Hemp Growing

The information given by the total ion chromatogram is limited because of its complexity caused by co-elution and background noise. Instead, single ion chromatograms of different mass to charge ratios were extracted for isolating peaks ofindividual compounds, while avoiding co-elution and background noise. The stacked SIC of different thermal degradation compounds or aerosolized components from vaping aerosols of a) pure VEA, b) the mixture of VEA and extracted THC oil, c) extracted THC oil were shown in Figure 4.2. The black line represents the carbonyl/acids that can be generated from the thermal degradation of both VEA and extracted THC oil, the blue line represents the carbonyls/acids only from the thermal degradation of VEA, while the magenta line represents the thermal degradation carbonyls as well as cannabinoids only from the vaping aerosol of THC oil. Although the SICs were able to separate the co-eluting peaks with different m/z ratios, the isomers having identical m/z with similar structures and polarity are still not able to be separated or clearly identified. For example, multiple peaks are observed for C6H12O in the vaping aerosol of mixture of VEA and THC oil . While hexanal can be formed from terpenes, 97 4-methylpentanal could be formed from the thermal degradation VEA according to the proposed thermal degradation pathway in Scheme 4.1. However, since C6H12O is highly enhanced in the VEA aerosol , we assign the majority of this emission to 4-methylpentanal.Over 30 thermal degradation products from VEA were identified. All of the reported thermal degradation products from VEA are carbonyls/acids in this work, weed drying room consistent with other accounts. Riordan-Short et al. also identified several esters and alkanes with GC-MS .

While around 10 carbonyls and acids are identified both by us and Riordan-Short et al., carbonyls with VEA-specific structures have only been identified in this work. The lack of standard spectra for these VEA-derived compounds in GC-MS libraries may have prevented identification of peaks in the chromatograms of Riordan-Short et al.Moreover, some carbonyls identified by Riordan-Short et al. were not found in this work . The cause for discrepancy is unknown; however, we hypothesize it may be partially due to the difference in vaporization method .Many smaller thermal degradation carbonyls and acids appear to be formed by oxidation and bond cleavage of the aliphatic side-chain of VEA. The bond cleavage pathways for VEA degradation is proposed in Scheme 4.1. A proposed radical reaction mechanism is shown in Scheme 4.2. The thermal degradation reaction is initiated by H-abstraction by radicals such as OH, followed by the rapid reaction with O2 to form peroxy radicals . The peroxy radical can react with other RO2 to form carbonyls or alkoxy radicals. Alkoxy radicals may further react to form carbonyls , alcohols , and possibly alkenes . The primary thermaldegradation products may go through further oxidation steps and form more thermal degradation products . These RO2 –based mechanisms have been well studied and shown to be important in various chemical systems, like the atmosphere, biological redox, or fuel combustion. The relative peak intensity of carbonyls in Figure 4.2a support the proposed radical reaction mechanism in Scheme 4.2, since the most abundant peaks represented the formation of benzylic radical and tertiary radical formed in the first H-abstraction step which can be stabilized by the conjugation effect from benzene ring and positive hyper-conjugation effect from the adjacent C-H bonds. The proposed thermal degradation pathway is also supported by the detection of alkanes, including 2,6-dimethyl-1-heptene and 1-pristene, by Riordan-Short et al. and Mikheev et al., since these alkanes are generated in the proposed mechanism. Thus, our observations suggest that the C-C single bonds on the side-chain of VEA is easily oxidized and cleaved during the vaping process, which will cause the formation of a series of carbonyls that has VEA-specific structure, and also alkenes and alcohols.

These primary products may go through further thermal degradation process to generate secondary thermal degradation products like acids and dicarbonyls. Regarding products like duroquinone, durohydroquinone and ketene that have been identified previously by vaping or heating VEA we could not identified ketene as the it will form the same adduct molecular structure as acetic acid when reacting with 2,4-DNPH. We did not observe duroquinone for unknown reasons, possibly due to the difference in sample collection and methods of detection. Figure 4.2c shows the stacked SIC of vaping aerosol of THC oil. Besides thermal degradation carbonyl compounds, a large variety cannabinoids was also identified by HPLC-HRMS, since the phenolic hydroxyl group in cannabinoid structure is slightly acidic and can also be deprotonated in the negative mode of ESI. The thermal degradations products identified in the vaping aerosol of extracted THC oil may not only generated by THC, but can also from the thermal degradation of other cannabinoids, such as cannabinol , cannabidiol , cannabichromene , cannabigerol and corresponding acid , which have also been identified in the unvaped extracted THC oil. The mechanism of the production of carbonyls identified in the vaping aerosol of extracted THC oil may also involve the oxidation of the aliphatic side-chain followed by bond cleavage, since the main cannabinoids also have the side-chains with 5 carbons.Moreover, CBG may be the source of certain carbonyl products since it has a second side-chain with unsaturated bonds ; the specific mechanism is shown in Scheme 4.4. In contrast to VEA, the oxidation of CBG by OH proceeds through addition to the double bonds in the side chain instead of H-abstraction, consistent with the oxidation of other alkenes. The mechanism for the following steps are similar to the H-abstraction route.

The oxidation may also occur on the six member ring of cannabinoids such as THC can occur through pathways proposed in Scheme 4.3b and Scheme 4.5. For example, OH-initiated H-abstraction on THC can occur at the allylic site and OH-addition can occur at the endocyclic C=C, preferentially forming the tertiary alkyl radical. Then peroxy radical chemistry occurs through similar pathways as VEA, finally generating alcohols and potentially epoxides. Multiple SIC peaks are found at the m/z representing oxidized products of cannabinoids, suggesting a lot of different isomers exist. Our identification results are similar to those of Carbone et al., who utilized NMR for identification. Carbone et al. indicated peroxide products may also be formed during the oxidation process, a mechanism not shown in our schemes but would be consistent with RO2 chemistry. The oxidation products shown in Scheme 4.3b have the same number of carbons as THC; however, some thermal degradation products with different carbon numbers were also identified and are hard to trace back to precursor compounds. It is possible they may already exist in the original unvaped THC oil. Borille et al. found cannabinoid compounds or metabolites and 8 non-cannabinoid constituents in the extracts of cannabis plants by ESI-MS, with carbon number of cannabinoids range from C15 to C55. All molecular formulas of the THC oxidation products shown in Scheme 4.3b were also identified in cannabis extracts, suggesting that these components may already exist in the cannabis plant, and that oxidation from plant metabolism or during extraction couldhave occurred in addition to vaping. Moreover, the C19H28O3 has been identified as Cannabiglendol-C3 ; and there exist many possibilities for C23H34O4 ; C15H16O3/C15H18O3 had been identified as cannabispirenone/ cannabispiran. Some compounds in Table 4.1 still remains unidentified .Besides the oxidation products from vaping THC oil, for which the oxidation mechanism is described in Scheme 4.3, there remains unexplained formation pathway for the generation of some thermal degradation products . Couch et al. found the risk of exposure to VOC including diacetyl and 2,3-pentanedione during the decarboxylation and grinding process of dried cannabis material, but there is no clear mechanism given for their formation. The generation of these compounds may due to the thermal degradation of terpenes and terpenoids. Since there is still over 50% mass in the unvaped THC oil that remains uncharacterized, drying rack for weed it is likely that a portion of that mass are terpenes. Meehan-Atrash et al. identified degradation products from myrcene, limonene and linalool, including methacrolein, hydroxyacetone, methyl vinyl ketone. Tang et al. found 11 thermal degradation products from mixture of terpenoids, 7 of them are carbonyls including formaldehyde, acetaldehyde, acetone, acrolein, methacrolein, valeraldehyde and hexanal. These findings are consistent with the identification results in this work, illustrating that the extracted THC oil is a complex mixture, the complexity of which increases with thermal degradation chemistry. Further research on individual components is still needed for a better understanding on the whole picture of thermal degradation. For the mixture of THC oil and VEA, it is clear from the stacked SIC that the peaks shown in the chromatograph are mainly from aerosolization products of vaped THC oil instead of VEA. It is clear that the total signal from aerosolization products of the mixture is between that of vaping pure VEA and THC oil. Moreover, the oxidation of THC may also be suppressed by adding of VEA. While the signal ratio of cannabinoids in vaping aerosol of the mixture compared to unvaped THC oil is 0.34, the same ratio for oxidated cannabinoids in Scheme 4.3b is 0.22 .

THC was shown tohave a stronger tendency to degrade compared to VEA, since the boiling point for THC is 157 ˚C, while VEA start to decay at 240 ˚C without boiling. Table 4.2 shows the particle mass collected on the glass fiber filter at three temperatures and various e-liquid composition. It is clear that increasing temperature will increase the particle mass on the filter, which is consistent with expectations. However, the particle mass production is non-linearly suppressed with the addition of VEA compared to THC oil at the same temperature. The reason might be the formation of non-ideal solution with significant intermolecular interactions when VEA is added to the THC oil, as Lanzarotta et al.  had found that hydrogen bonding exists between the molecules of VEA and THC. Given the fact that THC has a much higher aerosolization rate compared to VEA , the cartridge may be enriched in VEA since vaping continues until it is 100% VEA. In order to figure out the influence of VEA to the formation of carbonyls, it is informative to normalize the mass of carbonyls by the particle mass collected at the same temperature . While e-cigarette users who used nicotine products will self-titrate nicotine intake in daily use, there is also evidence that people who use higher potency cannabis for recreational purpose can titrate their THC dose. Figure 4.4 shows the normalized mass of 9 thermal degradation carbonyl compounds by particle mass produced from vaping VEA, THC oil and their mixture at 455 ± 10 °F . Within the C4 – C6 carbonyls shown in Figure 4.4, butyraldehyde, valeraldehyde, hexanal are thought to be from the thermal degradation of cannabinoids and terpenes , supported by Tang et al., while isobutyraldehyde, isovaleraldehyde and 4-methylpentanal are from the thermal degradation of VEA , supported by RiordanShort et al. Since some isomers can’t be separated in this work, we discuss the pair of isomers together. From the normalized carbonyl concentration, it is clear that certain carbonyls such as formaldehyde, hexanal/4-methylpentanal, glyoxal, diacetyl/3-oxobutanal are produced in much higher abundance from VEA compared to extracted THC oil. Although some products like formaldehyde can be produced from both VEA and THC, the production of formaldehyde from VEA is more favorable since it involves a tertiary radical intermediate in the first step , which is more stable than the secondary radicals formed from the side-chain of THC. The proposed chemistry is, thus, consistent with higher formaldehyde formation by VEA. The same explanation can also apply to the generation of 4-methylpentanal, which only comes from VEA and thus likely dominates the distribution of the isomer pair over hexanal. The formation of glyoxal, diacetyl and 3-oxobutanal from VEA likewise may be enhanced compared to THC due to higher stability of radical intermediates. Diacetyl is thought to be byproducts of cannabis plants,61 and there is no clear indication of formation of diacetyl from VEA . The formation of its isomer 3-oxobutanal can be expected from VEA, however. The corresponding SIC of diacetyl shows that multiple peaks exists in the vaping aerosol of extracted THC oil, but only one peak shown in the vaping aerosol of pure VEA, suggesting that cannabinoids and terpenes may generate multiple isomers which have the same m/z as diacetyl, but VEA propably generates only 3-oxobutanal.

