnings of total odor in mixtures . Dilution of field samples can mimic the dilution that occurs from source to fenceline. Figure 3.5 includes the “unmasking” of musty odor note that was initially covered up by a more dominant fecal and sulfur odor notes at a WWTP . On-site workers would experience the fecal and sulfur odors, while nearby residents complained of musty odors.Portable dilution instruments can be used by field investigators . In the United States, such instruments include the Nasal Ranger® and Scentroid SM100 . Both mix the ambient air being sampled with odorless air at variable ratios. The ratio at which the odor disappears is defined as the dilution-to-threshold ratio. This term tends to be reserved for field measurements, while OU tends be reserved for indoor panels. Both are dilution levels and not mass-based concentrations. A mixture of odorants was tested using both devices . The Nasal Ranger®, which has settings from 2 to 60 dilutions, performed well between 3 and 30 dilutions. For the Scentroid SM100, which has set points from 3 to 101 dilutions, the settings were about half what the test actually showed, possibly due to odorant sorption to internal surfaces. Field dilution devices avoid the need for sample collection, storage and transport. They may have sorption issues, however, and appear to be better suited for low odor concentrations.Field odor measurements may also involve a panel, such as the use of OPM at an impacted school near a landfill site in California , a trash transfer station in California and a landfill in France .

For the landfill study , an abbreviated version of the grid and plume methods discussed next were applied on a single day as well as OPM. The dominant odor notes were “rotten vegetable” and “rancid,” which had high or medium odor intensities. According to the landfill odor wheel, the associated odorants were fatty acids and sulfur compounds , which have very low odor thresholds. Confirmation of odorants by GC-MS-sensory was not performed. In Europe, field panels are central to the grid and plume methods . Figure 3.6 includes general guidance for such a field panel, Figure 3.7 shows how the grid method is applied, and Figure 3.8 shows how the plume method is applied. Both methods require trained panelists to decide whether they recognize an odor note selected from a list. The grid method is applied over a sufficiently long period of time to provide a representative map of the exposure of the population to recognizable odors. Field panelists write down their observations every 10 seconds for 10 minutes . If 6 of those observations are a recognized odor note, then the label “odor hour” is applied . The plume method is used to determine the area in which an odor plume can be perceived under specific meteorological conditions. The odor-plume boundary is where the odor no longer is detectable, and panelists mark yes/no on a map as they walk through and out of the plume. Adding OPM to the grid or plume method provides an intensity scale and can indicate suspected odorants from odor wheels .To confirm and support the sensory analysis of environmental odor exposures, traditional analytical chemistry air monitoring methods are used. A substantial review of analytical and sensory methods for odor measurement was conducted previously . The methods that have advanced since then are the focus of this section . The other methods are covered briefly for completeness. The comparative advantages and disadvantages of these methods are discussed in Section 4.4. Chemical analysis is most appropriate in cases where known single odorants are responsible for an odor,vertical grow racks as opposed to diverse mixtures of odorants. The list of odorous compounds that may be measured is virtually endless. For example, over 400 odorants were detected from swine facilities . Although the level of each odorant was low, the overall mixture led to extremely strong odor intensities. In this case and others, sensory measurements lead to better estimates of odor intensity than analytical measurements. Analytical measurements are only performed for risk assessment when method detection limits are sufficiently low to be below the hazard benchmarks of concern. To achieve such, the human nose is typically required for odor assessment. Although the identification and quantification of specific odorants does not directly indicate the potential odor nuisance, the information is useful for identifying and tracking odor sources . Further, it can help indicate the reactions leading to odorant formation, especially microbial reactions at WWTPs, landfills and composting sites.Gas chromatography, which separates and quantifies odorants, is useful for complex mixtures of chemicals at trace levels, especially on-site where concentrations are higher. Recent advances include two-dimensional and multidimensional gas chromatography , which decrease the analytical problems associated with peak overlap. Both aid in odorant identification. Although detection reaches ppb levels , trace odorants still go undetected, as do odorants that are unstable during sample collection and transport . Identification of unknown peaks from gas chromatography is typically by mass spectrometry and its libraries of thousands of known compounds. However, even knowing the identity of an odorant does not tell how it contributes to the overall odor of a mixture. Such instruments are expensive, as is there operation and maintenance.

A new, albeit even more expensive, instrument has been used for odor investigations called “selected ion flow tube mass spectrometry” . It is transportable and can detect and quantify the concentrations of 20 to 50 odorants real-time, even if the levels are changing rapidly. The SIFT-MS instrument directly measures components of the air by first using chemical ionizing agents on the sample followed by mass spectrometry . The chemical ionizing agents include cations and anions . The analyte concentration is found from the ratio of the product ion counts to the reagent ion counts, the flow rate, and instrument calibration. Low-ppb detection has been achieved.Gas chromatography with a sensory port , often performed in tandem with mass spectrometry , is a hybrid technique that brings together the separation of odorants and the sensitivity of the human nose. The sensory port allows the analyst to smell the eluting compounds at the same time the instrument detector makes a reading. When successful, it can indicate which odorants contribute to the total odor. Recent advances in GC-sensory methods include improved GC-port interfaces, increasing the number of simultaneous panelists , bi-dimensional GC techniques and sophisticated data processing . Disease detection is an emerging use of GC-sensory.Gas-specific sensors can target key odorants but not the total odor. They are often portable, relatively inexpensive, and continuously log data. The most common gas-specific sensors are for hydrogen sulfide and ammonia. Detection is through chemical, electrochemical, catalytic or optical signals. Some can reach ppb levels. Hydrogen sulfide, however, does not account for the entire odor nuisance. At WWTPs, hydrogen sulfide levels can be well controlledand monitored continuously, yet nuisance odor complaints persist . Benzene, a carcinogen, is a problem emitted from oil refineries and gasoline stations, as well as from the semiconductor industry. Advanced sensors using metal-oxide detectors have been developed that can work in various levels of humidity and interferants .Improved sensor technologies and advanced computational techniques have merged to produce non-specific gas-sensor arrays that try to mimic the human sense of smell. Often called an “electronic nose” or “e-nose,” a bank of up to 30 sensors generates a complex electronic signal that is processed through computer algorithms. The result is a reading – but not a true “fingerprint” – for a known odor that then can be compared to signals from future samples to see if they match. When properly calibrated, e-noses should continuously detect the presence of odors in ambient air, estimate concentrations of odors, and attribute the odor to a specific odor source . The sensors are typically a variety of metal oxides, conducting polymers and oscillating quartz crystals; however, new sensor materials are under development continually. As with all sensors, they are subject to the effects of temperature and humidity, degradation, poisoning and the need for frequent re-calibration to address drift. It is difficult to find e-noses used outside of research laboratories , which confirmed the observation by Muñoz et al. that their initial promotion had been overly optimistic. Nonetheless, e-noses developed within laboratories, plus accompanying field tests, have led to numerous publications and several recent reviews of the emerging field. Under controlled situations, e-noses have monitored odors.

PKS gene constructs were transformed into E. coli BL21-. For protein isolation, cultures were grown to an OD of approximately 0.6 at 37 C when transcription of the cDNA inserts was induced with IPTG and cultures were grown for an additional 10–12 h at 28  C. His-tagged protein was isolated from the bacteria using the MagneHis Protein Purification System . PKS enzyme assays contained 4 lg protein, 100 mM KPO4 , 5 mM malonyl-CoA, and either 250 lM hexanoyl-CoA or 67.5 lM 4-coumaroyl-CoA as substrates. Boiled protein was assayed in parallel with all reactions. All negative controls showed a lack of product formation. Reactions were incubated for 1 h at 30  C, dried in a Speed Vac, resuspended in 40 ll methanol, and applied to Agilent Tech 1200 HPLC with a Spherisorb 6 l ODS2 separation column. Products and reactants were resolved across a gradient of 1% H3PO4 to 100% acetonitrile with molecular weights determined by LC-MS.Quantitative reactions were performed as described previously using primers listed in Supplementary Table 4B at JXB online. Equivalent quantities of RNA isolated from glands and inflorescence associated leaves were used to generate the respective single stranded cDNAs. qPCR reactions containing equal quantities of gland or leaf cDNA were run in duplicate along with reactions containing standards consisting of 100-fold sequential dilutions of isolated target fragments, on a Lightcyler qPCR machine . Lightcycler software was used to generate standard curves covering a range of 106 to which gland and leaf data were compared. Two biological replicates were used to generate the means and standard deviations shown in Supplementary Table 4A at JXB online. These values were used to compute the gland over leaf ratios and P-values shown in Supplementary Table 4A at JXB online.

