Pesticide risk perception and biomarkers of exposure in Florida female farmworkers

Examination of urinary pesticide concentrations, protective behaviors, and risk perceptions among Latino and Latina farmworkers in Southwestern Idaho

INTRODUCTION

Studies have documented high levels of pesticide exposure among men farmworkers; however, few have examined exposures or the experiences of women farmworkers. Data gaps also exist regarding farmworkers' perceived risk and control related to pesticides, information that is critical to develop protective interventions.

OBJECTIVE

We aimed to compare urinary pesticide biomarker concentrations between Latino and Latina farmworkers and examine associations with occupational characteristics, risk perceptions, perceived control, and protective behaviors.

METHODS

We enrolled a convenience sample of 62 farmworkers (30 men and 32 women) during the pesticide spray season from April-July 2022 in southwestern Idaho. Participants were asked to complete two visits within a seven-day period; at each visit, we collected a urine sample and administered a questionnaire assessing demographic and occupational information. Urine samples were composited and analyzed for 17 biomarkers of herbicides and of organophosphate (OP) and pyrethroid insecticides.

RESULTS

Ten pesticide biomarkers (TCPy, MDA, PNP, 3-PBA, 4-F-3-PBA, cis- and trans-DCCA, 2,4-D, Glyphosate, AMPA) were detected in >80% of samples. Men and women had similar urinary biomarker concentrations (p = 0.19-0.94); however, women worked significantly fewer hours than men (p = 0.01), wore similar or greater levels of Personal Protective Equipment (PPE), and were slightly more likely to report having experienced an Acute Pesticide Poisoning (26% of women vs. 14% of men; p = 0.25). We observed inconsistencies in risk perceptions, perceived control, and protective behaviors among men.

DISCUSSION

Our study is one the first to examine pesticide exposure and risk perceptions among a cohort of farmworkers balanced on gender. Taken with previous findings, our results suggest that factors such as job tasks, biological susceptibility, or access to trainings and protective equipment might uniquely impact women farmworkers' exposure and/or vulnerability to pesticides. Women represent an increasing proportion of the agricultural workforce, and larger studies are needed to disentangle these findings.

The effects of inhaled pollutants on reproduction in marginalized communities: a contemporary review

Important differences in health that are closely linked with social disadvantage exist within and between countries. According to the World Health Organization, life expectancy and good health continue to increase in many parts of the world, but fail to improve in other parts of the world, indicating that differences in life expectancy and health arise due to the circumstances in which people grow, live, work, and age, and the systems put in place to deal with illness. Marginalized communities experience higher rates of certain diseases and more deaths compared to the general population, indicating a profound disparity in health status. Although several factors place marginalized communities at high risk for poor health outcomes, one important factor is exposure to air pollutants. Marginalized communities and minorities are exposed to higher levels of air pollutants than the majority population. Interestingly, a link exists between air pollutant exposure and adverse reproductive outcomes, suggesting that marginalized communities may have increased reproductive disorders due to increased exposure to air pollutants compared to the general population. This review summarizes different studies showing that marginalized communities have higher exposure to air pollutants, the types of air pollutants present in our environment, and the associations between air pollution and adverse reproductive outcomes, focusing on marginalized communities.

Respiratory and allergic health effects in children living near agriculture: A review

BACKGROUND

Exposure to pesticides and agricultural burning are likely to co-occur in agricultural communities, but these exposures have remained distinct bodies of research. We reviewed epidemiological studies to identify the respiratory health effects of children exposed to pesticides and agricultural burning through a systematic evaluation of peer-reviewed publications of children living in industrial agricultural areas.

METHODS

Two academic search databases (PubMed and Scopus) were queried for all available studies published in English before May 31st, 2021. The initial search combining both exposure metrics (pesticides and agricultural burning) yielded zero publications and thus the queries were performed and presented separately.