In addition to thermal degradation products, flavoring chemicals are also found to be significant components in e-cigarette aerosol. Allen et al. 53 measured the concentration of diacetyl , 2,3-pentanedione , and acetoin in 51 e-cigarettes from different brands and flavors, with the highest concentrations found for e-liquid flavors such as “Peach Schnapps.” In this work, the estimated concentrations of the flavoring chemicals diacetyl , 2,3-pentanedione , and acetoin are fairly consistent with some measurements for the Classic Tobacco flavor but higher than others. Of note is that Klager et al. found diacetyl concentration in 16 different e-cigarettes varies from 0.028 – 3.69 µg/m3 , while our results show a concentration of 56 ±15 µg/m3 . It is clear that the amount of flavoring chemicals largely depend on the individual e-liquids, puffing regimen, and collection methods. In addition, two carbonyl flavoring additives have been quantified here for the first time in ecigarette aerosol. Acid additives are used to control the acidity of eliquids. Inhaling either diacetyl, or the related flavoring 2,3-pentanedione, has been associated with bronchiolitis obliterans . As the composition of e-cigarette aerosol is complex and the range of products is vast, a more systematic understanding of the fundamental chemistry is needed.Electronic cigarettes are battery-operated devices used to “vape” or aerosolize “e-liquid” consisting of propylene glycol , vegetable glycerin , nicotine, and optional flavor compounds. The global market share of e-cigarettes is rapidly growing, and e-cigarette use among young people has become a significant public health concern. Of U.S. high school students and middle school students, 27.5% and 10.5%, respectively, self-reported usage for one or more days during the past 30 days in 2019. The design of the e-cigarette has rapidly evolved from 1st generation “cig-a-like” pods with disposable, prefilled, curing cannabis e-liquid cartridges and fixed operational parameters , to 3rd generation “mods” with a refillable e-liquid tank and adjustable device operational parameters.

More recently, 4th generation“mod-pod” hybrids with fixed power output have been released. E-cigarettes gas and particle emissions are composed of aerosolized PG, VG, optional flavors, and nicotine from the e-liquid, as well as free radicals, and a variety of carbonyls or hydroxycarbonyls formed by thermal degradation during the e-liquid heating process. Recent evidence suggests hydroxycarbonyls may be more abundant than anticipated, but their impacts on health remain poorly understood. With the ability to change vaping parameters , coil material, and e-liquid formulations in 3rd and 4th generation devices, there exists a multitude of use combinations that can influence the composition of the inhaled e-cigarette aerosol. In particular, aerosol composition and gas/particle partitioning could greatly influence the risk of chemical exposure and aerosol deposition in the human respiratory tract. However, the ways in which e-liquids form aerosol components under different vaping parameters have not been fully elucidated in the literature. Coil temperature and e-liquid composition will directly affect e-cigarette aerosol emissions, as heating e-liquid solutions with metal coils results in thermal degradation reactions and changes in aerosol concentration. The majority of published studies have correlated e-cigarette emissions to device voltage and power, but not directly to the vaping coil temperature that governs the thermal degradation process. For example, Korzun et al. inferred coil temperature by airflow rate, and found higher temperatures led to higher concentrations of formaldehyde and acetaldehyde by promoting the degradation of higher molecular-weight products such as hydroxyacetone and glycoaldehyde in the product mixture.

Uchiyama et al. evaluated the phase distribution for a number of compounds, and found the formation of degradation products from vaping exponentially increased when the device power exceeded 40 W. However, a direct comparison between such studies is challenging. This is because the actual coil temperature is synergistically influenced by many factors, some of which are inherent to the coil, while others are a result of the conditions of operation. For example, different coils may have different resistances due to material and structural variance. Furthermore, coil temperature may also be influenced by e-liquid composition, which changes the viscosity and heat capacity, or by air flow rates in the device, as faster air flow rates have higher cooling effects. Thus, a single vaping device may produce different temperature ranges for the same voltage input upon minor alterations in operational scenarios.In addition, the aerosol emissions will change as a result of the users’ puffing regimen. Bitzer et al. showed puff volume and duration influence the per-puff yield of nicotine, carbonyls, aerosols, and free radicals. Beauval et al. also found modifications in puffing conditions lead to significant variations in the carbonyl composition of e-cigarette aerosols.However, there remain a number of questions concerning the fractions of PG and VG in the total e-liquid that convert to degradation products, the specific chemical mechanisms of transformation, and the ways in which e-cigarette chemical components partition between phases in response to changing vaping parameters.Thus, a systematic understanding of how the carbon mass balance and chemistry of the vaping process respond to changing e-liquid formulation, major puffing parameters, and actual coil temperatures is critically needed. Monitoring coil temperature instead of voltage/power as a standard evaluation metric may provide greater fundamental insights into the chemistry.

However to do so, the coil temperature will need to be directly measured during each puff, as the temperature-controlled programs of e-cigarette devices may not be a true reflection of the actual coil temperature. In the present study, a broad chemical analysis suite, volatility-based aerosol sampling, and direct measurement of coil temperatures were employed to study the aerosol emissions from a 3rd generation e-cigarette device at various coil temperatures, puff durations, and PG:VG ratios in the e-liquid solution. Flavoring compounds were deferred for future research. The loss of mass from the e-liquid conversion to aerosols was compared with independent measurements in the particle and gas phases for carbon mass closure analyses.E-cigarette aerosols were generated using a 3rd generation Evolv DNA 75 Color modular vaping device with replacement single mesh vaping coils that have a coil resistance of ca. 0.12 Ohm. The stainless steel coil was selected as only limited coil materials are appropriate for temperature control. The device has a rechargeable battery with a variable output voltage and power , an atomizer coil assembly, a refillable e-liquid tank that enables eliquid with variable formulations to be tested, and a push button to initiate puffing. The device was robotically operated by a custom linear actuator during the puffing proces s, which enabled precise control of the puff rate and puff duration with a ±3% standard deviation . Evolv Escribe software was used to set the power and temperature conditions to achieve the desired coil temperature , as measured by a flexible Kapton-insulated K type thermocouple in contact with the center of the coil surface, cannabis dryer and output to a digital readout. The puff flow rate was 1.186 ± 0.002 L/min, and the corresponding puff volume for a 3-s puff was 59.3 ± 0.1 mL, as quantified by a primary flow calibrator . The puff volume and duration selected for this study is consistent with the CORESTA e-cigarette testing protocol .

However, puff volume larger than 100 mL and puff duration longer than 3 s have been observed in some vaping scenarios. For example, Robinson et al. found a typical case of puff topography with 3.7 s puff duration and 144 mL puff volume. Thus, this highlights a limitation of the current study when extrapolated to various vaping scenarios, as an increase in the puff volume will increase the formation of aerosol and thermal degradation compounds.167 The puffing protocol for the puff duration study is not based on volume, but used a variable puff duration at a fixed flow rate. Table 3.1 shows the experimental conditions used in this work. Pure VG, PG, and nicotine were used to generate e-liquids at the ratios and concentrations shown in Table 3.1. Particles were collected on a hydrophilic polytetrafluoroethylene membrane filters . PTFE and other types of filters have been used in sample collection for e-cigarette research. As hydrophobic filters were found to be incompatible with the polar compounds in e-cigarette aerosol, the hydrophilic PTFE filters were chosen for use because they have broad compatibility with both polar and non-polar functional groups. Both the gas phase of total aerosol stream and the particle filters were analyzed for mass and chemical composition. The total mass lost from the e-liquid due to vaping was determined gravimetrically on a microbalance by weighing the e-liquid compartment immediately before and after puffing 10 puffs, and dividing by the number of puffs at different experimental conditions. The standard deviation of the gravimetric analysis after triplicate measurements was determined to be ~ 20%, mainly due to variations in puffing. The composition of gas phase PG/VG, was analyzed by chemical ionization triple-quadrupole mass spectrometer ; a detailed description can be found in Section 3.2.4. The particle mass on the filter was analyzed after each collection on the microbalance, also performed in triplicate. The total mass of molecules residingin the gas phase was determined as the difference between the total mass of e-liquid lost and the mass of the particles collected.E-cigarette aerosols are known to be semivolatile at room-temperature, i.e., the chemicals can exist in both gas and particle phases under various conditions , and are highly unstable mixtures that undergo continuously change of size, number concentration and chemical composition by coagulation, evaporation/condensation of individual components, wall deposition and potentially water uptake. Thus, there is no perfect sampling protocol for such a dynamic mixture. Sampling with particle filters may either underestimate or overestimate total non-volatiles. Underestimation may occur if fine particles break through the filter. Overestimation could result if the filter has a higher surface area than in realistic vaping scenarios, or if the filter is saturated with an organic film, into which the semivolatiles can partition during sampling. Our particle size distribution analysis with a scanning mobility particle sizer that measures a size range of 0.014 – 0.671 µm diameter showed that particle breakthrough for Omnipore filter at a 0.2-µm pore size may not be significant for this work. However, the diameter of aerosol will go through a size change process caused mainly by coagulation and evaporation that could occur during the aerosol collection and measurement steps. Zhang et al.231 found that the count median diameter of e-cigarette aerosols is 120 – 180 nm when counted immediately after emission from the e-cigarette. The CMD changes to 400 nm for the measurement of droplets at steady-state. Furthermore, we confirmed that the collection efficiency for the filter was > 97.5% based on consecutive collections in series. Thus, we believe this method minimized the possible underestimations of the particle phase. We then tested a denser structure or higher surface area particle filtering material. A high-flow High Efficiency Particulate-free Air capsule upstream of our chemical analyses removed 99.9% of all particles . However, the HEPA capsule also removed 50-100% of gaseous formaldehyde, hydroxyacetone, acetone, acetaldehyde, and dihydroxyacetone gas standards that were evaporated and diluted directly into a 100-L Teflon FEP bag using chemical standards, which would overestimate the particle phase. For the purpose of this work, particles that are trapped by hydrophilic PTFE filter are termed the “nonvolatile ” or “particle” fraction and the difference between the total aerosol and the NV fraction is termed the “volatile/semivolatile” or “gas” fraction. Although particles are termed nonvolatile, it does not mean that they cannot partition to the gas phase under conditions different than the ones we tested . Likewise, semivolatiles emitted in the gasphase directly from the mainstream can condense onto surfaces that have higher condensable surface area than used our study.The particle filters were analyzed by an Agilent 6890N gas chromatograph coupled to an Agilent 5973N quadrupole mass spectrometer . Filters were extracted by a 10-mL 1:1 mix of methanol and ethyl acetate . The method for the analysis of PG, VG, and nicotine was adapted from Williams et al.232 The components were separated on a DB–wax capillary column with ultra-high purity grade Helium at a constant flow of 1.1 mL/min. The temperature program was 50 °C , 8 °C /min to 160 °C, 5 °C /min to 170 °C, then 170 °C . Electron impact mass spectra for PG, VG, and nicotine were > 90% matched to the National Institute of Standards and Technology database. PG, VG, and nicotine standards were used for GCMS calibration.

Milwaukee’s urban agriculture organizations have worked to secure longer leases for community gardens, but they have not succeeded in purchasing and preserving many of the sites, so most of the city’s gardens remain vulnerable to development. The gardens that exist today are generally clustered around the Near North Side, where poverty, unemployment, and food insecurity are high and development pressure has remained low. Based on the demographics of the Near North Side, the people most likely encounter the city’s gardens are low-income Black residents, however my spatial analysis revealed that gardens associated with citywide programs are also relatively more accessible for neighborhoods with higher rates of Hispanic and Asian/Pacific Islander residents than for neighborhoods that are largely white. These gardens appear to be concentrated where the greatest economic need is, but if development pressure in the disinvested neighborhoods were to increase, the gardens will be vulnerable to displacement. In Philadelphia, development pressure has increased quite dramatically in some neighborhoods, displacing gardens and residents alike. PHS’s effort to concentrate greening interventions in specific neighborhoods has proven the revitalization potential of urban agriculture. However, this revitalization focus seems to limit the benefits for the city’s poorest residents. Based on my spatial analysis, the program’s gardens are likely to be closer to neighborhoods with lower poverty rates and higher housing costs . Neighborhoods with more Black and Hispanic residents are more likely to have a garden nearby, cannabis growing equipment but the racial composition of many neighborhoods has also been in flux as property values rise, and Black residents appear to be gradually losing access to gardens in this process.