Raw relative expression data, means, standard deviations, P-values from gland versus leaf t tests, qPCR primer sequences,clone rack and representative real-time qPCR tracings are shown in Supplementary Table 4A at JXB online.Anatomical study revealed that glands located on mature floral bracts of female plants are the site of enhanced secondary metabolism leading to the production of THCA and other compounds in Cannabis sativa . These glands are located on multicellular stalks and typically are composed of eight cells . The outer gland surface is composed of a smooth capsule covered by a membrane. The capsule contains exudates derived from the gland cells . The weakly attached glands can easily be separated from the bracts and purified as shown in Fig. 1E and F. An EST library was constructed using RNA isolated from purified glands. Over 100 000 ESTs were cloned. Plasmid DNA was isolated and sequenced from over 2000 clones. Because of the directed orientation of cDNA insertion, sequences are expected to represent the coding strand. After the removal of vectoronly, poor quality sequences, and sequences obviously originating from organelles or ribosomal RNA, the remaining sequences were clustered into 1075 unigenes . Overall, 111 of the unigenes were contigs containing two or more closely related ESTs . Only 14 contigs lacked a similar sequence in the NCBI database. Nine hundred and sixty four of the ESTs were only found once and of these 710 were similar to sequences in the NCBI database . The top three unigenes representing the greatest number of ESTs encoded proteins related to metallothionein, RD22-like BURP domain-containing proteins, and chitin binding hevein-like proteins . All three of these proteins have functions related to biotic or abiotic stress responses . Gene Ontology analysis was performed on the sequence dataset . An analysis of biological function indicates that 27% of the unigenes encode proteins with metabolic activity.

Unigenes with NCBI matches encoding proteins with unknown function comprise 14% of the total and another 28% are predicted to be involved in various cellular processes such as protein synthesis and protein degradation.The specific biochemical steps leading to THCA are proposed to begin with a reaction involving a type III PKS enzyme that catalyses the synthesis of olivetolic acid from hexanoyl-CoA and three molecules of malonyl-CoA . Malonyl-CoA is derived from the carboxylation of acetyl-CoA. ESTs encoding acetyl-CoA carboxylase were identified. Hexanoyl-CoA could be produced by more than one pathway in the trichomes. One route to produce hexanoyl-CoA would involve the early termination of the fatty acid biosynthetic pathway, yielding hexanoyl-ACP . The hexanoyl moiety would then be transferred to CoA by the action of an ACP-CoA transacylase or it would be cleaved by the action of a thioesterase, yielding n-hexanol, which would then be converted into n-hexanoyl-CoA by the action of acyl-CoA synthase. Most of the enzymes needed for this route are represented in the EST database, except for thetransacylase and 2,3-trans-enoyl-ACP reductase . A second route to hexanoyl-CoA would involve the production of hexanol from the breakdown of the fatty acid linoleic acid via the lipoxygenase pathway . A survey of the sequenced ESTs revealed candidate genes encoding the enzymes needed to synthesize linoleic acid from acetyl-CoA by the typical fatty acid biosynthetic pathway in plastids followed by the production of hexanol from linoleic acid via the LOX pathway. An third pathway related to the biosynthesis of branched chain amino acids has been proposed to be involved in the production of short-chain and medium-chain fatty acids . However, the enzymes in this pathway [2-isopropylmalate synthase, 3-isopropylmalate dehydratase, 3-isopropylmalate dehydrogenase, and 2- oxoisovalerate dehydrogenase ] were not represented in the Cannabis trichome EST library.

After the formation of olivetolic acid, a prenyltransferase is proposed to add a prenyl group derived from geranyl diphosphate to create cannabigerolic acid. GPP is derived from the fusion of two isoprene units . Two different biochemical pathways support the synthesis of isoprenoids in plants . Within the list of unigenes all but one of the enzymatic activities needed to convert pyruvate and glyceraldehyde-3-phosphate into isopentenyl and dimethylallyl diphosphate via the methylerythritol 4-phosphate pathway were represented . This finding is consistent with isotopic studies showing that the GPP cannabinoid precursors are synthesized via this pathway . The formation of GPP is mediated by GPP synthase. Several unigenes related to GPP synthase were identified , however, they were more closely related to other terpene synthases. In particular, CAN36 and CAN55, which possibly were derived from the same gene, and the closely related CAN37, are most similar to hop sesquiterpene synthases HISTS1 and HISTS2 , with an average identity of 56% over the first 160 amino acid residues . CAN41 is most similar to hop monoterpene synthase HIMTS2 .The nature of the prenyltransferase is unknown. However, previous studies identified a soluble aromatic geranylpyrophosphate:olivetolate geranyltransferase in the extract of young leaves with the appropriate activity . The only EST encoding a predicted prenyltransferase was CAN121. However, the encoded protein is more closely related to members of the membrane-bound chloroplast-localized family of prenyltransferases than to soluble prenyltransferases . The final step in the pathway is mediated by THCA synthase, which mediates the conversion of cannabigerolic acid to THCA . Two ESTs with sequences identical to the previous reportedly THCA synthase were identified .Whereas the nature of the prenyltransferase responsible for the synthesis of cannabigerolic acid is unknown, three unigenes, CAN24, CAN383, and CAN1069, comprising eight, one, and two ESTs, respectively, could encode the PKS activity needed to synthesize olivetolic acid. These were therefore characterized in more detail. All three unigenes were represented by individual ESTs encoding complete PKS polypetides. These were sequenced and compared to related PKS sequences . CAN1069 was identical to a previously identified Cannabis gene encoding a chalcone synthase, and is the most closely related of the PKS sequences to other known chalcone synthases from hop and Arabidopsis . The relationships of hop phlorisovalerophenone synthase , which mediates the conversion of malonyl-CoA and isovaleryl-CoA to phlorisovalerophenone, to CAN24 and CAN383 is less clear . CAN24 and CAN383 show 64.6% identity and are nearly equally similar to hop VPS at 71.2% and 72.0%, respectively. The enzymatic activities encoded by CAN24 and CAN1069 were explored in detail. The coding regions of the two genes were inserted into the pHis8 vector in frame with a His8 tag. The tagged proteins were purified on a nickel-containing magnetic bead matrix and were assayed for chalcone and olivetol/olivetolic acid synthase activities . Recombinant protein from CAN1069, but not CAN24,hydroponic shelves produced reaction products when incubated with coumaroyl-CoA and malonyl-CoA . The reaction products were analysed by LC-MS and peak 2 was found to have a molecular mass and absorption spectrum consistent with naringenin , the major product of chalcone synthases. Both CAN24 and CAN1069 were capable of using malonyl-CoA and hexanoyl-CoA as reaction substrates and LC-MS indicated that products of these enzymes were the same, but neither molecular mass nor the absorption spectrum of this product matched olivetol or olivetolic acid . Results similar to CAN24 were obtained using protein purified from CAN383 .

Genes required for THCA production are probably more highly expressed in glands of pistillate inflorescences because this is where THCA is most highly concentrated. To test this hypothesis, the relative expression levels in isolated glands versus young inflorescence-associated leaves of selected unigenes were compared using real-time qPCR. The identity of the genes assayed and the differences in relative expression levels are listed in Table 2 and in Supplementary Table 4A at JXB online. Consistent with this hypothesis, THCA synthase expression was 437 times higher in isolated glands than in leaves. CAN24 was expressed 1600 times higher in glands of the inflorescence than in associated leaves. CAN1069 encoding CHS was also more highly expressed in glands than leaves . The expression of a third PKS, CAN383, was expressed at similar levels in glands and leaves . These results are not explained by poorRNA isolation from leaves as unigene CAN219 encoding chlorophyll A/B binding protein showed elevated leaf expression levels . The activities of several housekeeping genes were also tested. A relatively modest increase in levels of histone H2A and beta tubulin expression in glands compared to leaves was detected. The increase in expression levels of these latter two genes might reflect a combination of the heightened metabolic activity and the unique cellular structure of glandular trichomes. Two different pathways could provide the hexanol required for olivetolic acid synthesis, as shown in Fig. 2. Expression levels provide support for the de novo pathway as a primary source, given that CAN498, CAN82, and CAN915 were much more highly expressed in glands than leaves , whereas the relative expression of genes encoding enzymes in the lipid breakdown pathway were depressed or modestly elevated in glands.Eighty Cannabis unigenes were similar to transcription factors found in Arabidopsis and 11 contain MYB DNA binding domains . Expression of four MYB genes in isolated glands and leaves was compared by real-time qPCR . CAN833 and CAN738 exhibited 954-fold and 586-fold higher expression in glands, respectively, whereas CAN483 and 792 showed more modest induction in glands. None of the other putative transcription factors that were assayed showed the same degree of differential expression as CAN833 and CAN738 .The identities of the most abundant ESTs derived from the glandular trichomes of Cannabis sativa are consistent with the protective function of plant glands. For example, themost abundant ESTs encoded a protein closely related to type II metallothioneins. These proteins bind heavy metals such as Cd, Zn, and Cu, and their proposed primary function is the maintenance of Cu tolerance . The second most abundant class of ESTs encoded an RD22-like BURP domain containing protein. This class of proteins contains a hydrophobic Nterminal signal peptide, and an N-terminal conserved region followed by a series of small repeats . The BURP domain of approximately 230 amino acids is located in the C-terminal region. The function of RD22-like proteins is unknown but some members of this class of genes are induced by dehydration . The third most abundant ESTs encoded a protein containing a hevein domain. Hevein domains contain a conserved 43-amino acid motif that binds chitin and members of this protein class are known for anti-fungal activity . The unique secondary metabolism in Cannabis may also play a role in plant defence. Synthesis of THCA is extracellular and results in hydrogen peroxide production, which has general antimicrobial properties , and a recent report further indicates that THCA may directly inhibit microbial growth . The analysis of gland-derived ESTs has identified nearly all the candidate genes required for THCA synthesis from primary metabolic products.