RESULTS

Studies were categorized based on main exposure of interest (i.e., pesticides or agricultural burning) and by respiratory health outcome assessment (i.e., self-reported asthma, acute respiratory symptoms, and lung function measurements). In total we identified 25 studies that focused on pesticide exposures and children's respiratory health, and 12 studies that focused on exposure to agricultural burning and children's respiratory health. A majority of the pesticide studies (18/25) reported a positive association between exposure to pesticides and adverse childhood respiratory health effects. Similarly, most (11/12) of the agricultural burning studies also reported a positive association between exposure to agricultural burning and adverse respiratory health effects.

CONCLUSION

The most frequently studied health outcomes in these publications were acute respiratory symptoms (n = 11 pesticides, n = 3 agricultural burning), followed by asthma (n = 9 pesticides, n = 3 agricultural burning), and lung function measurements (n = 5 pesticides, n = 6 agricultural burning). Although health outcome assessment differed between pesticide studies and agricultural burning studies, similar adverse respiratory health effects were observed across the majority of studies.

Pesticides and environmental injustice in the USA: root causes, current regulatory reinforcement and a path forward

Many environmental pollutants are known to have disproportionate effects on Black, Indigenous and People of Color (BIPOC) as well as communities of low-income and wealth. The reasons for these disproportionate effects are complex and involve hundreds of years of systematic oppression kept in place through structural racism and classism in the USA. Here we analyze the available literature and existing datasets to determine the extent to which disparities in exposure and harm exist for one of the most widespread pollutants in the world – pesticides. Our objective was to identify and discuss not only the historical injustices that have led to these disparities, but also the current laws, policies and regulatory practices that perpetuate them to this day with the ultimate goal of proposing achievable solutions. Disparities in exposures and harms from pesticides are widespread, impacting BIPOC and low-income communities in both rural and urban settings and occurring throughout the entire lifecycle of the pesticide from production to end-use. These disparities are being perpetuated by current laws and regulations through 1) a pesticide safety double standard, 2) inadequate worker protections, and 3) export of dangerous pesticides to developing countries. Racial, ethnic and income disparities are also maintained through policies and regulatory practices that 4) fail to implement environmental justice Executive Orders, 5) fail to account for unintended pesticide use or provide adequate training and support, 6) fail to effectively monitor and follow-up with vulnerable communities post-approval, and 7) fail to implement essential protections for children. Here we’ve identified federal laws, regulations, policies, and practices that allow for disparities in pesticide exposure and harm to remain entrenched in everyday life for environmental justice communities. This is not simply a pesticides issue, but a broader public health and civil rights issue. The true fix is to shift the USA to a more just system based on the Precautionary Principle to prevent harmful pollution exposure to everyone, regardless of skin tone or income. However, there are actions that can be taken within our existing framework in the short term to make our unjust regulatory system work better for everyone.

The Abysmal Organization of Work and Work Safety Culture Experienced by North Carolina Latinx Women in Farmworker Families

The occupational health of immigrant workers in the United States is a major concern. This analysis describes two domains, organization of work and work safety culture, important to the occupational health of Latinx women in farmworker families. Sixty-seven Latinx women in North Carolina farmworker families completed a baseline and five follow-up questionnaires in 2019 through 2021. Fifty-nine of the women were employed in the year prior to the Follow-Up 5 Questionnaire. These women experienced an abysmal organization of work and work safety culture. They experienced significant job churn, with most changing employment several times during the 18-month period. Most of their jobs were seasonal, paid less than $10.00 per hour, piece-rate, and almost all without benefits. The women's jobs had little skill variety (mean 1.5) or decision latitude (mean 1.1), but had high psychological demands (mean 2.0). Work safety climate was very low (mean 13.7), with 76.3% of women noting that their supervisors were "only interested in doing the job fast and cheaply" rather than safely. Women employed as farmworkers versus those in other jobs had few differences. Further research and intervention are needed on the organization of work and work safety culture of Latinx women manual workers.