In Seattle, through the concerted effort of P-Patch program and nonprofit leaders seeking to maintain the program’s legitimacy, gardens have become more accessible for the city’s low-income communities over time. However, they have also become less accessible for immigrants, reflecting a pattern in all three cities where many foreign born residents seem to lack convenient access to programmatic gardens. Moreover, in Seattle the increasing access for high-poverty neighborhoods belies the fact that many people in poverty have been forced out of the city altogether, as property values have risen precipitously in recent years due to Seattle’s status as a world-class creative city—a reputation bolstered by the secure, widespread presence of P-Patch gardens. Thus, someone encountering a garden in Seattle today is more likely to have a high income, and while they might appreciate the social, environmental and aesthetic benefits of the garden before them, there are thousands of other people missing out on that experience because of the city’s changing economic condition. The individuals moving through the socio-environments in these three cities are unlikely to directly see the organizations that have helped to build and protect the city’s cultivated spaces, but as this dissertation shows, organizations in all cases have clearly played a role in shaping the flows of materials, ideas and people that converge to make urban agriculture and urban life more broadly. Electronic cigarettes , sometimes referred as “e-cigs”, “e-hookahs,” “vape pens,” and “electronic nicotine delivery systems ”, are rechargeable electronic nicotine delivery devices that are alternatives to smoking tobacco cigarettes. E-cigarettes consist of four parts: an atomizer , a battery, an e-liquid reservoir and an electronic control system. The atomizer heats and aerosolizes the e-liquid during the “vaping” process when the user takes a puff or presses the button; this generates a nicotine-containing e-cigarette aerosol that will be inhaled by the user for the purpose of nicotine intake.

Unlike traditional tobacco products, there is no combustion in the use of e-cigarettes, which eliminates the intake of tar and other harmful and potential harmful chemicals generated through cigarette or cigar smoking. In addition, the tar generated through conventional smoking which is extremely toxic to human and damages the smoker’s lungs through biochemical and mechanical process over a long time period 7-9 can also be eliminated through e-cigarette use. To date, e-cigarettes have been widely regarded as a “less harm” alternative to traditional cigarettes that can be used to help smoking cessation. However, the controversy of e-cigarette use has been increasing in recent years, since the beneficial link between e-cigarettes and smoking cessation is debated and emerging health issues had been found, related to the use of different kinds of e-cigarettes. It is noteworthy that thermal degradation products have been characterized due to the vaping process, some of which are known to have negative human health effects. The development of a nicotine aerosol generation device started in 1963, while the modern ecigarette was invented by a Chinese pharmacist Han Li, who thought of vaporizing nicotine containing propylene glycol using a high frequency ultrasound-emitting element, causing a smoke like vapor. E-cigarettes was first introduced to Chinese market starting from 2004, then entered the European and the US market in 2006 and 2007. The later design of the e-cigarette has changed from the earlier ultrasonic vaporization method to a battery-operated heating element. E-cigarette device design has evolved significantly since its introduction. The first-generation e-cigarettes use fixed and low voltage batteries, with a physical appearance similar to combustible cigarettes and are often referred to as “cig-a-like”. There exist two versions of the first-generation e-cigarette on the market, one is a two-part design, in which the replaceable atomizer and e-liquid reservoir are in one part, while the battery is separated in another part. The second style combines the atomizing unit, e-liquid reservoir and battery into one part. The first-generation product is still widely sold on the market. The second-generation e-cigarette typically has a larger variable voltage battery with a device referred to as a “clearomizer”. It has a removable atomizing unit with a filament, separated into a e-liquid reservoir and battery. The e-liquid tank of the second generation device has a larger volume reservoir compared to first generation systems, and can be refilled with different e-liquids. The third-generation e-cigarette, known as the “Mod”, has modified batteries that is able to vary the device power, voltage and, thus, temperature. It has a removable atomizing unit and larger e-liquid tank compared to the original clearomizers. 

The Sub-Ohm tank with low resistance coils in atomizers is highly customized, as it is designed to create a large cloud with a strong delivery of nicotine and other additives. Stainless steel, nickel and titanium are typical materials used for the coil in third-generation devices, as these materials enable linear temperature changes with the adjustment of device power output. The fourth-generation e-cigarette is referred to as “Pod-Mods”, and contains a prefilled or refillable “pod” cartridge with a modifiable system. The compatible prefilled pod cartridges usually contain nicotine with PG/VG, THC or CBD as oils, and flavoring compounds. In addition to e-cigarettes, an inhalation device called a “vaporizer” is also available on the market; it applies non-combustion heat to aerosolize dry herbs or oil to release the active substance in these materials without combustion. Moreover, “dabbing” or “dibbing” is a specific term that describes the action or practice of inhaling small quantities of a concentrated and vaporized drug, cannabis drying trays typically cannabis oil or resin. It usually simulates the aerosolization process by placing the extracted THC oil concentrates on a hot surface. Since its first commercial introduction to the United States, sales in the e-cigarette industry has increased to $3.5 billion by 2015. The e-cigarette industry has greatly impacted the use of new tobacco products among youth. The prevalence of e-cigarette use among high school students increased from 1.5% in 2011 to 16% in 2015, which surpasses the prevalence of conventional cigarette use among high school students. According to a report by the Centers for Disease Control and Prevention in 2020, 19.6% of high school students and 4.7% of middle school students reported current e-cigarette use. Among current e-cigarette users, 38.9% of high school students and 20.0% of middle school students have used e-cigarettes on 20 or more of the past 30 days; 22.5% of high school users and 9.4% of middle school users reported daily use. Among all current e-cigarette users, 82.9% used flavored e-cigarettes. Investigators conducting toxicology and human health studies of acute and chronic use of e-cigarettes are struggling to keep pace with e-cigarettes’ popularity and product changes. The study of the health effects of these products is complicated by the fact that there are hundreds of e-cigarette devices and thousands of commercially-available e-liquids available to consumers. Further, the new generations of e-cigarettes have increased the flexibility of use for consumers by allowing any e-liquid to be added to the tank and a large range of variable power settings, which can increase the temperature of the device, as well as the output of vapor/aerosol and delivery of nicotine.

The composition of typical regular e-liquid for nicotine delivery usually include propylene glycol , vegetable glycerin , water, nicotine, and flavoring additives. PG and VG are typically used as solvents in order to produce an aerosol that simulates cigarette smoke. PG is a transparent and viscous liquid at room temperature with a sweet taste. It has very low volatility with a boiling point of 188 °C. The use of PG is generally regarded as safe for oral consumption, and it is usually used as a humectant and preservative in food, tobacco and the personal care industry. Moreover, PG is also used in the pharmaceutical industry as a solvent for drug delivery. Although it is widely used, the toxicology at a high concentration is increasingly recognized and recently reported. VG is a colorless and odorless viscous liquid with a boiling point of 290 ℃. It also has low volatility and a sweet taste, serving as a humectant, solvent, and sweetener in food, pharmaceutical and personal care applications. Both PG and VG have multiple hydroxyl groups,which results in the strong intermolecular force in the e-liquid and e-cigarette aerosol by forming multiple hydrogen bonds. Vaporization of PG and VG requires a relatively high temperature, although PG and VG start decomposing within the temperature range of e-cigarette use. The ratio of PG and VG in e-liquid varies in different products based on whether flavor or more aerosol mass or “cloud” is desired, while the most common two ratios are 50% PG/50%VG and 70%VG/30%PG. E-liquids containing more PG delivered more nicotine to these e-cigarette users. The chemical structure of PG and VG are shown in Scheme 1.1a. Nicotine is a chiral alkaloid produced in the nightshade family of plants, which has been widely used as recreational or anxiolytic compounds. Nicotine is a highly addictive compound that acts as receptor agonist for nicotinic acetylcholine receptors; its binding strength is better than the neurotransmitter acetylcholine. Therefore, nicotine is the equivalent to an increase in the amount of neurotransmitters, which results in increased secretion of dopamine from the reward center of the human brain. The average amount of absorbed nicotine per cigarette is about 2 mg, while the nicotine content of commercially available e-liquids varies from low to high . The chemical structure of nicotine is shown in Scheme 1.1b. Beside PG, VG and nicotine, most e-liquids contain flavor chemicals that have been certified as safe for ingestion in the food industry. The use of flavor compounds to create various flavor combinations is attractive to consumers. There are various chemical families of flavorants used on the market, including aldehyde , ketone , alcohol , monoterpene and ester . Animportant category is aldehyde, which has been recognized as “primary irritants” of the mucosal tissue of the respiratory tract. Behar et al. has identified that the most commonly used flavoring chemicals are menthone, p-anisaldehyde, menthol, cinnaldehyde, vanillin, and ethyl maltol, which has been found in 41 – 80% of commercial e-liquids. The transfer of these flavoring chemicals from e-liquid to e-cigarette aerosol is very efficient , while it has also been found that the refilled fluids that have lower concentrations of flavoring chemicals exhibit lower cytotoxicity, suggesting the toxicity of the e-cigarette aerosol is related to the concentration of theflavoring chemicals. However, with the significant increase in the array of different e-liquid products, it is difficult to comprehensively characterize all flavor compounds on the market. Previous research found flavor chemicals to be 1-4% of the total e-liquid volume, although the concentration of some specific flavor chemicals were sufficiently high enough to possibly be of concern for inhalation toxicology. Some specific flavoring chemicals like diacetyl has been found to cause adverse health effects to e-cigarette users, even if they are safe to digest.

Assessing the socio-demographic dynamics of urban agriculture development in New York City, Reynolds notes that while low-income communities, immigrants and people of color often bring significant knowledge, energy and enthusiasm to the development and maintenance of gardens, these groups tend to have less access to the resources, networks and cultural capital required to build and defend community gardens in the urban landscape. As earlier chapters have demonstrated, in order to attract resources and legal status for their gardens, community garden programs must legitimize themselves according to some of urban agriculture’s potential benefits at the expense of others. In all three cities, urban agriculture advocates have made claims about the role of gardens in helping people in need, but they have also emphasized arguments about the economic benefits of community gardens. Economic benefits like neighborhood development and elevated property values can be in tension with serving the needs of the marginalized, whose interests are often left behind in the flow of capital through cities . On the one hand, community gardens may be easier to establish where vacant land is more abundant, that is, in neighborhoods with depressed property values—often those with higher proportions of people in poverty, immigrants, and/or residents of color. On the other hand, marginalized communities may have a harder time marshalling the resources needed to defend community gardens from rising property values and increased neighborhood development, if and when these potential economic benefits of urban agriculture materialize. This tension is ubiquitous in urban agriculture . However, ebb and flow flood table researchers have to date paid little attention to the role that citywide community gardening organizations can play in mitigating neighborhood inequalities by amassing and equitably distributing the resources needed to build, maintain, and defend urban agricultural spaces.