Wind direction, speed and temperature are measured using a hand-held Kestrel 1000 meter, and the cloudiness and weather are noted. More sophistical meteorological data has been used to calculate the back-trajectory of odor plumes using data from the National Weather Service in MesoWest plus the HYSPLIT dispersion model. Odor investigation data is captured in an in-house database that is rather old and does not allow for easy queries. Since 2010, the number of odor complaints per year has risen from around 3,400 to 7,500, decreasing in 2017 to 6,000 . Odor complaints are received by phone or via their website, which is also available through their app.No electronic nose technology is currently used although a report surveyed dozens of emerging technologies . The authors noted that e-noses were primarily used for quality control for food and other products, and that a large effort would be required for field tests for environmental odor detection. Two major case studies from SCAQMD are informative. The first case is metallic odors in the industrialized section of the City of Paramount that began in 2013 . Nickel and hexavalent chromium were detected in air samples. Three businesses with metal-related operations were identified and many community meetings were held to address both odor and air toxics concerns. Under an Order for Abatement, one company was required to take measures to reduce odors in July 2017. They improved air pollution controls in their grinding room and made other improvements, and the number of odor complaints decreased. The second case is the coastal area of Seal Beach, Huntington Beach, and Long Beach that experienced “gas/sulfur/chemical” odors . To help find the allusive source, sampling was performed between March 2017 and October 2018 in partnership with local fire departments. SUMMA canisters were analyzed for the presence of volatile organic compounds,vertical farming equipment suppliers and samples collected in Tedlar™ bags were analyzed for total reduced sulfur compounds.

Crude oil was the likely source of the compounds detected, and in October 2018 a violation was issued to an oil tanker that, upon inspection, had 7 out of 10 pressure release devices leaking . Portable hydrocarbon-sensing devices and gas imaging cameras were used to detect the leaks. Monitoring for other sources using a forward-looking infrared camera and further sample collection are ongoing. To address the beach communities’ health concerns from the intermittent exposures, and to put the monitoring data into context, a “frequently asked questions” document was created . The conclusions were that the levels of hydrogen sulfide were below the 30 ppb one-hour state standard, the levels of specific hydrocarbons were below their acute limits, and that cancer risk was not at a level of concern due to the intermittent nature of the exposures.The Bay Area Air Quality Management District , headquartered in San Francisco, sets an odor limit of 5 dilutions-to-threshold at or beyond the facility fenceline, which is applied after at least 10 complaints are received within a 90-day period . Further investigation is required if a further 5 complaints are received within the next 90 days. Interviews with staff provided recent information and insights into investigation techniques currently used. Although still found in their local regulations, the use of odor panels to evaluate samples captured in bags ended over five years ago. The primary concern was that employees, who served as the panelists, were worried about exposures to unknown compounds and experienced negative sensations. Using air monitoring results for specific odorants and comparing the concentrations to odor detection threshold concentration was considered not in line with odor being a sensory nuisance . Lacking any quantifiable sensory method, air inspectors now conduct source-by-source investigations using their own sense of smell with moderate success. An inspection is triggered when 5 or more independent complaints are received and can result in a Violation Notice. Although their “Odor Policies and Procedures” is currently being revised, BAAQMD has several experiences worth sharing.

When an odor complaint is received during office hours, within 15 minutes it is assigned to an air inspector who has 30 minutes to contact the complainant. They then meet, experience the smell together and walk toward the source together. No sensory descriptors or training are used. They also explore upwind. If the odor is verified, the source is contacted and, if needed, inspected to see if in violation of the permit. Prior attempts to use field olfactometry offered no advantages to the above method. A database developed in-house manages the case load. Regarding odor management plans that facilities have submitted, the air inspectors found substantial difficulties. Such plans are difficult to enforce, different for each site, written by a third party , and require large amounts of staff review time. Regardless, they are commonly found at WWTPs and trash transfer stations. A prior contract with Envirosuite Inc. was not continued due to the substantial requirements for meteorological data. The project tried to use advanced backtracking technology, based on real-time fine-scale meteorological modelling, to instantly plot and visualize the trajectory of an odor complaint, thereby identifying its likely cause. A current challenge is the overlapping odors found in Milpitas, which have resulted in thousands of complaints. To fingerprint and identify which sources are contributing to the ongoing odors, BAAQMD issued in March 2019 a request for proposals . A community group that meets quarterly is conducting a parallel study. Another challenge is the increase in composting operations, which are often malodorous. Finally, an emerging area of concern is cannabis cultivation, particularly within and around Santa Rosa, California. To understand the operations, BAAQMD staff toured a cannabis cultivation facility and will visit again.To become a “verified complaint,” air inspectors from the Sacramento Municipal Air Quality District rely on the definition of nuisance being about the complainant’s perception and try to verify that. Upon meeting the complainant, the air inspector logs their own description of the odor and sees if it matches that of the complainant. Standardized smell vocabulary would be useful. A verified odor nuisance can lead to a Notice of Violation, which in turn can lead to an Abatement Order that shuts down the facility. The owner must then sue to re open the facility. SMAQMD is considering trying a field olfactometer like neighboring air districts have. Previous tests conducted at the source of an odor need to be translated to fenceline concentrations experienced by the neighborhood.

A current challenge is a rendering facility. California law, the Right-to-Farm Act, exempts such facilities from nuisance law, however. Another challenge is a sweet potato drying operation that has rotting odors. Also, the Zero Waste initiatives are sending more scraps to compost facilities, which are exempt from air regulations, so solid waste programs handle the complaints . Even pleasant aromas can become nuisance odors. A blueberry smell from a food factory was intense enough to trigger migraines. Masking has been done using cherry “perfume” at a solid waste landfill. Complaints are logged into a database that contains over 13,000 records since 1996. The data was transitioned from MS Access to MS Sharepoint, which sends automated e-mails and allows for logging from the field. Responses to questions were received by e-mail from the Feather River Air Quality Management District . Nuisance odor complaints are infrequent and primarily regarding agricultural operations, which are exempt from investigation. For other sources, air inspectors gather from the complainant the type of odor, location, wind direction, topography and any adverse effects experienced. All complaints are investigated, and the air inspectors rely on their own sense of smell and best judgment to trace the odor to the source. The source usually acts immediately to mitigate the problem.Air inspectors from Placer County Air Quality Management District respond to all odor complainants. They drive to the complainant and try to verify the odor, even if they need to wait for an intermittent odor. If detected,grow light shelves they then try to identify the source. No cases have ended up in court, just resolved by mutual settlement. Past experience with a field olfactometer was not helpful due to the transient nature of most odors. The major source of odor complaints is a landfill. The dispersion modelling was not helpful, and sampling was sent for odor intensity testing by a panel. A spray coating did not stop the odor, nor did a cherry/citrus mist at the perimeter. The latter actually magnified the odor. Another nearby source, bioenergy wood piles, was blamed for the odors by the landfill.The San Joaquin Valley Air Quality Management District covers eight counties. Once a complaint is received, the air inspector visits the complainant to determine the type of odor, time of day and GPS location. Driving around, the source is identified. If the source is a permitted facility, the air inspector goes on-site to review the permit and inquire about any upsets or disruptions. If not permitted, the air inspector talks with the source and offers compliance assistance and education. The air inspector always circles back to the complainant to communicate the findings. A senior air inspector often accompanies a new inspector to provide mentoring. Once source of odor complaints was from residents who disagreed with urban planning decisions. Other complaints were from a WWTP that had a pond go anaerobic and a rendering plant, which is now closed. Their database could serve as a model for other air districts. It was developed in-house, which was expensive, but the functionality is impressive. The database is on-line, smart phone friendly, interfaces with their app and, thus, can collect photos and videos. The system sends automated notifications to inspectors by text or e-mail.