Systematic review of human biomonitoring studies of ethylenethiourea, a urinary biomarker for exposure to dithiocarbamate fungicides

Toxicological and epidemiological studies implicate exposure to dithiocarbamate (DTC) fungicides in adverse health outcomes. However, there is limited information about human exposure to these chemicals. This systematic review determined to which extent human populations worldwide, including children, pregnant women, and adults, are exposed environmentally or occupationally to DTC pesticides and how these exposures compare to the NHANES 2003-2008 population, using urinary ETU data as an outcome measure. PubMed, Embase, and SciFinder were searched using the keywords "ethylenethiourea" or CAS No.: 96-45-7, and urine or urinary. Duplicates and irrelevant studies were removed from the search results based on predetermined exclusion criteria. This screening process identified 17 relevant papers. One additional paper was found independent of this search. Data from studies were extracted using a pre-established data collection form. Ten, two, and five manuscripts reported urinary levels in environmentally exposed adults, children, and pregnant women, respectively. Median ETU levels ranged from 0.15 to 4.7 μg/g creatinine in adults (1994-2017), 0.24-0.83 μg/g creatinine in children (2011), and 2.6-5.24 ng/ml in pregnant women (2011). Eight studies reported urinary ETU levels in mostly agriculturally exposed populations, with median ETU levels ranging from 0.42 to 49.6 μg/g creatinine (1999-2011). With one exception, all studies were conducted between 1994 and 2011. ETU levels in the NHANES 2003-2008 population appeared to be generally lower than most studies identified in this review. This finding suggests that, historically, DTC fungicide exposures in the general population of high-income countries, such as the US, were low, whereas agricultural populations may have experienced higher exposure. Unfortunately, more recent exposure data are missing, especially in countries where DTC pesticides are not being phased out.

Pesticide exposure among Latinx child farmworkers in North Carolina

BACKGROUND

Although pesticides have adverse effects on child health and development, little research has examined pesticide exposure among child farmworkers. This analysis addresses two specific aims: (1) describes pesticide exposure among Latinx child farmworkers in North Carolina, and (2) delineates factors associated with this pesticide exposure.

METHODS

In 2018 (n = 173) and 2019 (n = 156) Latinx child farmworkers completed interviews and wore silicone wristbands for a single day to measure pesticide exposure. Wristbands were analyzed for 70 pesticides.

RESULTS

Most Latinx child farmworkers were exposed to multiple pesticides; the most frequent were pyrethroids (69.9% in 2018, 67.9% in 2019), organochlorines (51.4% in 2018, 55.1% in 2019), and organophosphates (51.4% in 2018, 34.0% in 2019). Children were exposed to a mean of 2.15 pesticide classes in 2018 and 1.91 in 2019, and to a mean of 4.06 pesticides in 2018 and 3.34 in 2019. Younger children (≤15 years) had more detections than older children; children not currently engaged in farm work had more detections than children currently engaged in farm work. Migrant child farmworkers had more detections than nonmigrants. For specific pesticides with at least 20 detections, detections and concentrations were generally greater among children not currently engaged in farm work than children currently engaged.

CONCLUSIONS

Children who live in farmworker communities are exposed to a plethora of pesticides. Although further research is needed to document the extent of pesticide exposure and its health consequences, sufficient information is available to inform the policy needed to eliminate this pesticide exposure in agricultural communities.

Understanding Challenges to Well-Being among Latina FarmWorkers in Rural Idaho Using in an Interdisciplinary, Mixed-Methods Approach

The aim of this study was to identify social, cultural and workplace-related risk factors affecting well-being among Latina farmworkers in rural Idaho. We recruited 70 Latina farmworkers from southwestern Idaho in 2019. We employed an inter-disciplinary, mixed-methods approach—including surveys, focus groups, interviews, and pesticide biomonitoring—to characterize multiple domains that influence well-being, including food security and access, housing conditions, social supports, access to medical care, and workplace safety. Six major themes emerged as primary challenges to Latina farmworkers’ well-being. In the public sphere, study participants identified these challenges as long working hours, concerns regarding pesticide exposure, and lack of enforcement of regulatory protections. Participants’ concerns regarding pesticide exposure were underscored by biological sampling results; multiple biomarkers of pesticide exposure were detected in all samples, with the highest concentrations measured in samples collected from women who reported mixing, loading or applying pesticides. Within the private sphere, food security and provisioning, childcare responsibilities, and social isolation were identified as significant challenges to well-being. Gender, ethnicity, and geography emerged as important, intersecting statuses that shaped the life experiences of these agricultural workers. Our findings suggest that gender may play a particularly critical role in the unique challenges facing Latina farmworkers. As a result, the services and regulations needed to support well-being in this population may be highly specific, and almost certainly include attention to work–family dynamics, pesticide exposure, and social connections.