In this chapter, I draw on historical datasets developed from review of organizational documents for each city to conduct a longitudinal spatial analysis of garden accessibility. To fully understand who is benefitting most from community gardens, multiple types of data ought to be considered. Ethnographic research or extensive surveys would be needed to determine who is actually using the gardens within a program, how much nutritional, recreational, social and cultural benefit participants are receiving, and what collective benefits the local community is realizing from the presence of a garden. With the exception of a few documents summarizing survey results from Seattle’s P-Patches in the 1990s, my data do not provide this type of detail about usage or measured outcomes. However, extensive review of the historical documents from each program does enable another important approach to understanding equity in garden access: the proximity of gardens to different neighborhoods. Mapping the gardens that each program invested in over time and using spatial analysis to assess the gardens’ accessibility to marginalized communities, we can understand the historical trajectory of each program’s impact on the urban environment, a perspective that would not be possible with ethnographic or cross-sectional survey methods. A spatial approach is especially relevant for understanding urban agriculture as a land use as well as a social practice. Urban researchers have used spatial analysis to assess whether community gardens are alleviating food deserts and to identify the neighborhoods in a city which would benefit most from urban agriculture , but have yet to analyze the extent to which existing community gardens in a city actually serve the neighborhoods with the highest need.

In this chapter, I first summarize the methodology used to map the gardens in each city over time. Then, I describe the results of my spatial analysis in detail, connecting them to key points from the qualitative historical analysis laid out in preceding chapters. I conclude by highlighting the ways that organizational decisions over time are evident in how gardens are and have been distributed across each city.In order to show how the citywide gardening programs in Milwaukee, Philadelphia and Seattle have expanded over time and how accessible their gardens have been to marginalized communities, I built an original historical dataset2 , mapped the gardens that were associated with each program in 1980, 1990, 2000, 2010, and 2019, and conducted a series of spatial analyses on the relationships between garden locations and neighborhood demographic characteristics. During my review of documents from the main garden programs in each city, I compiled a database with the name, location, and years active for each garden mentioned over the programs’ histories. Records such as annual reports and garden maps tended to provide complete snapshots of the gardens included in a program at a particular time, while newsletters and newspaper articles offered supplementary information to date the creation or closure of some gardens. Together, the documents available for each city furnished enough information for a detailed, if not perfectly complete, picture of how the programs expanded in urban space as their budgets grew and they were able to develop new gardens—and how and where the programs contracted under the pressure of changing budgetary or real estate market conditions.In order to understand the relative accessibility of each programs’ gardens for marginalized groups, I acquired neighborhood demographic information for each city at the Census tract level. Using Geolytics, I downloaded a dataset with relevant variables for 1980, 1990, 2000, and 2010 fit to the 2010 Census boundaries. Using the software program R, I then downloaded equivalent values from the 2015-2019 American Community Survey . Given the salience of urban agriculture’s potential benefits for immigrants, low-income and people of color, I obtained counts and calculated percentages for each tract’s poverty rate, percent foreign born, percent nonHispanic white, percent non-Hispanic Black, percent Hispanic, and percent non-Hispanic Asian or Pacific Islander.

Census questions about racial and ethnic categories have changed slightly over the last 50 years, and the groups above were chosen for this study because they can be calculated consistently across the 5 decades of interest while speaking to the patterns of racial inequality and marginalization most commonly observed in US cities. Because the ability to create, maintain and preserve community gardens is influenced by socioeconomic characteristics such as real estate values and supporters’ cultural capital, I also obtained tractlevel data on education levels , median household income, and median monthly housing costs. After compiling a dataset with the independent variables of interest for the 2010 Census tracts across all 5 decades, I calculated measures of garden accessibility for each Census tract in each decade. I used the Google API to geocode the garden addresses into latitude and longitude, and then georeferenced the coordinates to align with the Census tract coordinate reference system. Overlaying the gardens’ geographic information onto the 2010 Census tracts, I obtained counts for the number of gardens in each tract in 1980, 1990, 2000, 2010 and 2019. Since most tracts had zero gardens and very few had more than one, this measure had significant skew; I then created a binary variable indicating whether a tract contained at least one garden in a given year. There is a great deal of variation in the size of Census tracts, hydroponic drain table and the boundaries between tracts do not represent firm restrictions on residents’ activities. To address these concerns, I created additional dependent variables based on distance rather than tract boundaries. For each tract and year, I calculated the distance from the tract centroid to the nearest garden, and I created another binary variable indicating whether at least one garden was within a one-mile radius of the tract centroid. Before mapping and modeling garden accessibility, I conducted exploratory data analysis to refine my variable specification. I ran correlations of all variables and found several strong correlations that risked weakening the models through multicollinearity. First, the two variables for education were strongly negatively correlated. I chose to model percent with a college degree and leave out percent with less than a high school education, given the role of cultural capital in successful creation and preservation of community gardens that earlier studies have identified . Next, median household income was strongly positively correlated with housing costs and strongly negatively correlated with poverty rates, but the correlation between housing costs and poverty rates tended to be much weaker. I chose to include housing costs and poverty rates in the models while removing household income to reduce multicollinearity.

Retaining the poverty and housing variables, both the accessibility of gardens for low-income communities and the threat to gardens from high land values can be represented in the model. Due to a consistently strong negative correlation between percent white and percent Black, I chose to remove percent white from the models and retain focus on gardens’ proximity to people of color. I also found strong positive correlations between percent foreign born and percent Hispanic in Milwaukee and Philadelphia, and between percent foreign born and percent Asian or Pacific Islander in Seattle. Due to the theoretical importance of understanding garden accessibility both for racial minorities and for immigrants, I chose to retain all three variables in my models and test the outcomes when each of them was removed to see if multicollinearity was impacting the results.After testing for multicollinearity, I tested for spatial autocorrelation—that is, whether high or low values for any of the variables were clustered in adjacent Census tracts. For each city, I made three matrices defining neighboring tracts: queen contiguity, 2-nearest, and 3- nearest neighbor weights matrices. Then I calculated Moran’s I for all variables in each city and year, using each of the three neighbor weights matrices. Regardless of the matrix used, Moran’s I values were greater than 0.3 for almost all of the independent variables, indicating substantial spatial autocorrelation. In other words, neighborhoods show clustering in characteristics such as poverty rates, racial and ethnic composition, and education levels. This finding is unsurprising, given what we know of neighborhood effects and the legacies of residential racial segregation, yet it is important to note due to its potential impact on any spatial models. For all cities, years, and neighbor weights matrices, Moran’s I showed significant spatial autocorrelation in the distance based measures of garden accessibility . However, the tract-boundary measures of garden access had Moran’s I values close to 0 in Milwaukee and Seattle for all years, indicating that the gardens themselves are not generally clustered in these cities. Only Philadelphia appeared to have statistically significant clustering in the locations of gardens. Mapping the dependent variables for each city and year showed that much of the clustering in the distance-based measures of garden accessibility was due to a complete lack of gardens in certain areas of the city, where adjacent tracts logged progressively larger distances to the nearest garden. Figure 1 illustrates the typical appearance of this pattern, with the areas of northwest and south Milwaukee and northeast and south Philadelphia hosting zero gardens from their cities’ respective garden programs. The clustering of distance-based garden accessibility variables in Seattle is not as visible when mapped, but it nonetheless registered as significant in the Moran’s I tests for all neighbor weights matrices and years.Given that garden programs are working to administer multiple sites across a city with limited resources, the lack of gardens in far-flung regions may be understandable. Still, when large areas of a city remain unserved by a citywide program, the lack of service to these areas is notable. For this reason, I chose not to treat the far-flung tracts as “outliers” and remove them from the models altogether. However, in practical terms, the progressively larger distances to the nearest garden that result from this pattern can skew the dependent variable in a way that interferes with the overall model fit and accuracy. Therefore, I developed a “corrective” variable giving the distance from each tract centroid to City Hall, a measure approximating the resources required to travel to the tract from garden program offices5 . I chose to run models with and without distance to downtown in order to assess how well it corrected for skew from the far-flung tract values and whether it impacted results in any other way.Given the potential impact of multicollinearity and spatial autocorrelation on regression modeling, I ran a series of Ordinary Least Squares regressions and diagnostics to test the impact of controlling for distance to downtown, to assess the influence of correlations between race and immigration variables, and to determine whether OLS or spatial models would be more accurate.

These elements of urban political economy can be seen as the municipal government’s own organizational environment, which the government and its representatives must attend to in order to maintain their legitimacy, resource flows, and survival. Whether in pursuit of land tenure for community gardens or other public investments in quality of life, residents and community organizations inevitably bump up against large-scale structural constraints—no matter how much access and influence they have with local decision-makers—as they try to change local policy to meet their goals. In recent decades, American governments at all levels from local to national have been affected by the spread of neoliberal ideology, encouraging a turn toward A city’s civic conventions form an important piece of the organizational environment in which community gardening programs develop and define themselves. Yet what is possible for urban agriculture in any given city is also contingent upon its political-economic context. As urban political ecologists would describe it, ideas about appropriate uses for urban space combine with material flows and conditions, as well as ideas governing the legitimacy of governments themselves, in order to determine the actual production of urban socio-nature . In this regard, the distribution and character of urban agriculture in any city is influenced by local economic pressures, the sources and extent of public resources, and political factors at larger scales such as the laws and activities of state and federal governments. These elements of urban political economy can be seen as the municipal government’s own organizational environment, plant grow table which the government and its representatives must attend to in order to maintain their legitimacy, resource flows, and survival.

Whether in pursuit of land tenure for community gardens or other public investments in quality of life, residents and community organizations inevitably bump up against large-scale structural constraints—no matter how much access and influence they have with local decision-makers—as they try to change local policy to meet their goals. A primary set of structural constraints affecting all three cities is their existence in a market economy. In recent decades, American governments at all levels from local to national have been affected by the spread of neoliberal ideology, encouraging a turn toward privatization and new forms of commodification, reduction in taxes and public services, and government intervention to support market processes through deregulation and “entrepreneurial” initiatives . Local governments differ on many fronts, as reflected in the civic conventions they pay homage to, but in the US context they have all been forced into a fiscal squeeze by the reduction of federal funding, and they have confronted this challenge with the shared goal of increasing property values, the local population, and with them the overall prosperity of their local economy . All three case-cities are participants in a globalizing competition to attract capital and “win” at urban growth, and although they vary in their recent histories of “winning” and “losing” the competition for growth, all three cities show how urban growth machine logic and the political-economic pressures on municipalities influence the ways in which urban agriculture has been legitimized as a long-term land use. One common thread is the commodification of nature that runs concurrently with the commodification of land. In each of the case-cities, urban agriculture advocates have taken a different approach to building an economic argument that bolsters the legitimacy of urban agriculture as a land use.

The commonality—bolstering urban agriculture’s legitimacy with an economic rationale—reflects how pervasively market logic is applied to land use in American cities, while the differences between the cases demonstrate variations in how land is commodified based on the local growth coalition’s status in the competition for capital. By drawing attention to the ways that commodification of nature contributes to the production of uneven urban environments, urban political ecology enhances understanding of growth machine dynamics and their impact on the use value available to residents.In a similar vein, urban political ecologists employ the metaphor of urban metabolism to show how the constant reconfiguration of socio-natural space opens up opportunities for transforming relations of power. Addressing the tension between earlier Marxist and more recent actor-network theory approaches within the field of urban political ecology, Heynen highlights the “egalitarian potential that is embedded within a robust conceptualization of urban metabolism” . According to political ecologists, the tendency of nature to reproduce itself freely runs counter to the private property foundations of capitalism, and urban agriculture holds radical potential as an opportunity for people to produce and consume outside of the market, nourishing non-capitalist material flows . However, because the land on which urban agriculture occurs is commodified, I argue that this radical potential is limited in important ways. Urban growers and the spaces they cultivate do contribute to the creative dynamism of socio-natural circulation: they work to reshape the ecology of cities, sustain bodies left undernourished by the capitalist food system, and promote a wider reimagining of urban relations; however, these material and discursive metabolic flows are still subject to the gravity of capitalist property relations and the mutually reinforcing interests of urban growth coalition members.