It also includes mapping features.Three odor experts in the Colorado were interviewed by phone. Adam Wozniak, an odor expert in the stationary sources program, provided an overview of Colorado’s approaches to nuisance odor investigation. Colorado has the same number of stationary air pollution sources as California, yet a much smaller population. A recent case was odors from a bio-fuel operator north of Denver, which required community meetings. A study of odor’s impact on wellbeing in North Denver has been published . Colorado has 25 odor inspectors at the state level. Most complaints, however, are delegated to the local officers. Both state and local air inspectors are certified annually on how to conduct sensory investigations through a class offered every other month. Odor inspectors are trained to avoid the use of odor notes and instead focus on “detectability,” which is a faint sense that an odor is present, rather than “recognition,” which is a clear sense that an odor is present and can be described. Inspectors’ ability to detect odor intensity, on a scale of 0 to 10, is tested using a “detectability rating test” , and those with extreme senses of smell are disqualified from odor inspections. The Colorado odor regulation from the 1970s, Regulation 2, is a bit of a curse. Regulation 2 codifies field olfactometry dilution-to-threshold limits that are violations when exceeded, namely 2:1 for hog odors, 7:1 for residential/commercial odors, and 15:1 for other land uses . Regulation 2 is a problem because the public complains of odors well below these limits, generally around 2:1 or 3:1. Regardless, to comply with the regulation, field olfactometers are used, primarily the Nasal Ranger® because the more affordable Scentometer is no longer manufactured. The Nasal Ranger® has been customized to meet the dilutions required for Colorado . Persistent complaints receive a 10-day evaluation with follow-up 14 to 30 days later. The evaluation includes mapping of odor frequency, wind direction, and upwind locations. Due to the relatively high D/T limits, few violations occur, and none have ended up in litigation. More commonly, the public is upset with the agency that no violation was triggered. All complaints are tracked in CACTIS software, as is all inspection work. William Brennan at Denver Public Health and Environment was also interviewed by phone. Legal adult use of cannabis began in Colorado in 2014, and today over 350 cannabis cultivation facilities are found within the city limits of Denver. A sharp increase in odor complaints accompanied the rapid growth. Some were probably from disgruntled voters who opposed the legalization. An advisory work group was formed to tackle the issue and included a variety of stakeholders that attended 10 meetings. New odor regulations were developed that now require cannabis growers, edibles manufacturers, and a few other industries to submit Odor Management Plans. An outline is provided as well as example plans.

This is more challenging with a subset of the Taxol P450s that are predicted to have multiple transmembrane domains with an uncharacterized ER-binding mechanism. Modifying this interaction without disrupting the internal loop structures and catalytic activity of the protein could prove quite difficult. Another aspect of P450 function is often determined by peripheral protein-protein interactions in the native host. Many highly modified plant natural products are synthesized by a collection of enzymes in complex along the ER membrane called metabolons, with the intermediate substrates shuttled from one reaction center to the next. These highly optimized systems often involve non-catalytic “scaffold” proteins that act as a foundation for the binding and assembly of numerous enzymes. Examining the expression and localization dynamics of Taxol-associated P450s revealed a deficiency in ER localization when tested in their native form in yeast. Expression was seen for all the P450s investigated, but they localize to the cytosol. As mentioned earlier, functionality for the vast majority of P450s from plants are dependent on proper ER-anchoring and redox coupling with additional ER-bound enzymes. We sought to modify the localization of Taxol P450s in yeast by substituting the native ER-anchor region for a sequence previously shown to result in proper ER localization in yeast. Structure modeling and transmembrane domain prediction was carried out for six of the Taxol P450s using the PHYRE2 platform. In general, the first transmembrane domain of a P450 acts as the ER-anchor region. We therefore selected the first amino acid after the predicted transmembrane domain for each P450s as a truncation point. The functional ER-anchor sequence was used to replace the truncated region along with the same linker sequence 264 used for the fluorescent reporter protein fusions.

The linker sequence was added with the aim of improving ER localization by introducing flexibility at the fusion site. Unfortunately,rolling hydro tables even with the modified anchor region the P450s fail to properly localize to the ER . Another potentiality for improving the localization and function of multiple P450s is engineering protein scaffolds that promote assembly at the ER membrane. Membrane steroid binding proteins are a class of protein that are commonly involved with biosynthetic pathways in plants. Furthermore, these are often required for functional biosynthesis, exemplified by the lignin biosynthetic pathway involved in secondary cell wall formation. Biosynthesis of the lignin polymer is highly regulated, multi-branched, and includes several P450s requiring a MSBP for complex assembly. By identifying transmembrane domain anchors and MSBPs with a high affinity for interaction, it may be possible to generate pseudo-metabolons when engineering plant natural product biosynthetic pathways into yeast, specifically those that require numerous ER bound enzymes. To test the potential of this application, we selected a MSBP to test in yeast with a previously characterized fusion protein confirmed for functional ER localization . Fluorescent reporters were used to observe the expression and localization of both MSBP and ER-CslG simultaneously to examine co-localization patterns . ER-CslG:eGFP showed proper ER localization patterns in most of the cells observed , while MSBP:mCherry showed varied patterns of localization . It is important to note that there are potential unknown interactions between MSBP and the mCherry fusion protein. In the cells that showed high levels of co-localization though, robust accumulation of both MSBP and ER-CslG can be seen along the ER envelope of the nucleus . The pattern observed seems to represent a nucleation reaction, with co-localization initiation leading to the accumulation of both MSBP and CslG at high concentrations.

This observation exemplifies a prospective method to promote the accumulation and optimum localization of plant derived P450s, as well as providing a secondary scaffold for the “assembly” of multiple P450s simultaneously. While more optimizations would be needed to integrate numerous enzymes into this engineering scheme, the potential of forming pseudo-metabolons could be a favorable approach when engineering bio-synthetic pathways of plant natural products like Taxol in yeast. They are commonly found in plants from the nightshade family, genus Solanum, including tomato, eggplant, and potato. Yeast provides a relatively unexplored opportunity for the bio-production of steroidal alkaloids in a heterologous host. As yeast does not natively produce cholesterol, the primary substrate for steroidal alkaloids, very limited efforts have been made to explore this molecular space for bio-production. Interrupting ergosterol production and shunting zymosterol to cholesterol can be achieved by genetically exchanging ERG5 and ERG6 with DHCR7 and DHCR24267 . Additionally, the substitution of cholesterol for ergosterol in the cell membrane results in limited disruption on yeast growth and development, making this a plausible system to explore. This “humanized” yeast system has been used in studies of mammalian cell-surface receptors and transporters in the past but harnessing this chassis for the bio-production of plant natural products has untapped economic potential268 . Further modifications could be made to optimize cholesterol overproduction and bio-availability, to ultimately produce a S. cerevisiae strain engineered specifically for the biosynthesis of cholesterol derivatives with diverse structures and applications. To explore the potential of yeast as a platform for steroidal alkaloids production, we engineered a cholesterol producing strain using CEN.PK as our parent line. DHCR7 and DHCR24 from humans were selected based on previous work on cholesterol biosynthesis.