Pesticide risk perceptions among bystanders of aerial spraying on bananas in Costa Rica

Little is known about how bystanders perceive risks from pesticide use in areas with frequent aerial spraying of pesticides. This research aims to better understand how bystanders (school workers) from three counties of the Limón province in Costa Rica, who did not have a contractual relationship with agricultural production, perceive risks of pesticides in the areas where they work and live. A face-to-face survey was carried out among 475 school workers, of whom 455 completed all 33 questions on pesticide risk perception. An exploratory factor analysis characterized underlying perceptions of pesticide exposure. Nine factors explained 40% of total variance and concerned severity and magnitude of perceived risk, manageability, benefits and support of pesticide use, amongst others. We subsequently analyzed what variables explained the five factors with satisfactory internal consistency, using separate multivariable linear regression models. Older school workers, (male) elementary teachers, and women school workers (particularly from schools situated near agricultural fields with aerial spraying of pesticides), felt greater severity and/or magnitude of risk from pesticide use. This study shows that bystanders are concerned about health risks from pesticide use. Their risk perceptions are not only shaped by gender and age like previously reported in the literature, but also by job title and geographical context. Understanding of what hazards people care about and how they deal with them is essential for successful risk management, bystanders should therefore be considered as a relevant actor in debates around pesticide issues and for informing the development of regulations and risk reduction strategies.

Biomarkers of occupational exposure to pesticides: Systematic review of insecticides

INTRODUCTION

Pesticides are widely used around the world, and rural workers have greater risk of poisoning. The use of biomarkers for insecticides can contribute to the diagnosis and prevention of poisoning.

OBJECTIVE

To identify, in the scientific literature, the biomarkers of occupational exposure to insecticides of different insecticide classes.

METHODS

The PubMed, Lilacs and Embase databases were analyzed using a systematic search strategy and in accordance with the criteria established by the PRISMA methodology. Articles with information related to the use of biomarkers to identify active ingredients, or insecticide metabolites, or effects on the human biological matrices were analyzed.

RESULTS

A total of 840 studies was found, and 30 met the selection criteria. The search identified 118 results for insecticide biomarkers, of which 45% were of exposure, 42% of effect, and 14% of susceptibility. Additionally, 78 were possible biomarkers, and only 67 confirmed to be different biomarkers for insecticides. Acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 3,5,6-trichloro-2-pyridinol (TCP-y), specific for Chlorpyrifos, were among the most common biomarkers identified; however, most metabolites found were non-specific.

CONCLUSION

Various insecticide biomarkers were mentioned; nonetheless, only a few are specific and used to identify the wide range of insecticides to which farm workers are exposed.

Subjective production of exposure to agrochemicals. A scoping review

The intensification of agriculture in countries of the Southern Cone of Latin America has led to a significant rise in the use of agrochemicals. Scientific output in the field of health has concentrated on the epidemiological aspects of this issue and studies addressing the social dimensions of exposure to these substances remain scarce. The aim of this scoping review was to assess the scientific literature on the subjective production of groups exposed to agrochemicals. To this end, searches were conducted of the Scopus, PubMed, BVS, SciELO, and DOAJ databases for articles published between 1991 and 2016. A complementary search strategy drawing on references to other studies in the selected articles was also adopted. The findings show that the studies give subjective production different names and that the predominant themes covered by the literature were risk perception and health beliefs. With regard to understanding-explaining the subjective production process, a series of articles focused on individual lifestyles, while another group considered collective ways of life. The wide-ranging findings suggest that this area is a field of study in dispute, where positivist and functionalist approaches converge with historically situated studies that adopt a critical perspective.