Asserting the ongoing relevance of Marxist readings of urban political ecology, I show in this chapter how urban political economy serves as an inescapable force influencing land use policy and the decision-making of elected officials. As noted above, in all three cities I investigated, community garden organizations ultimately succeeded in legitimizing urban agriculture as a land use by building narratives that emphasize the potential economic benefits of growing food on vacant lots, a commonality which demonstrates just how strong urban growth and market logics are as governing principles in US cities. Yet there is more to learn from comparing the commodification of nature across the three cases. The economic rationales for urban agriculture developed along distinct trajectories that illustrate how variations in organizational legitimation strategies, local economic conditions, and state-level political contexts combine in the construction of different discursive frames and physical manifestations of urban nature. Comparatively, the local governments in Milwaukee and Philadelphia have faced more acute financial strain in recent decades than the City of Seattle. Milwaukee and Philadelphia have both struggled in the globalized competition for urban growth, while Seattle has largely succeeded. Compounding the effects of reduced federal funding, capital flight has limited the public resources available for social services and urban agriculture investment in both Milwaukee and Philadelphia. Many of the cascading challenges and social maladies are similar for all cities coping with capital flight, but Milwaukee and Philadelphia have diverged in how they construct the role of land in reversing the city’s fortune. In Milwaukee, land is a lifeline that needs to be reserved for potential property tax revenue, while in Philadelphia, land is a liability that has burdened the city budget and deterred development. In Seattle, where the local growth coalition has been winning in the competition to attract capital and the creative class, land has served as a selling point for the city’s livability. The City of Seattle currently has the most public resources available to invest in its community gardens—but upon close inspection, the benefits still accrue unevenly.In Milwaukee, civic conventions that support bottom-up governance facilitated the communication of resident desires regarding urban agriculture, hydroponic table including access to vacant lots and public resources to improve existing projects. As much as city officials are receptive to resident desires and cognizant of the multiple potential ways that urban agriculture works to meet these desires, the scale of poverty in Milwaukee—and legal limitations imposed by state laws—make it difficult for the municipal government to provide consistent financial support for community gardens and similar resident-led initiatives. Facing a severely constrained budget and compounding social problems caused by capital flight and economic decline, the City of Milwaukee is essentially caught doing triage as it attempts to address pressing social problems and attract new investment to regrow its tax base and the economy. Like many cities in the Midwest, Milwaukee has struggled to maintain its economic base with the decline of American manufacturing. In every decade since 1960, the city’s population has decreased, with the most precipitous contraction between 1970 and 1980 when the city lost 11% of its residents. It was during this time that in Milwaukee, as in many other American cities, community gardening received a surge of attention as a strategy to help residents feed themselves amid rising unemployment and higher food costs. Unemployment and poverty persist as major problems in Milwaukee today; the poverty rate is over 25%, and while the unemployment rate has moderately improved to a little under 7% in 2021, the rate for the city’s Black population is almost twice as high . With the decline of the manufacturing sector and inadequate access to transportation, many in Milwaukee—especially on the Near North Side, with the highest concentration of Black residents—cannot commute to what jobs are available .

High unemployment and concentrated poverty have brought on a host of problems including food insecurity, poor health outcomes, crime, and housing instability .Because urban agriculture has been legitimized as a land use and city leaders appreciate potential benefits that the gardens provide, officials have helped gardeners find funding where possible. In addition to the funding from CIP grants described in chapter 3, the Common Council has allocated over $600,000 for beautification and food access initiatives in recent years, some of which has been used to support community gardens. Given the city’s dire fiscal situation, such an amount of money that indicates the impact that urban agriculture organizations have made on the city’s priorities. Without the resources to provide more from the municipal budget, supportive city officials have partnered with other organizations in the region to leverage additional funding for Milwaukee’s community gardens and other green spaces. One source of funding is directly tied to the notion of urban agriculture as a source of employment. In partnership with the county’s federally funded workforce development office, Employ Milwaukee, the City of Milwaukee runs a summer youth employment program called Earn & Learn. Employ Milwaukee pays the wages for young people ages 14-24 who work for local government, nonprofit, and faith-based organizations and gain marketable skills in the process . Groundwork Milwaukee and some individual community gardens participate in Earn & Learn, employing youth to maintain gardens and other green spaces or to prepare and sell food from local urban farms. The organizations could not afford to pay the youth from their own budgets, but they are able to supervise them and provide job training that is considered a valuable workforce development experience by the county, the federal government, and the corporate and philanthropic donors that support Earn & Learn. As governments have reduced their own budgets and the scope of social service provision, the Earn & Learn program is typical of the kind of public-private partnerships that are expanding as the public sector becomes increasingly reliant on nonprofits to fulfill a public service. Furthermore, the fact that “workforce development” is considered a public service at all demonstrates the restructuring of relationships between the public, private and third sectors that has occurred through the influence of neoliberal ideology. With limited resources for the public services of food provision, urban beautification, and community programming, the City of Milwaukee seems to be doing what it can to support these areas as an ancillary benefit of the Earn & Learn workforce training, which is ultimately funded to benefit the private sector. The City of Milwaukee has found another financially motivated partner to support community gardens and other open space investments in the Milwaukee Metropolitan Sewer District . Like 850 other municipalities in the US, Milwaukee uses a combined sewer system which drains storm water along with sewage and industrial wastewater, creating the risk for sewer overflows during heavy rainfall that presents a “priority water pollution concern” for the federal government . Due to climate change, the Great Lakes region is facing an increased likelihood of heavy rainfall events—and therefore more frequent combined sewer overflows . Because of the potential for being fined by the Environmental Protection Agency when overflows occur, local water utilities with combined sewer systems, especially those in the Great Lakes region, have a serious financial interest in increasing their capacity for storm water management. Working in partnership with the City of Milwaukee, the MMSD and the Fund for Lake Michigan have invested billions of dollars to expand both “grey” and “green” infrastructure for storm water management—not only increasing the capacity of pipes and underground storage tanks, but also adding trees and bioswales and preserving open spaces so that more rainwater can be absorbed into the ground rather than flowing into the sewer system.

When civic conventions are built into the local governance infrastructure, such as the mandates of various agencies or the procedures for urban planning, these formalized conventions are an aspect of the local political opportunity structure. That is, civic conventions involve legal and institutional arrangements that can present openings for social movements to pursue particular policies or decisions . Civic conventions in the form of policy infrastructure create important leverage points for organizations to apply political pressure, while conventions in the form of ideas are important to movement formation and mobilization. Civic conventions are not uniform across the three cities I investigated, yet as this chapter will demonstrate, these features of the local context have played a role in shaping the nature of mobilization to support urban agriculture in all three cases. The political opportunity structure in Milwaukee supported efforts to legitimate gardens through insider strategies to craft and enact supportive policy, while the discursive opportunity structure seemed to suggest less need or opening for widespread mobilization. Philadelphia’s civic conventions created essentially the opposite opportunity structure, in which advocates have successfully organized to build pressure from the outside with narratives about the injustice and inefficiency of the city’s existing policies. In Seattle, both the discursive and political opportunity structures supported the gardeners’ efforts to preserve their sites; periods of both insider and outsider strategies have contributed to the robust, secure, seedling grow rack and thoroughly institutionalized network of gardens Seattle has today.The civic conventions in Milwaukee include a tradition of bottom-up governance that has translated from ideas to infrastructure over time.

As a result, urban agriculture organizations have enjoyed a political opportunity structure favorable to voicing their interests directly to city officials, securing policy improvements and some public resources for their projects, without having to depart from their legitimized role as community benefit organizations. However, as Chapter 4 will explain, public resources in Milwaukee are severely constrained, meaning the city government has ultimately been unable to invest much in garden development or preservation, no matter how legitimate they consider urban agriculture to be. Additionally, the local civic conventions foster an expectation of bottom-up engagement while assuming good governance overall; these civic conventions do not broadly extend to an expectation that citizens should engage in ongoing activism and social movement activities to pressure their government for accountability. In other words, the discursive opportunity structure is less favorable to mobilization in defense of threatened gardens. Overall, Milwaukee’s civic conventions have created opportunities for community-based organizations to use insider advocacy strategies through the existing infrastructure for bottom-up governance, without presenting as much opportunity for organizations to organize a robust social movement to pressure city officials for longer-term garden tenure or greater community control over land use. Historically, Milwaukee was the center of “sewer socialism,” a political movement organized around public investments in physical infrastructure. Between 1910 and 1960, the Socialist Party was highly successful in Milwaukee politics, winning public support in large part because of honest-government platforms and improvements that Socialist officials achieved in sanitation, water and energy systems, and community parks—including the preservation of the Milwaukee lakefront for perpetual public access .

Unlike Socialist Party politics elsewhere, Milwaukee’s Socialist movement was less ideological and more pragmatic. The civic conventions that developed in Milwaukee as a legacy of this era include ideas about good governance, but not as much identification with confrontational “usvs.-them” politics as may be expected for a city with a strong Socialist history. Nevertheless, an ethic of straightforward and transparent policy making in the interest of the general public has endured from the days of sewer socialism, contributing to the development of some bottom-up governance infrastructure. One notable element of the city’s governance infrastructure that serves to actualize resident ideas is the Community Improvement Projects program administered by the Neighborhood Improvement Development Corporation. Through this program, the city provides matching grants of up to $4,000 for resident-proposed projects that “stimulate resident engagement and support sustainable projects within a small geographic area” . Community gardens across the city have won these grants to support garden improvements, increasing the legitimacy of these sites because of the city’s endorsement and financial backing as represented by the CIP award. In recent years, particularly through its Department of Community Development, the City of Milwaukee has paid attention to residents’ ideas and priorities and has brought them into consideration in their urban planning. In 2012 and 2013, the Barrett administration conducted a survey and outreach meetings with residents to develop a sustainability plan for the city. One interviewee stressed that the prevalence of food in public opinion was unexpected: “when surveys have been taken over the years around Milwaukee, and there are issues around sustainability, I think the City people were shocked how much food came up” .