Sequential gene substitution of the native ERG5 and ERG6 genes was carried out via homologous recombination. pADH1-DHCR7 was used to replace ERG5 and its native promoter with pADH1-DCHR24 replacing ERG6 and its native promoter, gene substitutions were performed at the native loci. One deficiency of “humanized” yeast is the capacity for acid transport, as cholesterol substitution disrupts endogenous acid transporters. This was observed when performing counter selection for the URA auxotrophic marker used in cloning, which utilizes plating on 5-FOA . This acidic medium, in conjunction with the 5-FOA counter selection , caused a drastic lag in growth for the final strain with colonies appearing more than ten days after plating. Multiple colonies that cleared PCR and sequencing screens were then selected for GCMS analysis of cholesterol production against an analytical standard. Interestingly, two strains were confirmed for cholesterol production but have varied product profiles. Chl24-20 was the top producing strain in this initial screen, with cholesterol being one of two major products in the GCMS analysis. While Chl75-10 did produce cholesterol, it was a minor product, with two other major peaks present . These were not structurally identified but based on MS spectrum analysis are hypothesized to be structurally similar to cholesterol with variation in the number of C-C double bonds. Chl24-20 was selected as our production strain for downstream analysis. While final cell densities of experimental strains and the control strain were equivalent at 72 hours, there was an observable lag in growth for the experimental strains during the first 36 hours of production. This is most likely due to sub-optimum cholesterol production along with peripheral effects of sterol substitution in the developing membranes of dividing yeast. After confirmation of cholesterol production in Chl24-20 with an analytical standard, we used GCMS analysis of Chl24-20 culture extract and a series of five dilutions of cholesterol standard in ethyl acetate, which is the same final solvent used for extraction . These data were then used to generate a standard curve for cholesterol to quantify production in Chl24-20,vertical horticulture which was calculated to be ~128.4nM with our extraction method . Numerous steroidal alkaloids have implications in human health and research including cyclopamine, α-tomatine, and α-solanine. The interest in α-tomatine is due to its function as an antimicrobial that protects the plant against fungi as well as herbivores270. Its broad-range mechanism of action, which involves disruption of cellular membranes as well as inhibition of acetylcholinesterase, makes it a great candidate for further development of antibiotics. α-solanine, from potato, has a similar membrane disruption effect, but is different in its capacity to interact with mitochondrial membranes. It acts as a poison by disrupting the mitochondrial membrane potential leading to a flood of calcium ions into the cytoplasm causing cell damage/death. Cyclopamine is of particular interest due to its interaction with Hedgehog signaling, which is involved with an array of developmental processes including embryonic development and tumorigenesis. Much like Taxol, it has profound implications for its capacity to inhibit tumor growth as a treatment for a variety of cancers, though the mechanism of action is quite different. Cyclopamine is a steroidal alkaloid derived from cholesterol that does not require glycosylation, making it a great target to test the potential of our steroidal alkaloid yeast platform. Verazine is an intermediate in cyclopamine production that has a well characterized pathway requiring three P450s and an aminotransferase. The conversion of verazine to cyclopamine then only requires two additional reactions that are currently being charactered . What is exciting about this pathway is the potential to generate novel glycosylated steroidal alkaloids with the introduction of GTs from either saponin, tomatine, or solanine biosynthesis for the glycosylation of the 3C position .

Recent advances in engineering nucleotide sugar pathways into yeast, coupled with the promiscuous nature of plant derived GTs, provides an opportunity for the biosynthesis of glycosylated steroidal alkaloids. Solanaceous plants produce a variety of these molecules, with diverse physiological applications and effects and therefore have an abundance of genetic material that can be implemented in yeast. The potential to produce novel glycosylated molecules is especially promising, for example glycosylated cyclopamine derivatives, with the introduction of GTs that glycosylate similar structures such as saponins. These new molecules have a greater degree of structural diversity and may provide enhanced, altered, or even novel properties. This specifically demonstrates the utility of synthetic yeast biology as a tool to produce “new-to-nature” molecules not possible with classic organic chemistry or extraction from plants. While further optimizing the production of free cholesterol, we can begin to introduce key nucleotide sugar pathways that produce the substrate for GT reactions, allowing for pathways requiring glycosylation to be investigated. Engineering a yeast platform specifically for the bio-production of glycosylated steroidal alkaloids would be an excellent resource for future studies on these complex and derivatized molecules.While much of the work discussed is varied in its approach or function, its core follows the reductionist theme of synthetic biology, aiming to rebuild living systems for specific applications in biotechnology. Whether engineering a fungus or a plant, the concepts applied remain the same. The amazing diversity of biological systems present on earth are a canvas for synthetic biologists, providing an almost infinite source of genetic information that can be reengineered and reshaped to solve challenging problems. In my opinion, synthetic biology is still in its infancy, but as we collectively increase our knowledge and understanding of the core tenets of life, we will see the true power of synthetic biology emerge. Even with these limits on our current understanding, we are transforming the old industrial economic model into a bio-based economic model. Opportunities for ambitious and clever engineers are abundant, and I predict an exponential increase in the development of novel synthetic systems in the coming decade. So much untapped potential makes this an exciting era for biotechnology, with the prospect for application of bio-based solutions across all sectors. Eventually, the integration of biological systems with digital systems will exponentially expand the possibilities, as electrical and biological process can be intertwined to generate platforms we have yet to imagine, all made possible with synthetic biology. Observing patterns in retail prices is fund a mental for understanding the economics of any agricultural consumer product. The study of cannabis retail prices, like the study of other economic aspects of the cannabis industry, is fraught with difficulty, in part because cannabis remains a Schedule I narcotic under U.S. federal law. Consumer price indexes, tax records, commercial retail scanner data, industry association reports and other sources of data typically available for agricultural products such as wine, almonds and cut flowers are unavailable for cannabis. Cannabis retailers have limited access to banking services; most cannabis retail transactions are conducted in cash; and cannabis businesses are under standably reluctant to share their financial data. There is a need for better information about all aspects of the cannabis industry, including prices and price patterns. In this article, we aim to contribute to the scant literature on cannabis retail prices by describing the basic patterns of price ranges at retailers in California over a 21-month time span during which the industry under went a series of significant regulatory changes. Several times between October 2016 and July 2018, researchers at the UC Agricultural Issues Center gathered cannabis retail prices published on Weedmaps, a leading online cannabis retail platform.

As such, it may be that in the absence of legally available chemical controls growers were choosing allowable, biologically derived products or alternative strategies such as natural enemy augmentation and sanitation. Our survey population was perhaps biased toward non-chemical pest management — the organizations we contacted for participant recruitment included some that were formed to share and promote sustainability practices. Or, it may be that respondents were reluctant to report using synthetic chemicals or products not licensed for cannabis plants. The only other published data on water application rates for cannabis cultivation in California we are aware of is from Bauer et al. , who used estimates for Humboldt County of 6 gallons per day per plant for outdoor cultivation over the growing season . Grower reported estimates of cannabis water use in this survey were similar to this rate in the peak growing season , but was otherwise lower. Due to the small sample size, we cannot say that groundwater is the primary water source for most cannabis growers in California or that few use surface water diversions. However, Dillis et al. found similar results on groundwater being a major water source for cannabis growers, at least in northwest California. If the irrigation practices reported in our survey represent patterns in California cannabis cultivation, best management practices would be helpful in limiting impacts to freshwater organisms and ecosystems. For example, where groundwater pumping has timely and proximate impacts to surface waters, limiting dry season groundwater extraction by storing groundwater or surface water in the wet season may be beneficial ,indoor grow rack though this will likely require increases in storage capacity. The recently adopted Cannabis Cultivation Policy requires a mandatory dry season forbearance period for surface water diversions, though not for groundwater pumping. Our survey results indicate that the practical constraints on adding storage may be a significant barrier for compliance with mandatory forbearance periods for many growers.

More in-depth research with growers and workers is needed to explore the characteristics of the cannabis labor force and the trajectory of the cannabis labor market, especially in light of legalization. Several growers commented on experiencing labor shortages, a notable finding given that recent market analyses of the cannabis industry suggest that labor compliance costs are the most significant of all of the direct regulatory costs for growers . Higher rates of licensing compliance among medium and large farms is not surprising given the likelihood that they are better able to pay permitting costs. Yet, that the majority of respondents indicated they had not applied for a license to grow cannabis, with over half noting some income from cannabis sales, indicates potentially significant effects if these growers remain excluded from the legalization process. More research is needed to understand the socioeconomic impacts of legalization, which likely extend beyond those accounted for in the state’s economic impact analysis, which primarily focuses on economic contributions that a legalized market will bring to the state . Bodwitch et al. report that surveyed growers characterized legalization as a process that has excluded small farmers, altered local economies and given rise to illicit markets. The environmental impacts of cannabis production have received attention because of expansion into remote areas near sensitive natural habitats. The negative impacts are likely not because cannabis production is inherently detrimental to the environment, but rather due to siting decisions and cultivation practices. In the absence of regulation and best management practices based on research, it is no surprise that there have been instances of negative impacts on the environment. At the same time, many growers appear to have adopted an environmentally proactive approach to production and created networks to share and promote best management practices.

Although widely used in discussions regarding alternative marijuana policy regimes, decriminalization is a policy that to date has gone largely undefined in the international policy arena. The term literally implies a reduction in the criminal status of marijuana possession offences; however, numerous countries and sub-jurisdictions that are recognized as having decriminalized marijuana in fact merely reduce the penalties associated with possession of specified amounts. Hence, the term marijuana depenalization has evolved in the scientific literature as a more accurate term reflecting the diversity in policies that exist across countries . Decriminalization, nonetheless, remains a common term used in policy discussions and debates. The ubiquitous use of the term decriminalization does more than obscure meaningful policy differences that exist across countries; it has led to the development and interpretation of policy research that is myopically focused on evaluating the impact of a single dichotomous indicator that is inconsistently defined within and across countries . Thus, it is not surprising that the literature does not provide a clear, consistent conclusion regarding the impact of decriminalization on marijuana use, its harmful consequences, and arrests when these different studies are in fact evaluating different policies. Although all developed countries today prohibit in some fashion the possession, use, cultivation, distribution and/or sale of marijuana and marijuana products, the countries differ tremendously in the types of behaviours that are allowed, the resources devoted to enforcing the laws, the penalties that are imposed on those who break these laws, and their citizens’ knowledge of these policies. Variations in laws, how they are enforced, and the penalties imposed together determine the policy and the public’s understanding of the policy . Hence, those interested in evaluating the impact of specific policies like marijuana decriminalization need to consider more than just the law and a simple binary label for its penalty structure. They must also consider how and to what degree specific policies get enforced in relevant jurisdictions.