Manganese exposure and working memory-related brain activity in smallholder farmworkers in Costa Rica: Results from a pilot study

Main sources of manganese (Mn) in the general population are diet and drinking water. Mn is also found in ethylene bisdithiocarbamate (EBDC) fungicides used in agriculture or emitted into the air by ferromanganese plants and welding fumes, which can be additional environmental and occupational sources of exposure. High occupational Mn exposure has been linked with motor, behavioral, and cognitive impairment, but its effects on neural function remain poorly understood. We conducted a functional neuroimaging study in a sample of 48 farmworkers in Zarcero County, Costa Rica, an agricultural region where EBDC fungicides are sprayed. We measured Mn concentrations in farmworkers' toenails (n = 40 farmworkers) and hair (n = 33 farmworkers), and recorded brain activity in the dorsolateral prefrontal cortex during a letter-retrieval working memory task using functional near-infrared spectroscopy (fNIRS). We estimated exposure-outcome associations using multivariable linear regression models adjusted for age and education level. Geometric mean (geometric standard deviation) toenail and hair Mn concentrations were 0.40 μg/g (3.52) and 0.24 μg/g (3.54), respectively. We did not find strong evidence that Mn concentrations were associated with working memory-related brain activity in this sample of farmworkers; we also found null associations between working memory task accuracy and brain activity. However, our small sample size may have limited our ability to detect small effect sizes with statistical precision. Our study demonstrates that fNIRS can be a useful and feasible tool in environmental epidemiology for examining the effects of toxicants, like Mn, on neural function. This may prove to be important for elucidating neuropathological pathways that underlie previously reported associations of elevated Mn exposure with neurotoxic effects.

Olfactory Function in Latino Farmworkers Over 2 Years: Longitudinal Exploration of Subclinical Neurological Effects of Pesticide Exposure

OBJECTIVE

We compared patterns of olfactory function over 2 years in pesticide-exposed male Latino farmworkers and male Latino workers in industries without pesticide exposure.

METHODS

At five points over 2 years, workers completed tests of odor threshold (16 concentrations of n-butanol) using a well-established methodology. Tests at two or more time points were completed by 156 farmworkers and 118 non-farmworkers.

RESULTS

Farmworkers required significantly higher odorant concentrations at Contact 1 and across the 2-year follow-up to detect the odor. When adjusted for Contact 1, between-group differences persisted, but odor threshold performance did not worsen over time.

CONCLUSIONS

Pesticide exposure has been linked to neurodegenerative disease, as has declining olfactory function. Persistently poorer olfactory function among pesticide-exposed workers suggests the need to monitor neurological function in this vulnerable worker population.

Farmworker and nonfarmworker Latino immigrant men in North Carolina have high levels of specific pesticide urinary metabolites

This article compares detections and concentrations of specific organophosphate (OP), bis-dithiocarbamate, and pyrethroid pesticide urinary metabolites among Latino male farmworkers and nonfarmworkers in North Carolina. Data are from interviews and urine samples collected in 2012 and 2013. Farmworkers and nonfarmworkers frequently had detections for OP and pyrethroid pesticide urinary metabolites. Detection of bis-dithiocarbamate urinary metabolites was less frequent, but substantial among the nonfarmworkers. The concentrations of organophosphate, bis-dithiocarbamate, and pyrethroid pesticide urinary metabolites were high for farmworkers and nonfarmworkers compared to National Health and Nutrition Examination Survey results. Pesticide urinary metabolite detection was not associated with occupation in nonfarmworkers. Research for reducing pesticide exposure among farmworkers remains important; research is also needed to determine pesticide exposure pathways among Latino nonfarmworkers.

Organophosphate Pesticide Urinary Metabolites Among Latino Immigrants: North Carolina Farmworkers and Non-farmworkers Compared

BACKGROUND

This analysis documents detections and concentrations of the six dialkylphosphate (DAP) urinary metabolite of organophosphorus (OP) pesticides among North Carolina Latino migrant farmworkers, with comparison to non-farmworker Latino immigrants.