The ReFresh MKE Plan produced in 2013 showed that residents identified “empty lots and abandoned buildings” and “access to healthy food” as two of the city’s greatest sustainability challenges . Furthermore, “Fresh local food” was the single most common response given for “ideas that you think Milwaukee should focus on in its Sustainability Plan.” At the same time as ReFresh MKE was being drafted, the Department of Community Development was compiling a Vacant Lot Handbook with ideas for how residents could work with the city to repurpose unused land, based on examples of existing neighborhood projects that residents had initiated—including community gardens. As they developed these plans with attention to resident activities and priorities, city officials gained appreciation for the potential for urban agriculture to address important public needs. Thus, urban agriculture increased its legitimacy in the eyes of city officials as a tool to address public priorities developed from the bottom up. Adhering to civic conventions supporting governance in the public interest, Milwaukee city officials have been receptive to many proposals related to urban agriculture. The Common Council has approved land transfers to some formally organized community gardens located on unbuildable lots or in the city’s most economically depressed neighborhoods. When Will Allen, a local celebrity and nationally renowned director of Growing Power, sought to build a 5-story vertical farm and urban agriculture center, the city’s planners and Common Council worked with him to make necessary changes to the zoning code. The Common Council also approved a $250,000 forgivable loan for the expansion of Sweet Water Organics, an aquaponics business that hoped to scale up its operations and create more urban agriculture jobs. In 2012, in pursuit of a $5 million award in the Bloomberg Mayors Challenge, a competition to support innovative ideas for city improvement, the Barrett administration sketched out a proposal around addressing foreclosed properties while growing the local food system. When they made it to the semi-final round of the challenge, the administration set up a website to receive project ideas from Milwaukee residents, and then held a public forum to hear presentations for the top ten ideas. In all of these situations, greenhouse growing racks the city showed its interest in urban agriculture and openness to advocates’ proposals for new initiatives. Demonstrating the favorable political opportunity structure for garden advocates in Milwaukee, the city government has also been amenable to broader policy changes that facilitate urban agriculture. In 2010 the Common Council and city planners collaborated with the Milwaukee Food Council to revise the city’s zoning policy in a way that would permit urban agriculture in almost all parts of the city. With government officials so receptive to advocates’ input, the leaders of urban agriculture organizations my not have felt it necessary to mobilize the public around preserving community gardens, as doing so would potentially step outside the city’s civic conventions. While ideas about good governance are widely shared, they largely assume that the city officials will act in the public interest without needing constant vigilance and the pressure from grassroots mobilization and protest. Ideas about the value and need for active civic participation are not as widespread in Milwaukee as, for example, I found them to be in my investigation of Seattle. Over the history of the Milwaukee Urban Gardens / MKE Grows program, gardeners have been asked at a few moments to call or write to their Aldermen or to attend a particular public hearing. However, at no point did the program or other advocates in the city appear to sustain any outsider political strategies, as has occurred in both Seattle and Philadelphia.

Out of the three cities, Milwaukee interviews and archival materials demonstrated the least engagement with neighborhood associations or citizen advisory committees. In my qualitative analysis of in-depth interviews and community documents, codes for civic participation, citizen voice, organizing and mobilization, and political pressure or influence were also the least frequent in Milwaukee documents and interviews, while the code for assumed city support had its highest frequency in Milwaukee. As mentioned above, the city sold some land in its inventory to community gardening groups; this happened between 2013 and 2017, with very little public engagement. In the six Common Council meetings where these land sales were approved, the only people who showed up to speak were the purchasers themselves and Yves LaPierre, an official from the Department of Community Development’s real estate division who manages the city’s garden leases. Apparently, LaPierre’s presence alongside the purchasers served to confer adequate legitimacy on the transaction for it to win council approval. Additional supporters of the purchasing organization, community gardeners or other urban agriculture advocates did not participate in any of the hearings. Their absence aligns with the city’s civic conventions that suggest grassroots political pressure is not a normative aspect of the local public’s civic expectations or repertoire. Indeed, the city has acted favorably toward urban agriculture without much public pressure. With Will Allen forming personal relationships with Mayor Barrett and other city officials and bringing a national spotlight to Milwaukee as a place using urban agriculture to improve people’s lives, government support for urban agriculture appears to have been greater than for other types of resident-driven activity. The city’s multi-million-dollar HOME GR/OWN program demonstrates a belief in the potential of urban agriculture as a community investment. This “catalytic project,” designed to meet goals in the ReFresh MKE sustainability plan, leverages public funds, land and staffing along with private investments and philanthropic support specifically to repurpose vacant lots and help people grow food. In Milwaukee, the prestigious national awards that Will Allen has won for his innovations in urban agriculture have helped to bring urban agriculture additional legitimacy along with that accrued due to the city’s baseline receptivity to resident interests. City officials have come to appreciate how urban agriculture could be used to define the city, attract outside funding, and build the local economy. However, this appreciation has its limits. As Chapter 4 will illustrate, city officials are loath to remove potentially developable properties from the tax rolls by transferring ownership to a tax-exempt organization. Eight out of my 18 interviewees, both garden advocates and city officials, stated this as if it were a matter of fact. One garden program leader, recounting a time when they were previously told to move their garden from a city-owned lot, explained that the city was prioritizing a potential development over the garden “because the city of course is looking at their tax base. And being a nonprofit, whether we purchase the land or whether we’re leasing the land, the city’s not making any money that way” . Like other interviewees from Milwaukee, this program leader took for granted that the city’s primary interest in land use decisions is tax revenue. Widely recognizing the limits to the city’s appreciation for urban agriculture, garden advocates in Milwaukee have rarely mobilized to resist garden removal. Both before and after MUG was established, when particular gardens have faced development threats, the more common reaction has been a sense of inevitability. Thus, while government support for urban agriculture is often assumed in Milwaukee, the people involved in urban agriculture projects understand that support only extends so far. In line with the city’s civic conventions, advocates have used the political opportunity structures available to them, such as Community Improvement Projects funding and the Barrett administration’s receptivity to citizens’ ideas about urban agriculture, to advance pragmatic policies to improve residents’ lives through urban agriculture. However, Milwaukee’s discursive opportunity structure does not support more confrontational strategies or radical, redistributive demands.

While Milwaukee had never made urban agriculture illegal, as many other cities had, gardening activities were still technically constrained in the industrially zoned areas with most of the large vacant lots, so the land use policy task force worked to get the zoning laws changed. Under Wiggins’ leadership, MUG was also able to negotiate longer leases for many of the gardens in its network located on city-owned lots. Longer leases didn’t mean preservation, but for gardeners, having assured access to a site for three years rather than one season at a time increased motivation to invest time and labor into the space and its soil. In its early years, MUG struggled to gain legitimacy as a land trust, but in the process of networking with other organizations and engaging with the public, the organization gradually shifted its goals and eventually gained legitimacy by meeting needs more salient to the community. While MUG was trying to gain legitimacy as a land trust, building its local brand through media coverage, events and advertisements, the organization began to receive requests for different kinds of garden support. Gardeners at existing sites wanted help with maintenance, and some people sought MUG’s help finding or starting a garden near them. As raising large enough sums to purchase land was proving difficult, the organization reoriented its activities toward providing technical support and education about gardening to bolster the function of a growing network of self-organized gardens, grow rack influencing land-use policy and planning, and eventually managing leases with the city for gardens on city-owned parcels. In 2013, MUG’s shift from garden preservation to garden support was solidified by their merger with Groundwork Milwaukee, an organization centered on environmental programming activities and job training for at-risk youth.

The two organizations had been sharing office space with other nonprofit groups at the Milwaukee Environmental Consortium, and they collaborated on projects such as installing a cistern and solar pump for sustainable water access at a MUG-owned garden in 2011. Seeing how much their activities were aligned, the organizations’ leaders decided to join MUG with Groundwork Milwaukee in order to save money on overhead. As MUG’s 2012 annual report explained, “The BIG NEWS for the upcoming year is an agency merger with our sister organization, Groundwork Milwaukee. The anticipated merger will allow MUG to be MORE EFFECTIVE and produce efficiencies that will grow more and better gardens throughout Milwaukee’s neighborhoods” . When the two organizations merged in 2013, and MUG became a program of Groundwork Milwaukee, Antoine Carter had been working as the Membership and Outreach Manager for Groundwork Milwaukee. Since 2011, Carter had coordinated youth activities such as running a young farmers’ CSA and building infrastructure for local community gardens. When Carter became the Program Manager for MUG shortly after the merger, he brought with him the experiences of garden-based youth development and community engagement, plus the perspective of someone who had grown up in the disadvantaged Near North Side of Milwaukee—a first for the organization’s leadership. In 2014, at a University of Wisconsin -Milwaukee panel discussion on “Home and Garden: Can Urban Agriculture Save our Neighborhoods?” Carter introduced MUG as “Milwaukee’s best kept secret” and detailed examples of the gardens that Groundwork Milwaukee was helping to install, explaining how these various sites were transforming their neighborhoods—bringing different groups together in one space, healing community trauma, and inspiring young men like him .

Under Carter’s leadership, MUG continued to coordinate garden leases and help residents start new gardens, while placing a greater emphasis on community engagement and programming—especially activities and job training opportunities for Groundwork Milwaukee’s “Green Team” of paid youth work crews. While MUG had struggled to gain legitimacy as a land trust, the organization found a meaningful role providing garden support and event programming; in the effort to maintain this legitimacy over time, MUG amplified a particular narrative around the benefits of urban agriculture in Milwaukee. Once MUG merged with Groundwork Milwaukee, leveraging public funding and grant sources to employ youth in garden maintenance and service-learning activities became a core function of the program. In its grant applications, media statements and newsletters, the program highlighted the benefits of urban agriculture as a tool for youth development and economic opportunity. MUG was also involved in community building activities, but it did not emphasize these in public communications as much as the youth and employment aspects. Ultimately, while community building remained core to MUG’s work, the framing focused on youth and jobs aligned well with that of other prominent nonprofit organizations in the city that engaged in urban growing, which will be discussed more below.Milwaukee Urban Gardens began by emphasizing its role in defending local gardens from the threat of development and thereby improving quality of life for Milwaukee residents, but this narrative never gained traction , so MUG’s focus shifted over time toward community programming, youth education, and employment as the program gained legitimacy for these activities and systematized its operations in order to maintain that legitimacy.

MUG’s mission continued to be about improving quality of life for Milwaukee residents, but the understanding of how to fulfill that mission evolved from securing permanent gardens to enriching the social life of garden spaces. Having been unable to successfully gain legitimacy for the work of preserving gardens, MUG was concomitantly unable to legitimize urban agriculture as a permanent land use, and today, most of Milwaukee’s community gardens are still vulnerable to development. MUG’s efforts have contributed to longer leases for many of the city-owned garden sites, and increased tenure promotes increased time investment by gardeners who maintain the sites. MUG has undoubtedly helped legitimize urban agriculture in Milwaukee by building a narrative around their value for youth and employment training and by providing the administrative infrastructure that affords gardeners and garden sites more continuity, greenhouse grow tables but this legitimacy does not invoke permanence. Furthermore, some of the lots that MUG purchased opportunistically in its early years are not active as gardens anymore, and they actually pose a slight burden to the organization in terms of property taxes and upkeep. Paradoxically, these empty sites may serve as symbols of urban agriculture’s temporary nature despite being acquired with the goal of permanence. Today, Groundwork Milwaukee engages with city officials regularly in managing leases and water permits for various gardens, but the organization does not appear to be actively pushing for longer land tenure for the sites in its network or mobilizing gardeners to achieve more favorable urban agriculture policy. Two factors that help explain why Groundwork Milwaukee doesn’t emphasize gardener organizing are the local civic conventions, which will be discussed more in chapter 3, and the wider organizational context of urban agriculture in Milwaukee. As noted above, MUG was not the first organization to oversee community gardens in Milwaukee; it was also not the most prominent in legitimizing and advocating for urban agriculture in the city. That distinction goes to Growing Power, a nonprofit urban farm with national renown. Growing Power’s founder, Will Allen, along with the leaders of other nonprofits such as Walnut Way, has played a large role in shaping the city’s relationship with urban agriculture. Allen started Growing Power in 1993, and as the organization grew it increasingly focused on addressing problems in its near north-side neighborhood by engaging at-risk youth and offering jobs to hard-to-employ people such as those with a criminal record, all in order to sell fresh produce affordably. Along with his innovative aquaponic growing techniques, this model earned Allen significant awards, including a Ford Leadership for a Changing World award in 2005 and a MacArthur Genius Grant in 2008. As noted above, in addition to Growing Power and MUG, other local organizations have contributed to the legitimacy of and appreciation for urban agriculture as a land use in Milwaukee. The Walnut Way Conservation Corporation, a community development corporation focused on revitalizing the Lindsay Heights neighborhood on Milwaukee’s Near North Side, has also elevated the status of urban agriculture locally. Beginning in the 1990s, founders Sharon and Larry Adams organized the installation of community gardens and orchards at the request of neighborhood residents, who wanted to grow peaches and do something positive with vacant lots. From this network of agricultural spaces, Walnut Way now sells produce, canned goods, and value-added products to Milwaukee residents and restaurants. They employ youth and formerly incarcerated people in landscaping as well as agriculture and food production, providing job training and economic development while transforming the physical appearance of the neighborhood.