This paper provides a framework for understanding what decriminalization means within the broader context of depenalization. To illustrate these concepts, it provides a detailed discussion of a range of depenalization policies observed in developed countries, highlighting for each country a distinct issue that influences how the policy is implemented and its potential impact. Those interested in analyzing or evaluating the impact of these policies can then use this information to better frame analyses so that policies can be evaluated and compared in a more meaningful way. The paper then demonstrates the problem of using a simple dichotomous indicator, such as “decriminalization”, to differentiate policies within a single country using the United States as the example. It shows that presumed differences in knowledge and enforcement of these laws, factors that should be related to a policy of decriminalization, are not consistent with the current labels that have been given to specific states. Decriminalization and depenalization are both terms that represent a range of policies targeting marijuana users in countries where the supply of marijuana for the purpose of recreational use is statutorily prohibited.Hence, these policies do not relate to how the suppliers of marijuana get treated in specific countries. They only differentiate how those caught in possession get treated.Just as apples are a type of fruit, decriminalization is a specific type of depenalization policy. In this paper, depenalization refers to any policy that reduces the penalties associated with possession or use of marijuana. For example,indoor farming equipment policies that retain the criminal status of possession offences but remove or reduce the amount of incarceration imposed as a penalty would be examples of depenalization policies. Decriminalization, on the other hand, refers specifically to depenalization policies that change the criminal status of possession offences from that of a crime to that of a non-criminal offence. Because penalties are usually graduated with the level of crime, a change in the criminal status of an offence will also imply a reduction in the level and type of penalties imposed with that offence, which is why decriminalization policies may be viewed as a special form of depenalization policies. A country that is interested in reducing the criminal justice burden associated with marijuana possession offences could do so in one of at least two ways: retain the criminal status of the offence, but remove any jail time imposed for these offences , or eliminate the criminal status of the offence, which will also eliminate the jail time imposed with this offence .The first method results in an incremental reduction in the burden for the criminal justice system mainly due to reduced incarceration costs, as court resources may still be required to adjudicate cases depending on the legal structure of the jurisdiction. The second method also generates savings due to incarceration, but may produce larger savings if the resources involved in enforcing and processing civil offences are less intensive than those used to enforce and process criminal offences. If this is not the case, then the non-incarceration savings associated with a change in the criminal status of marijuana would simply reflect a redistribution of these costs from the criminal justice system to another government agency.

Fundamentally, the primary difference between these two methods has to do with the outcome for users. Although the specific penalties imposed on users in each of these cases could be structured identically , depenalization retains the criminal status of the offence while decriminalization does not. The importance of a criminal charge depends on the jurisdiction. In some jurisdictions, criminal charges can influence an individual’s ability to obtain and/or retain work, student loans, and public assistance; hence decriminalization can substantially reduce the personal cost associated with getting charged with possession offences. In other, more rehabilitative jurisdictions, criminal charges do not impose these sort of additional personal burdens.There are a variety of different depenalization models that have been adopted in developed countries. Even within specific countries, important variations to the model can exist. Many countries have adopted a policy of “partial depenalization,” in which the penalties for individual users vary on the basis of the quantity of marijuana that they possess and their number of prior offences. For example, first-time offenders who are caught in possession of small amounts of marijuana might receive civil penalties while those caught in possession of larger quantities or are repeat offenders may face criminal charges. Variants of this policy are seen in Australia, Germany and the United States. Other countries have adopted a policy of “full decriminalization,” where the simple possession or use of any amount of marijuana is not a crime regardless of the number of prior offences. These offences remain illegal but have civil sanctions, typically involving mandatory treatment and a fine. Examples of European countries that have adopted policies of full decriminalization include Italy, which initially adopted its policy in 1975 and reinstated it after a brief period of re-criminalization from 1990-1993, Spain, which adopted its policy in 1983, and Portugal, which only recently adopted its policy in 2001.The Netherlands represents the single biggest outlier to marijuana policy models experimented with thus far, as it is the only country that has allowed a small, regulated market to develop. Even in this case, however, the market is severely limited and stiff penalties remain for individuals caught in possession of large quantities of the drug.Since 1986, the goal of Australia’s national drug strategy has been to “minimize the harmful effects of drugs on Australian society” . Efforts to achieve this goal include the provision of education, a significant expansion of treatment and the collection of national data on drug use and drug-related harms . In the Australian Federal system, states and territories are responsible for enacting legislation and implementing drug policies while the Federal government can influence national policy by tying funding for drug programs to compliance with broadly agreed national goals. Consequently, although harm minimization has been the national drug policy goal, there has been no uniform approach to marijuana and several Australian states and territories have experimented with their own marijuana policies . Since the mid- 1980s, five Australian territories have replaced the criminal penalties associated with minor marijuana offences with administrative fines . South Australia was the first to adopt the Cannabis Expiation Notice system in 1987, eight years after the South Australian Royal Commission into the Non-Medical Use of Drugs recommended that marijuana use not be treated as a criminal offence . In 1992 and 1996, the Australian Capital Territory and Northern Territory, respectively, adopted similar systems. Western Australia has just recently made the change in 2003. Other states in Australia have retained the criminal status of these minor marijuana offences, although diversion to education and treatment are now the most common outcome for first offenders in all states.

Gender identity was collapsed into a 3- level categorical variable; transgender and non-binary were recoded to “self-described.” Additionally, I controlled for sexual orientation as a binary variable: lesbian, gay, bi-sexual, or queer and heterosexual. Lastly, there were three variables measuring employment included in the analysis. Employment status was treated as a dichotomized variable with full-time scored as one and part time scored as zero. Employment tenure in cannabis was also treated as a dichotomous variable to in order to gauge seniority in the industry, pre-legalization of recreational cannabis. Employment tenure in the cannabis industry less than two years was scored as zero, and employment tenure longer than two years was scored as one. Respondents chose one of four options, “less than 6 months” , “6 months to 1 year” , “1 year to 2 years” , and “more than 2 years” . Survey data were analyzed using the statistical program, STATA version 16. Univariate analysis was initially conducted to identify observations with missing data and assess demographic information of the sample. Bivariate analyses, using chi-square, were conducted to investigate the relationships between the three dimensions of sexual harassment and independent variables. Significance was assessed at an alpha level equal to 0.05. Multivariable linear regressions were used to assess relationships with frequency of harassment for the 3 sub-scales and the independent variables. Significance for the logistic regression models was also assessed at an alpha level equal to 0.05. Interviews were transcribed by and coded using Dedoose version 8.3.17.

All interviews were coded twice in order to develop and solidify the codebook. Interviews were analyzed using a deductive approach and thematic content analysis to identify salient responses to organizational risk factors of sexual harassment. Table 3 captures frequency, distribution and Cronbach alpha scores for sexual hostility reported by participants. The most frequent item reported was listening to verbal remarks of a sexual nature at an average frequency of 1.47,horticulture solutions representing an occurrence of once to one or more times a month. Respondents least frequently experienced sexual hostility in the form of persistent and unwanted invitations for discussions of a sexual nature. The average frequency for this item was 1.09. In other words, amongst the study sample, workers experienced harassment in this form on average once in the last 12 months. Unwanted sexual attention was, overall, the least common dimension of sexual harassment experienced by respondents, as demonstrated in table 1. The most frequent item reported in this particular category was uninvited touching, experienced less than once by the entire study sample . The item least reported was being witness to obscene images in the workplace . For bivariate and multivariate analysis, items two and three were removed from the dimension of unwanted sexual attention as they had the lowest response rates, and the highest Cronbach alphas, 0.31 and 0.39, respectively. Although the surveys served as the primary source of data for this study, in-depth interviews were conducted in order to provide more descriptive and clarifying insights into the context of sexual harassment that occurs in dispensaries. I was particularly interested in learning from workers how organizational factors may exacerbate experiences of harassment or serve as protective factors. This information was not collected through the survey as it was more exploratory in nature and hearing from workers directly would offer the most accurate insight. Themes of organizational risk factors were drawn from the data by closely examining examples of harassment described by workers.