METHODS

Participants provided up to four urine samples during the 2012 and 2013 agricultural seasons. Composite urine samples for each year were analyzed.

RESULTS

DAP urinary metabolite detections were similar in farmworkers and non-farmworker; for example, for 2012, 75.4% of farmworkers and 67.4% of non-farmworkers and, for 2013, 89.3% of farmworkers and 89.7% of non-farmworkers had dimethylthiophosphate detections. DAP geometric mean concentrations were high; for example, dimethylphosphate concentrations among farmworkers were 11.39 μg/g creatinine for 2012 and 4.49 μg/g creatinine for 2013, while they were 10.49 μg/g creatinine for 2012 and 1.97 μg/g creatinine for 2013 for non-farmworkers CONCLUSIONS:: Research to reduce pesticide exposure among Latino farmworkers and non-farmworkers is needed.

Mental Health Among Latina Farmworkers and Other Employed Latinas in North Carolina

The mental health of Latinas with manual occupations, particularly those employed in agriculture, is a public health concern. The goals of this analysis were to describe the mental health of Latina farmworkers, and to compare their mental health with that of other Latina manual workers. Participants included 35 employed Latina farmworkers, 35 employed non-farmworkers, and 25 unemployed non-farmworkers who completed interviews in 2012. Measures included stress, anxiety, depressive symptoms, elevated depressive symptoms, and risk for alcohol dependence. Farmworkers had greater stress and anxiety than did employed and unemployed non-farmworkers. Employed Latinas, whether farmworkers or in other occupations, had greater stress and anxiety than unemployed Latinas. Depressive symptoms, although high, did not differ significantly by occupation and employment. Few were at risk for alcohol dependence. Concrete steps are needed to address the mental health of Latina farmworkers, and to continue documentation of mental health concerns and their causes in this population.

Pesticide Urinary Metabolites Among Latina Farmworkers and Nonfarmworkers in North Carolina

OBJECTIVES

This paper compares detections and concentrations of pesticide urinary metabolites for Latina farmworkers and nonfarmworkers in North Carolina.

METHODS

Thirty-one farmworkers and 55 nonfarmworkers provided urine samples in 2012 and 2013. Urine samples were analyzed for detections and concentrations of organophosphate insecticide, bis-dithiocarbamate fungicide, and pyrethroid insecticide urinary metabolites.

RESULTS

Detections for several organophosphate and pyrethroid pesticide urinary metabolites were present for substantial proportions of the farmworkers and nonfarmworkers. Concentrations for several of these metabolites were high. Farmworkers and nonfarmworkers were similar in detections and concentrations for the pesticide urinary metabolites included in this analysis.

CONCLUSIONS

Participant pesticide exposure increases health risks for them and their children. Research needs to document pesticide exposure, its health effects, and ways to reduce it. Current information justifies policy development to reduce pesticide exposure in all communities.

The Association Between Skin Rashes and Work Environment, Personal Protective Equipment, and Hygiene Practices Among Female Farmworkers

The objective of this study was to assess work-related hygiene practices and the frequency and location of skin rashes due to cutaneous contact with crop-associated materials (e.g., pesticides) for female nursery and fernery workers in Central Florida. A cross-sectional, community-based participatory research study of 237 female nursery and fernery workers between the ages of 19 and 43 years with significant cutaneous contact with foliage crops was conducted using a self-report questionnaire and a skin rash chart assessment tool. Of the 237 farmworkers surveyed, 37.1% ( n = 88) reported a rash on at least one area of their bodies. Women who were pregnant during the study were 4.7 times more likely to report more than 30% total body surface area (TBSA) covered by rash compared with non-pregnant fernery workers ( p = .045; 95% confidence interval [CI] [1.04, 21.35]). Further research is needed to better understand the development of skin rashes among farmworkers, to generate effective prevention strategies.