As with MUG and Growing Power, Walnut Way has maintained legitimacy in part by its emphasis on job training, which has further solidified the local understanding of urban agriculture as beneficial for its workforce development potential. Another organization often mentioned as a source of legitimacy for urban agriculture in Milwaukee is Victory Gardens Initiative . Since 2009, VGI has organized an annual “garden blitz” during which hundreds of volunteers install up to 500 gardens in backyards across Milwaukee and some of its suburbs. They also manage a 1.5-acre urban farm in the Harambee neighborhood on Milwaukee’s Near North Side. After VGI had leased their farm space for four years through the MUG program, they were able to purchase the parcel from the city—one of only a handful of such cases in which the city sold land for permanent nonprofit-run urban agriculture. In 2013, during the public hearing for the proposed land sale, Alderman Milele Coggs, whose district includes the land in question, called VGI’s farm “great work that’s been done that’s helped the neighborhood and that is a shining example of what can be done with green space in urban areas” . The farm includes an orchard and scale production beds for sale to restaurants and for free distribution to the local community. There is also a community gathering space on the site, along with individual garden plots available for interested community members. VGI uses the site to grow and distribute a significant amount of organic produce, but according to an employee interviewed, their primary mission is actually related to education: they teach neighborhood children, youth in service-learning programs, and other volunteers about organic food production. Yet again, a primary strategy that this organization has used to attract resources and sustain itself over time has to do with youth development, further legitimizing urban agriculture as a vehicle for job training. Walnut Way and VGI are organizations that operate well-known community gardens as a vehicle to fulfill their larger missions, and these organizations have garnered a great deal of media coverage and local recognition for urban agriculture even though it is only one component of their work. The UW Milwaukee County Extension has also operated a network of community gardens since 1978, as noted above; this program, too, has received a lot of positive press coverage, especially in its early years. Over time, the program has tended to operate more on county land outside the city limits, but as a partner to other organizations in the city it has still formed an important part of the local urban agriculture milieu. The situation in Philadelphia is different, in part due to differences in the history of how community gardens have been supported. While gaining legitimacy was a major challenge for Milwaukee Urban Gardens, the same was not true for Philadelphia’s main garden organization. The Pennsylvania Horticultural Society had nearly 150 years of history and a well developed reputation by the time it established the Philadelphia Green program in 1973. The organization’s leader at the time, Ernesta Ballard, is described by many as a visionary; she certainly helped the organization maintain its relevance in changing times when she pushed for the creation of Philadelphia Green. Long known for producing the Philadelphia Flower Show and providing a venue for suburban socialites to show off their horticultural panache, PHS ventured in a different direction with Philadelphia Green by helping urban residents build gardens on vacant lots. In 1978, explaining why PHS was spending $100,000 from its operating budget on the Philadelphia Green program, Ballard explained, “Our people love the program because it gets rid of their guilt about the inner city… It allows them to help people” . This statement reveals a foundational truth about the Philadelphia Green program: the critical audience from which organization leaders sought legitimacy was the PHS donor base rather than the urban gardeners.

The crew bosses are under constant supervision from the crop managers, although they can take short bathroom breaks and they often carry on light-hearted conversations with coworkers. Most crew bosses are US Latinos, with a few mestizo Mexicans and one Mixteco indigenous Oaxacan. They live in the insulated, year-round labor camp. Some of the crew bosses call the Oaxacan workers derogatory names. The crew boss most often accused by pickers of such racist treatment has a daughter, Barbara, who is also a crew boss. Barbara is a bilingual Latina from Texas in her early twenties who has worked the harvest at the farm for 11 years. She attends a community college in Texas every spring and hopes to become a history teacher. She is upset that other crew bosses call Oaxacan people pinche Oaxaco or Indio estupido . She explains to me that Oaxacans are afraid to complain or demand better working conditions because they do not want to lose their jobs. She describes a farm policy stating that if a crew boss fires a picker, they can never be hired by anyone else on the farm. She explains, ‘‘It’s unfair. I think there should be checks and balances.’’ Her family learned English in Texas as well as in the farm-sponsored English classes each night after work. The farm executives intend for these classes to be open to anyone on the farm. Others on the farm believe that the courses are open to all workers except pickers. This unofficial, yet effective exclusion of pickers from the English classes inadvertently shores up segregation on the farm.Pickers are the only group not paid by the hour. Instead, they are considered ‘‘contract workers’’ and are paid a certain amount per pound of fruit harvested. Most live in the camp furthest from farm headquarters and some live in the next furthest camp. Each day, they are told a minimum amount of fruit to pick. If they pick less, they are fired and kicked out of the camp.

The first contract picker I met, a Triqui man named Abelino, explained, ‘‘The hourly jobs, the salaried jobs are better because you can count on how much you will make. But, they don’t give those jobs to us.’’ Approximately 25 people, greenhouse benches mostly mestizo Mexican with a few Mixteco and Triqui people, pick apples. The field boss, Abby, explained to me that picking apples is the hardest job on the farm. Apple pickers work 5 to 10 hours a day, 7 days a week, carrying a heavy bag of apples over their shoulders. They repeatedly climb up and down ladders to reach the apples. This job is sought after because it is known to be the highest paid picking position. However, the majority—350 to 400—of pickers, often called simply ‘‘farm workers,’’ work in the strawberry fields for one month, followed by three months in the blueberry fields. Other than a few Mixtecos, they are almost all Triqui men, women, and children; agricultural workers can legallybe 14 years or older. Most pickers come with other family members. The official contract for strawberry pickers is 14 cents per pound of strawberries. This means that pickers must bring in 50 pounds of de-leafed strawberries every hour because the farm is required to pay Washington State minimum wage . In order to meet this minimum, pickers take few or no breaks from 5 a.m. until the afternoon when that field is completed. Nonetheless, they are often reprimanded and called perros , burros, Oaxacos, or indios estupidos. Many do not eat or drink before work so they do not have to take time to use the bathroom. They work as hard and fast as they can, arms flying in the air as they kneel in the dirt, picking and running with their buckets of berries to the checkers. Although they are referred to as ‘‘contract workers,’’ this is misleading. The pay per unit may be changed by the crop managers without warning or opportunity for negotiation. Strawberry pickers work simultaneously with both hands in order to make the minimum. They pop off the green stem and leaves from each strawberry and avoid the green and the rotten berries. During my fieldwork, I picked once or twice a week and experienced gastritis, headaches, and knee, back, and hip pain for days afterward.

I wrote in a field note after picking, ‘‘It honestly felt like pure torture.’’ Triqui pickers work seven days a week, rain or shine, without a day off until the last strawberry is processed. Occupying the bottom of the ethnic-labor hierarchy, Triqui pickers bear an unequal share of health problems, from idiopathic musculoskeletal pains to slipped vertebral disks, from type 2 diabetes to premature births and developmental malformations . Most Triqui workers on this farm are from one village, San Miguel, located in the mountains of Oaxaca, Mexico. Next, I highlight the economic and physical hardships of the pickers on the farm and on the US-Mexico border, touching on the importance of language, ethnicity, and education in the organization of the farm labor hierarchy. I also indicate the importance of immigration and border policies in determining the structural vulnerability of farm workers. Marcelina is a 28-year-old Triqui mother of two. A local non-profit organized a seminar on farm labor for which I invited Marcelina to speak about her experiences migrating and picking. Shyly, she approached the translator, holding her one year-old daughter, speaking in Spanish, her second language.My first day picking, the only people who picked as slowly as I did were two Latina US citizen girls from California and one Latino US citizen manwho commuted from Seattle. After the first week, the two Latina girls began picking into the same bucket in order to make the minimum and keep one paycheck. The second week, I no longer saw the man from Seattle. I asked a supervisor where he had gone, assuming he had decided the work was too difficult and given up. She told me the farm made a deal with him that if he could make it through a week picking, they would give him a job paid hourly in the processing plant. He has been ‘‘one of the hardest workers’’ in the plant since then. I inquired as to why indigenous Mexicans could not get processing plant jobs. The supervisor replied, ‘‘People who live in migrant camps cannot have those jobs, they can only pick.’’ She considered it farm policy without any need for explanation. Thus, marginalization begets marginalization. Structural vulnerability increases along the labor hierarchy and is reinforced by official and unofficial policies, practices, and prejudices .

The indigenous Mexicans live in the migrant camps because they do not have the resources to rent apartments in town. Because they live in the camps, they are given only the worst jobs on the farm. Unofficial farm policies subtly reinforce labor and ethnic hierarchies. These profiles show that the position of the Triqui workers at the bottom of the hierarchy is multiply determined by poverty, education level, language, citizenship status, and ethnicity. In addition, these factors produce each other. For example, a family’s poverty cuts short an individual’s education, which limits one’s ability to learn Spanish , which limits one’s ability to leave the bottom rung of labor and housing. Poverty, at the same time, is determined in large part by the institutional racism at work against Triqui people in the first place. Segregation on the farm is the result of a complex system of feedback and feedforward loops organized around these multiple nodes. Late in my second summer on the farm, the pickers walked out of the field just after the pay per weight was lowered. The pickers listed over 20 grievances about the working conditions, growers equipment from low pay to racist statements from supervisors, lack of lunch breaks to unfair promotions of mestizo and Latino workers over indigenous pickers. Over the next week, several executives and a dozen pickers held meetings to discuss the grievances. The executives were visibly surprised and upset at the explicit racist treatment and differential promotions on the farm. They promptly instructed the crop managers to pass along the message to treat all workers respectfully. Lunch breaks and higher pay were instituted, but were silently rescinded the following summer. The pickers called the document a ‘‘contract’’ and requested signatures from the executives. The farm president filed it as a ‘‘memo.’’ This strike, the temporary nature of its results, and the conversion of the contract into a memo highlight the differential demands and pressures at all levels of the farm hierarchy. The executives demand that all workers aretreated with respect at the same time that their real anxieties over farm survival prohibit them from effectively addressing the primary, economic concerns of the pickers. Although everyone on the farm works for and is paid by the same business, they do not share vulnerability evenly. The pay and working conditions of the pickers function as variables semicontrollable by the farm executives as partial buffers between market changes and the viability of the rest of the farm.Responsibilities, stressors, and privileges differ from the top to the bottom of this hierarchy.