Their responses often did not focus on the details of the incident itself but its antecedents and consequences. Additional themes captured from the interviews included apathy towards experiences of harassment and a desire for union led training focused on worker’s rights and de-escalation tactics. Although being a victim of harassment was not a requirement for participating in the interviews, all workers described varying levels of experience with sexual harassment in their work environment. Experiences ranged from personally being a target of harassment, witnessing their co-workers being harassed or learning about instances through co-workers. Among the interviewees, two identified as men, and the rest as women . The age of interviewees ranged from 27 to 32 years of age. All interviewees, except one, had previous experience in illegal dispensaries as well as non-union represented shops. This is important to note as respondents often used their past work experiences as a point of reference for describing their current workplace as well as recent experiences with harassment and their company’s responses. The names of workers have been altered in order to protect the anonymity and confidentiality of respondents. Similar to the survey results, interviewees most often cited customers as the primary sources of sexual harassment in their workplace followed by co-workers and the occasional manger. Perpetrators were also often described as men and experiences with harassment ranged from verbal being the most common form experienced to explicit exposure and physical groping in the workplace. Verbal harassment experienced by workers was often in the context of customers repeatedly flirting with them or being “overly nice,” to the point where it made them uncomfortable during an interaction. Many of these experiences were shaped by their organization’s approach to sexual harassment as organizations are responsible for protective measures that influence a worker’s capacity to confront perpetrators in their work environment.This exploratory study sought to shed light on the issue of sexual harassment in retail store fronts of the cannabis industry as a newly legalized and emerging industry. Findings from this studied aligned with previous research documenting the high prevalence of sexual harassment in other retail and service sector industries .

Of the 117 study participants, 63, 68, and 46% reported experiencing at least one instance of sexist hostility, sexual hostility and unwanted sexual attention, respectively, in their place of work during the past 12 months. Although conducting a comparative analysis between the between prevalence of sexual harassment in cannabis dispensaries and other retail and service industries goes beyond the scope of this study, past literature on harassment in retail provides a reference point for responding to hypothesis one. For example, a study investigating sexual harassment in the restaurant industry found 50% of women and 47% of men experienced scary or unwanted sexual behavior while at work . While the two studies may vary in their methodologies and exact study population, they reach the same conclusion. Sexual harassment is an occupational hazard of retail and service sector industries. Therefore, a cursory comparison suggests harassment in the cannabis industry is equal, if not more prevalent than in other comparable industries. Studies regarding hazards of the retail and service sector industries also point towards customer sexual harassment as the specific context of harassment in retail fronts . The combined results of the multivariate analyses revealing gender identity to be a significant predictor of harassment, and the majority of perpetrators reported to be customers in this study highlights the harassment of women identifying bud tenders from customers as the specific workplace issue needing to be addressed. Furthermore, although only the bivariate analysis for sexual hostility revealed gender identity to be significantly associated with experiencing specific sub-scales of sexual harassment , results from the multivariate analysis,grow benches confirmed hypothesis 2a; gender identity is a significant predictor of all three sub-scales of harassment. Women were more likely to experience a greater frequency of harassment than the men in the workplace. This finding aligns with the literature on sexual harassment in the workplace, confirming women as the primary targets and victims of sexual harassment . These findings were also triangulated through interviews as sexual harassment was always discussed in the context of a female bud tender targeted by customers, co-workers and mangers alike. Only models one and two of the multivariate analyses alluded to hypothesis 2b regarding the racial and the ethnic differences in the likelihood to experience harassment. Model one predicting all form of sexual harassment and model 2 predicting sexist hostility indicated Black respondents experienced a greater frequency of harassment than White respondents. However, this finding was not supported by interview data as workers never revealed the race of the victims targeted for sexual harassment. This may be because they were not explicitly prompted to do so or because they did not believe the race of the victim to be a risk factor. For this particular thesis, the findings on race and ethnicity are inconclusive, however, future studies may seek to investigate how the actions taken to address sexual harassment may vary by the racial and ethnic background of the victim. We know from previous studies investigating sexual harassment that it is often enacted concurrently with racial harassment as a manifestation of power and dominance against minority groups .

Hypothesis 2c was confirmed through both bivariate and multivariate analysis, suggesting LGBQ individuals face substantially greater risks of experiencing sexual harassment in terms of both prevalence and frequency compared to heterosexual individuals. This finding is supported by past literature indicating sexual minorities are more likely to experience sexual harassment than their heterosexual counterparts throughout their lifetime . Although workplace protections for LGBQ individuals have increased in recent decades, this study, alongside others documenting discrimination, harassment and assault of the LGBQ community in work environments , demonstrates the continued need and obligation of employers to prevent the victimization of LGBQ workers. It should be noted that the interviews also did not reveal a connection between sexual orientation and sexual harassment as the primary goal of the interviews was to investigate organizational risk factors. Because previous studies have identified a relationship between workplace policies and the actions workers take to address sexual harassment , I investigated the possible linkage between a worker’s awareness of their employer’s policies to protect them from harassment and the likelihood to report such experiences. My prediction in hypothesis 3a of a negative relationship between the number of policies recalled and the likelihood to experience harassment was not supported by either bivariate or multivariate analysis. Quantitative analysis suggested there was no significant relationship between the number of policies recalled and the likelihood to experience harassment nor the frequency of harassment. However, qualitative results showed workers did feel workplace policies directly affected their likelihood to experience harassment while working. Specific policies described were policies on banning customers and how different stores decided to check the identification of customers which could leave workers in vulnerable positions if left alone with a customer. The conflicting results may be explained by a distinction between policies intended to shape retribution of harassment and policies that indirectly create opportunities for harassment to take place. The latter is more difficult to capture through surveys as the investigator has to have a preconceived notion of what to ask, thus highlighting the benefits of conducting mixed methods studies, particularly in new and understudied environments. In response to research question four, results from the qualitative interviews specifically highlighted tip systems and working in isolation as organizational risk factors for experiencing harassment. Tips in particular have previously been cited in occupational research as a risk factor for harassment as they incentivize workers to sexualize themselves and tolerate abuse from customers for their income . Responses by managers was a common theme discussed by workers as managers have the direct ability to ban customers based on inappropriate behavior and were often the first point-of-contact for workers to report an experience of harassment. The risk of continued harassment is exasperated by apathetic management teams who were described as prioritizing customer satisfaction over workers’ safety. Workers also illustrated the unique history of cannabis as a heavily sexualized industry whose legacy continues to permeate the industry today and negatively impact worker’s experience with sexual harassment. According to interviews, workers believed that customers either could not or refused to distinguish legally operating dispensaries from trap shops where women were explicitly used as props to sell product. The lack of distinction encourages the entitlement customers feel towards exploiting cannabis workers without repercussions. Interview results presented a paradox within the cannabis industry in which legalization introduced new protections to workers while simultaneously ushering in the corporate model of the “customer is always right,” which previous studies highlight as a detriment to the ability of workers to protect themselves from threatening customers . Furthermore, regarding research question five, data indicated workers were most interested in sexual harassment-based training for all workers, managers and supervisors as well establishing and publicizing clear policies on harassment. Findings from the survey were triangulated by interview results.

The project is led by Bonnie Halpern-Felsher, a professor of pediatrics at Stanford University and Mariaelena Gonzalez, assistant professor in public health at UC Merced. According to NCPC Director and UC Merced Associate Professor Anna Song, the researchers intend to provide data to counties that will allow them to make informed decisions about policy. Song notes that the counties in the study area are very different from, say, the Bay Area or Southern California, so state-level data isn’t adequate for formulation of local tobacco and cannabis policy. Song reports that the center’s work will fill gaps in knowledge about cannabis intake behavior; epidemio logical data is spotty, she says, because many people won’t admit to engaging in behavior that has historically been illegal and continues to be federally illegal. The researchers are also keen to understand the interconnections between tobacco and cannabis — emerging data indicates that perceptions of tobacco risk are related to perceptions of cannabis, and the relationship between the two may affect individuals’ future tobacco use. “These are the things we are trying to disentangle,” Song says. The center was founded with a $3.8 million grant from the Tobacco Related Disease Research Program, a state initiative administered by the UC Office of the President,rolling grow tables which dispenses funds derived from the Tobacco Tax Increase Initiative, a proposition approved by California voters in 2016.Cannabis institutes at three UC campuses in Southern California — UC San Diego, UC Irvine and UC Los Angeles — conduct research on the health effects and medical uses of cannabis and its derivatives. But they differ greatly in their approach. The UC Irvine program brings together medicine and law. The UCLA program has set itself the ambitious interdisciplinary task of exploring how cannabis affects society along the medical, legal, economic and social dimensions.