Olfactory Function in Latino Farmworkers: Subclinical Neurological Effects of Pesticide Exposure in a Vulnerable Population

OBJECTIVES

We compared olfactory function in pesticide-exposed Latino farmworkers and nonfarmworkers to explore its use as a subclinical indicator of neurological pesticide effects.

METHODS

We recruited 304 current farmworkers and 247 nonfarmworkers. All completed odor identification (14 odors) and threshold tests (16 concentrations of n-butanol) using a well-established methodology.

RESULTS

Farmworkers reported significantly greater lifetime pesticide exposure. Performance on both olfactory tests declined with age. Odor identification performance did not differ between groups. For odor threshold, farmworkers needed significantly higher concentrations to detect the odor. Results were unchanged when adjusted for sex, age, and smoking.

CONCLUSION

Olfactory function differences between farmworkers and nonfarmworkers suggest possible neurological effects. Because declining olfactory function is an early symptom of Parkinson disease and related conditions, it is a possible subclinical indicator of neurodegenerative disease in this vulnerable worker population.

A Critical Caring Theory of Protection for Migrants and Seasonal Farmworkers

Pesticide exposures represent inequities among a vulnerable population of migrant and seasonal farmworkers. A social justice theory synthesized from an environmental health research framework, a middle range theory of critical caring, and literature on pesticide exposure is presented as a situation-specific public health practice theory. Concepts from the physiological, epistemological, vulnerability, and health protection domains are related to concepts of critical caring revealing protective strategies for vulnerable populations exposed to pesticides. The key concepts are risk exposure, community assessment, transpersonal health promotion, community competence, and controllability. Protection from exposure involves raising awareness, critically assessing communities, educating for empowerment, building capacity, and advocating to ensure social justice. Critical caring protection is provided in a mutually respectful relationship that promotes responsibility at the individual and population levels.

Longitudinal Assessment of Blood Cholinesterase Activities Over 2 Consecutive Years Among Latino Nonfarmworkers and Pesticide-Exposed Farmworkers in North Carolina

OBJECTIVE

This study (1) describes patterns of whole blood total cholinesterase, acetylcholinesterase, and butyrylcholinesterase activities across the agricultural season, comparing farmworkers and nonfarmworkers; and (2) explores differences between farmworkers' and non-farmworkers' likelihood of cholinesterase depression.

METHODS

Blood samples from 210 Latino male farmworkers and 163 Latino workers with no occupational pesticide exposure collected 8 times across 2 agricultural seasons were analyzed. Mean cholinesterase activity levels and depressions 15% or more were compared by month.

RESULTS

Farmworkers had significantly lower total cholinesterase and butyrylcholinesterase activities in July and August and lower acetylcholinesterase activity in August. Farmworkers had significantly greater likelihood of cholinesterase depression for each cholinesterase measure across the agricultural season.

SIGNIFICANCE

A repeated-measures design across 2 years with a nonexposed control group demonstrated anticholinesterase effects in farmworkers. Current regulations designed to prevent pesticide exposure are not effective.

Learning Ability as a Function of Practice: Does It Apply to Farmworkers?

OBJECTIVE

Farmworkers experience significant work-related health risks including pesticide-associated cognitive impairment. Practice effect is a surrogate for learning ability. This study examined differences in cognitive function and learning capacity in Latino farmworkers and nonfarmworkers.

METHODS

Tasks of learning and short-term memory, executive function and working memory, perceptual coding, and psychomotor function were assessed at baseline and 3-month follow-up in 136 farmworkers and 116 nonfarmworkers.

RESULTS

Farmworkers had better performance on visuospatial learning and short-term memory at baseline (P < 0.05). Nevertheless, nonfarmworkers showed more practice effects, or improvement on cognitive performance, at 3-month follow-up relative to farmworkers. Furthermore, the amount of improvement on visuospatial learning ability, short-term visuospatial memory, and perceptual coding ability was significantly higher in nonfarmworkers than in farmworkers.

CONCLUSIONS

Practice effects may serve as an additional cognitive readout to differentiate healthy individuals from those with cognitive impairment.