Everyone on the farm is structurally vulnerable, although the characteristics and depth of vulnerability change depending on one’s position within the labor structure. Control decreases and anxieties accumulate as one moves down the pecking order. Those at the top worry about market competition and the weather. The middleResponsibilities, stressors, and privileges differ from the top to the bottom of this hierarchy. The workers on every level of the ladder worry about factors over which they lack control. Everyone on the farm is structurally vulnerable, although the characteristics and depth of vulnerability change depending on one’s position within the labor structure. Control decreases and anxieties accumulate as one moves down the pecking order. Those at the top worry about market competition and the weather. The middlemanagers worry about these factors as well as about how they are treated by their bosses. The pickers also worry about picking the minimum weight in order to avoid losing their job and their housing. The higher one is positioned in the structure, the more control over time one has . The executives and managers can take breaks as their workload and discretion dictate. The administrative assistants and checkers can take short breaks, given their supervisor’s consent or absence. The field workers can take infrequent breaks if they are willing to sacrifice pay, and even then they may be reprimanded. The higher one is located in the hierarchy, the more one is paid. The executives and managers are financially secure with comfortable homes. The administrative staff and checkers are paid minimum wage and live as members of the rural working class in relatively comfortable housing. The pickers are paid piecemeal and live in labor camp shacks. They are constantly aware of the risk of losing even this poor housing. Among pickers, those in strawberries make less money and are more likely tomiss the minimum and be fired than those in apples. This segregation is not conscious or willed on the part of the executives or managers. Rather, inequalities and the anxieties they produce are driven by larger structural forces. While farm executives are vulnerable to macro-social structures, vulnerability is further conjugated through ethnicity and citizenship, changing character from the top to the bottom of the labor hierarchy . Bodies are organized according to the social categories of ethnicity and citizenship into superimposed hierarchies of labor possibilities and housing conditions. The overdetermination of the adverse lot of indigenous Mexican migrant berry pickers tracks along the health disparities seen throughout the public health literature on migrant workers . The focus on risk and risk behaviors in public health and medicine carries with it a subtle assumption that the genesis of vulnerability and suffering is the individual and his or her choices . This focus often leads to blaming inadvertently the individual victim or their ‘‘culture’’ for their structurally produced suffering . Public health and medical interventions are planned with the goal of changing individual choices, behaviors, and values. The concept of structural vulnerability, on the other hand, refocuses our analysis onto the social structure as the locus of danger, damage, and suffering. Without such a concept, diagnoses and interventions rarely correspond with the context of suffering and may instead comply with the very structures of inequality producing the suffering in the first place .

Among these farmers that responded with a list of key nutrients, some talked about having their nutrients “lined up” as part of their fertility program. This approach involved keeping nutrients “in balance,” such as for example, monitoring pH to ensure magnesium levels did not impact calcium availability to plants. These farmers also emphasized that though nitrogen represented a key nutrient and was important to consider in their farm operation, tracking soil nitrogen levels was less important than other aspects of soil management, such as promoting soil biological processes, maintaining adequate soil moisture and aeration, or planting cover crops regularly. As one farmer put it, “if you add nutrients to the soil, and the biology is not right, the plants will not be able to absorb it.” Or, as another farmer emphasized, “It’s not about adding more [nitrogen]… I try to cover crop more too.” A third farmer emphasized, that “I don’t use any fertilizers because I honestly don’t believe in adding retroactively to fix a plant from the top down.” This same farmer relied on planting a cover crop once per year in each field, and discing that cover crop into the ground to ensure his crops were provided with adequate nitrogen for the following two seasons. While most farmers readily listed key nutrients, several farmers shifted conversation away from focusing on nutrients. These farmers generally found that this interview question missed the mark with regards to soil fertility. One farmer responded, “I’m not really a nutrient guy.” This same farmer added that he considered [soil fertility] a soil biology issue as much as a chemistry issue.” The general sentiment among these farmers emphasized that soil fertility was not about measuring and “lining up” nutrients, grow lights for cannabis but about taking a more holistic approach.

This approach focused on facilitating conditions in the soil and on-farm that promoted a soil-plant-microbe environment ideal for crop health and vigor. For example, the same farmer quoted above mentioned the importance of establishing and maintaining crop root systems, emphasizing that “if the root systems of a crop are not well established, that’s not something I can overcome just by dumping more nitrogen on the plants.” Another farmer similarly emphasized that they simply created the conditions for plants to “thrive,” and “have pretty much just stepped back and let our system do what it does; specifically, we feed our chickens whey-soaked wheat berries and then we rotate our chickens on the field prior to planting. And we cover crop.” A third farmer also maintained that their base fertility program—a combination of planting a cover crop two seasons per year, an ICLS chicken rotation program, minimal liquid N-based fertilizer addition, and occasionally compost application—all worked together to “synergize with biology in the soil.” This synergy in the soil created by management practices—rather than focusing on nutrient levels—guided this farmer’s approach to building and assessing soil fertility on-farm. Another farmer called this approach “place-based” farming. This particular farmer elaborated on this concept, saying “I think the best style of farming is one where you come up with a routine [meaning like a fertility program] that uses resources you have: cover crops, waste materials beneficial to crops, animals” in order to build organic matter, which “seems to buffer some of the problems” that this farmer encountered on their farm.

Similar to other farmers, this farmer asserted that adding more nitrogen-based fertilizer did not lead to better soil fertility or increase yields, in their direct experience. Regardless of whether farmers listed key nutrients, a majority of farmers voiced that nitrogen was not a big concern for them on their farm. This sentiment was shared among most farmers in part because they felt the amount of nitrogen additions from fertilizers they added were insignificant compared to nitrogen additions by conventional farms. Farmers also emphasized that the amount of nitrogen they were adding was not enough to cause environmental harm; relatedly, a few farmers noted the absurdity and added economic burden of the recent nitrogen management plan requirements—specifically among organic farms with very low N-based fertilizer application. The majority of farmers also expressed that their use of cover crops and the small amount of N-based fertilizer additions as part of their soil fertility program ensured on-farm nitrogen demands were met for their crops. Across all farmers interviewed, cover cropping served as the baseline and heart of each fertility program, and was considered more effective than additional N-based fertilizers at maintaining and building soil fertility. Farmers used a range of cover crop species and often applied a mix of cover crops, including vetches and other legumes like red clover and cowpea , grains and cereals like oats . Farmers cited several reasons for the effectiveness of cover cropping, such as increased organic matter content, more established root systems, greater microbial activity, better aeration and crumble in their soils, greater number of earthworms and arthropods, improved drainage in their soils, and more bioavailable N.

Whereas farmers agreed that “more is not better” with regards to N-based fertilizers, farmers did agree that allocating more fields for planting cover crops over the course of the year was beneficial in terms of soil fertility. However, as one farmer pointed out, while cover crops provide the best basis for an effective soil fertility program, this approach is not always economically viable or physically possible. Several farmers expressed concern because they often must allocate more fields to cover crops than cash crops in any given season, which means that their farm operation requires more land to be able to produce the same amount of vegetables than if they had all their fields in cash crops. Farmers also shared that in some circumstances, such as in early spring, they are not able to realize the full potential of a winter cover crop if they are forced to mow the cover crop early to plant cash crops and ensure the harvest timeline of a high-value summer vegetable crop. The cover crop approach to soil fertility takes “persistence,” as one farmer emphasized; another farmer similarly pointed out that the benefits of cover cropping “are not always realized in the crop year. You’re in it [organic agriculture] for the long haul, there is no quick fix.” Indeed, farmers who choose to regularly plant cover crops to build soil fertility, rather than just add N-based fertilizers, reported that they came up against issues of land tenure and access to land, market pressures, and long-term economic sustainability. To build on conversations about soil fertility, farmers also provided responses to interview questions that asked them to elaborate on the usefulness of available soil tests to gauge soil fertility more broadly—and then more specifically, the usefulness of soil tests in informing their soil fertility program and/or management approaches on-farm. Overall, only three of 13 farmers reported regularly using and relying on soil tests to inform their soil fertility program or aspects of their farm operation. These farmers offered very short responses and did not elaborate. For example, one farmer shared that they “test twice a year in general,” and that they “rely on the results of the soil tests to tweak [their] fertility program.” Another farmer said briefly, “We use soil tests… we utilize them to decide what to do to try to improve the soil.” A third farmer admitted that though he “used to do a soil test every year, literally used to spend hundreds of dollars per year on soil tests,” he found that the results of soil tests did not change year-to-year and were, as he put it, very “stable.” This particular farmer no longer regularly uses or relies on soil testing for their farm operation. The remaining ten farmers confirmed that they had previously submitted a soil test, usually once and most often to a local commercial lab in the region. These farmers expressed a range of sentiments when asked about the usefulness of soil tests, including disappointment, distrust, or both, particularly in the capacity of soil tests to inform soil fertility on their farm. Some farmers said directly, “I just don’t trust soil tests,” or “frankly, I don’t believe a lot in soil testing because it’s too standardized,” indoor cannabis grow system while other farmers initially stated they had used “limited” or “infrequent” soil tests, and then later admitted that they did not use or rely on soil tests on their farm operation. These farmers tended to focus on the limitations of soil tests that they encountered for their particular farm application. Limitations of soil tests discussed by farmers varied. Farmers stated that soil tests often confirmed what they already knew about their soil and did not add new information. For this reason, some farmers used results from a soil test as a guide, while other farmers found results to be redundant and therefore less useful to their farm operation.

Because issues with soil fertility were sometimes linked to inherent soil characteristics within a particular field, such as poor drainage or heavily sandy soil, farmers found that soil tests were not able to provide new insight to overcome these environmental limitations. “I’m not able to correct that environmental limitation [ie, poor drainage] by adding more nitrogen,” one farmer emphasized. A different farmer echoed this sentiment, saying that “I’m not going to magically get rid of issues that soil tests show… I can only slightly move the needle, no matter what I do.” Most farmers recognized that soil tests produced inconsistent results because of differences in timing and location of sampling. As one farmer noted, “You can take the same sample a couple months apart from the same field and get very different results.” Likewise, another farmer shared that, “I still struggle with the fact that I can send in two different soil tests and get two very different results. To me that seems like the science is not there.” Farmers also emphasized that each of their “fields are all so different” with “a lot of irregularity in [their] soil.” According to several farmers, soil tests did not account for variations in soil texture and soil structure, despite their observations of the influence of both edaphic characteristics on soil test results. For example, one farmer pointed out that fields that were plowed or were previously furrow irrigated created marked differences in soil test results. Similarly, another farmer shared that if a sample for soil testing was taken from an irregular patch in a field with heavier clay, differences in soil texture across samples skewed soil test results. If a systematic sampling approach was not considered, several farmers emphasized that results of soil tests might be “misleading.” Another source of inconsistency that farmers voiced stemmed from variation in protocols used across different labs that processed soil samples. One farmer stated that in their experience, “soil tests are not really accurate, because if I use a different lab, a different person [ie, consultant] doing the soil test, it’s all different.” For example, one farmer pointed out that they do not use soluble forms of nitrogen, and instead relied on their animal rotations and cover crops to supply nutrients as part of their fertility program; this farmer emphasized that, “I think we need to get to a place with soil testing where it would be more applicable or be more accurately useful for a farm like mine. For example, with soil testing, if the standards you’re setting, and the markers you’re setting are based on farms that are putting fertilizer on the soil, I don’t think my numbers are going match up. PCA indicated strong relationships among several key management variables; the results of the PCA also provided strong differentiation among farms along the first two principal components, which together accounted for 77.4% of the variability across farms . The first principal component explained 55.1% of the variation, and the second component explained 22.3% of the variation observed across all farms. Both components had eigenvalues greater than 1.0. Additional N-based fertilizer represented the management variable most associated with PC 1—followed by tillage, and inversely ICLS. While crop diversity, cover crop frequency, and crop rotation patterns also contributed to the overall variation explained by PC 1, these management variables were weaker in comparison to N-based fertilizer additions, ICLS, and tillage. On the other hand, variables with the strongest contribution to PC 2 were crop diversity, cover crop frequency, and crop rotation patterns.