The UC Center for Medicinal Cannabis Research at UC San Diego, the oldest of the three institutes, was established when California Senate Bill 847 enabled UC to establish a program to “enhance understanding of the efficacy and adverse effects of marijuana as a pharma cological agent.” Today, the center’s cannabis research covers a broad range of clinical conditions such as neuropathic pain, autism, bipolar disorder and early psychosis — as well as public safety issues surrounding the use of cannabis and cannabinoids. A notable current CMCR study, authorized by the 2015 Medical Marijuana Regulation and Safety Act, seeks to better understand the effect on driving of THC. CMCR Director Igor Grant describes the study as “one of the first in the United States that looks in great detail into different dosages of THC and their ef fect on driving.” Each research day begins with study participants — already experienced with cannabis — entering driving simulators to undergo driving as sessments. Participants then consume THC in specified doses and continue over the course of the day to undergo driving assessments. Meanwhile, their bodily fluids are drawn over the course of several hours. The study seeks to determine how multiple dosing strengths of cannabis affect driving and for what duration driving impairment continues after cannabis use. The research also seeks to determine if saliva or breath tests can substitute for blood samples in determining cannabis intoxication and if sobriety tests administered with iPads can supplement standard field sobriety tests. The study is led by Thomas Marcotte, a professor of psychiatry at the UCSD School of Medicine. Another notable CMCR study, tentatively set to begin at the end of the summer, concerns autism. The research, which includes both a clinical trial and a basic science component, investigates the effect of CBD on severe autism spectrum disorder, a condition that affects one in every 68 U.S. children.

In the clinical trial — overseen by Doris Trauner, a professor of neurosciences and pediatrics at UCSD — researchers will ad minister oral doses of CBD or a placebo to 30 children who have been diagnosed with moderate to severe autism. CBD interacts with the endocannabinoid system, a network in the human body that regulates various physiological and cognitive processes. Researchers will attempt to determine whether CBD is safe for the study population to use, whether it addresses their symptoms, whether it alters neurotransmitters or improves brain connectivity, and if so, how. In the basic science component of the study, re searchers will use cells from the skin and blood of participants and, in Grant’s words, “re-engineer these cells to be neurons — to create little brain organoids, if you will.” This feat of re-engineering will allow researchers to observe how the cells function and, if CBD has benefited the subjects of the clinical trial, to investigate the associated mechanism of action. The study will be conducted with funding from the Wholistic Research and Education Foundation. Grant notes that Proposition 64 allocates $2 million annually to the CMCR. The center intends to use the funding partly to support its core facility and partly to fund small-scale pilot studies that might be conducted at the center itself, at other UC campuses or at campuses of other universities in California.Amuch newer entrant into medical cannabis re search is UC Irvine’s Center for the Study of Cannabis . As an interdisciplinary venture involving UC Irvine’s School of Medicine and School of Law, the center includes basic medical science, clinical science and jurisprudence in its purview. Daniele Piomelli, di rector of the center — as well as a professor of anatomy and neurobiology at the UC Irvine School of Medicine — calls cannabis “a quintessential multidisciplinary problem.” Because much existing cannabis law was written when medical knowledge about cannabis was scarce, he says, new knowledge to underpin new legislation is urgently needed. Piomelli further argues that because cannabis en compasses, for example, commercial and agricultural dimensions, researchers across disciplines must engage with each other to find realistic solutions to cannabis-related problems. “If medicine and science and law don’t talk to one another,” he says, “we’ll never have sensible legislation.”

In that spirit, the center has two directors — Piomelli representing the medical side of the interdisciplinary undertaking and Robert Solomon, a clinical professor of law at UC Irvine School of Law, representing the legal side. About 30 faculty members across law and medicine are involved in the center’s work. The centerpiece of the CSC’s work so far is an ongoing preclinical study called Impact of Cannabinoids Across the Lifespan. Piomelli, who directs the study while a team of UC Irvine principal investigators conducts the bulk of the research, characterizes it as a broad research project with many components, from which a stream of independent discoveries and publications is expected over the next 3 or 4 years. Piomelli reports that the study’s main purpose is to study THC’s effect on adolescents — and particularly on the adolescent brain. The human brain routinely produces neurotransmitters known as endocannabinoids — molecules, similar to cannabis derivatives, that are important in learning, memory and experiencing emotion. The key questions that the study addresses are these: Does exposure to THC, in a persistent way, change the brain’s endocannabinoid system? If so, what changes at the cellular and molecular level explain the alterations? Does exposure to THC during adolescence carry lasting implications for learning and emotion? The study has received a $9 million Center of Excellence Grant from the National Institute on Drug Abuse.Another new entrant into cannabis research is the UCLA Cannabis Research Initiative, founded in 2017 with a broad remit — “to understand how cannabis affects bodies, brains and society.” The initiative, encompassing an interdisciplinary team of 40 faculty members from 15 university departments, aims to function as an education, research and service organization that leads public discussions of cannabis, policy and health. The initiative got its start in the months before Proposition 64 was approved by voters. According to Jeffrey Chen, the initiative’s director, leadership at the Semel Institute for Neuroscience and Human Behavior anticipated that legalization would soon create the world’s largest market for recreational cannabis — and that California and particularly Los Angeles would “play an outsize role in establishing normative behaviors” around cannabis. Los Angeles, in Chen’s view,growing rack has become the world’s cannabis capital overnight. He and his colleagues hypothesize that, given the city’s status as a major tourist destination and an exporter of culture, “what happens in Los Angeles is very likely to be transmitted around the world.” So far, Chen says, the initiative’s research remains mainly oriented toward health-related issues. One study — soon to start, and led by Kate Wolitzky-Taylor, an assistant clinical professor in UCLA’s Department of Psychiatry and Bio-behavioral Sciences — seeks to develop and evaluate a behavioral treatment for young adults who exhibit cannabis use disorder and who use cannabis to cope with anxiety, depression and the like.

Cannabis, according to the researchers, is the most commonly used drug among young adults, and it can be harmful when its use qualifies as a “maladaptive way” of contending with negative experiences. Wolitzky-Taylor reports that the research project is a randomized clinical trial focusing on participants’ reactions to the anxiety and depression that might lead them to use cannabis. The treatment, she says, will draw on strategies such as “mindfulness, cognitive reappraisal skills, problem solving and … gradual exposure to distressing but objectively safe stimuli.” The treatment was developed in an iterative manner — an early version has already been tested with a small group of patients and further refinements may be made after the clinical trial is complete. The research is funded by a 3-year, $450,000 grant from the National Institute on Drug Abuse. Individuals with cannabis use disorder, if they are 18 to 25 years old, are encouraged to email the project’s coordinator, Nick Pistolesi , regarding participation in the study. A second example of the initiative’s work is de cidedly nonmedical. Brett Hollenbeck, an assistant professor of marketing at the UCLA Anderson School of Management, analyzed — along with Kosuke Uetake of Yale University — a large dataset of cannabis transactions in the state of Washington to learn about firm and consumer behavior in legal cannabis markets . Their goal was to provide policymakers, including in California, information useful for optimal development of cannabis taxation and regulation — optimal in the sense of maximizing tax revenues, safeguarding public health and discouraging a black market for cannabis. Washington created a legal framework for growing and selling cannabis in 2012. Legal sales began there in 2014. Since then, every cannabis transaction in the state has been recorded in an administrative dataset. The re searchers used the data to model consumer demand for cannabis products and measure price elasticity. Their analysis, covering the period from November 2014 to September 2017, indicates that Washington’s strict cap on cannabis retailers — some 550 are allowed in the entire state — has permitted retailers to command high prices and behave like local monopolies. The researchers report that when prices for regulated cannabis rise in Washington, consumers often switch to cheaper cannabis alternatives available from regulated retailers, rather than seeking out black market cannabis. Indeed, the researchers argue that Washington’s 37% sales tax rate for cannabis, though it appears high, does not drive down tax revenue, and in fact the state could generate higher revenue by raising the tax rate to 40% or higher. Further, the researchers calculate that Washington could substantially increase its revenue if it acted as the state’s sole cannabis retailer, as it did for alcohol sales until 2012, and could do so without causing an increase in cannabis prices.UC Riverside, though it has established no dedicated cannabis program, will soon host cannabis research for the first time. Nicholas DiPatrizio — a UC Riverside assistant professor in the School of Medicine’s Division of Biomedical Sciences who is newly equipped with a DEA Schedule I license — is set to begin re search investigating the effects of long-term cannabis use on metabolic diseases, including type 2 diabetes. DiPatrizio’s lab, using technologies such as tandem mass spectrometry, will study how cannabis use affects glucose homeostasis in wild-type mice — and will also investigate whether long-term cannabis use is sometimes associated with positive health outcomes such as increases in high density lipoproteins . DiPatrizio’s research has received more than $700,000 in funding from the Tobacco-Related Disease Research Program, the same entity that provides funding for the UC Nicotine and Cannabis Policy Center at UC Merced.