Determining the probability of pesticide exposures among migrant farmworkers: results from a feasibility study

Farmers' Exposure to Pesticides: Toxicity Types and Ways of Prevention

Synthetic pesticides are extensively used in agriculture to control harmful pests and prevent crop yield losses or product damage. Because of high biological activity and, in certain cases, long persistence in the environment, pesticides may cause undesirable effects to human health and to the environment. Farmers are routinely exposed to high levels of pesticides, usually much greater than those of consumers. Farmers’ exposure mainly occurs during the preparation and application of the pesticide spray solutions and during the cleaning-up of spraying equipment. Farmers who mix, load, and spray pesticides can be exposed to these chemicals due to spills and splashes, direct spray contact as a result of faulty or missing protective equipment, or even drift. However, farmers can be also exposed to pesticides even when performing activities not directly related to pesticide use. Farmers who perform manual labor in areas treated with pesticides can face major exposure from direct spray, drift from neighboring fields, or by contact with pesticide residues on the crop or soil. This kind of exposure is often underestimated. The dermal and inhalation routes of entry are typically the most common routes of farmers’ exposure to pesticides. Dermal exposure during usual pesticide handling takes place in body areas that remain uncovered by protective clothing, such as the face and the hands. Farmers’ exposure to pesticides can be reduced through less use of pesticides and through the correct use of the appropriate type of personal protective equipment in all stages of pesticide handling.

Household and occupational exposure to pesticides and risk of breast cancer

The association between breast cancer in women and the use of household or occupational pesticides was examined in a population-based case-control study. This study was conducted in Western Australia in 2009-2011 and included 1,789 controls and 1,205 cases. Information on household pesticide exposure was collected from questionnaires. For occupational pesticide exposure, job-specific modules (JSMs) were used. To evaluate potential recall bias, we stratified the analysis by belief about whether pesticides contribute to breast cancer. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Women's exposures to pesticides in households and workplaces were not related to increased risk of breast cancer (OR = 1.10; CI: 0.86-1.37) and (OR = 0.77; CI: 0.45-1.32), respectively. The prevalence of occupational exposure to pesticides among women in our study was low. In the stratified analyses, the odd ratios associated with household pesticide use were similar among participants who believed pesticides increased breast cancer risk and those who did not. The results of our study did not show associations between breast cancer and household or occupational exposure to pesticides.

Dermal exposure associated with occupational end use of pesticides and the role of protective measures

BACKGROUND

Occupational end users of pesticides may experience bodily absorption of the pesticide products they use, risking possible health effects. The purpose of this paper is to provide a guide for researchers, practitioners, and policy makers working in the field of agricultural health or other areas where occupational end use of pesticides and exposure issues are of interest.

METHODS

This paper characterizes the health effects of pesticide exposure, jobs associated with pesticide use, pesticide-related tasks, absorption of pesticides through the skin, and the use of personal protective equipment (PPE) for reducing exposure.

CONCLUSIONS

Although international and national efforts to reduce pesticide exposure through regulatory means should continue, it is difficult in the agricultural sector to implement engineering or system controls. It is clear that use of PPE does reduce dermal pesticide exposure but compliance among the majority of occupationally exposed pesticide end users appears to be poor. More research is needed on higher-order controls to reduce pesticide exposure and to understand the reasons for poor compliance with PPE and identify effective training methods.

A community intervention to decrease antibiotics used for self-medication among Latino adults

PURPOSE

Recent evidence in Latino communities indicates substantial self-medication with antibiotics obtained without a prescription (WORx). We implemented and evaluated a culturally sensitive educational intervention to decrease antibiotic self-medication.

METHODS

We conducted a community-based intervention with preintervention and postintervention measures in the intervention community (Charleston, South Carolina) as well as a postintervention measure in a control community (Greenville, South Carolina) 200 miles away. The 9-month culturally sensitive intervention included multiple media sources (pamphlets, radio, newspapers). We evaluated the use of antibiotics WORx in the United States, as well as the likelihood of importing antibiotics, by surveying Latino adults in the intervention (n = 250) and in the control community (n = 250).

RESULTS

Most adults in the intervention community (69%) and the control community (60%) reported some exposure to messages about the inappropriate use of antibiotics, and 25.9% in the intervention community and 8.6% in the control community reported seeing our patient education pamphlets. A substantial proportion of Latino adults in both the intervention (31%) and control communities (20%) have obtained antibiotics WORx in the United States. In multivariate analyses, exposure to an educational message was not a significant predictor of having acquired antibiotics WORx in the United States in past 12 months. The primary predictor of respondents' having acquired antibiotics WORx in the United States was whether they had bought antibiotics WORx outside the United States.

CONCLUSIONS

Novel approaches are needed to decrease the use of antibiotics WORx in Latino communities, as focusing only on education may not be sufficient to change behaviors common in their home countries.

Exposure profiles of pesticides among greenhouse workers: implications for epidemiological studies

The aim of this study was to assess exposure to pesticides for a longitudinal epidemiological study on adverse reproduction effects among greenhouse workers. Detailed information on pesticide use among greenhouse workers was obtained on a monthly basis through self-administered questionnaires and subsequent workplace surveys. Questionnaires were filled in for a whole year. Dermal exposure rankings were developed for each task using the observational method Dermal Exposure Assessment Method (DREAM). Exposure scores were calculated for each worker for each month during the year, taking into account frequency, duration and exposure intensity for each task. A total number of 116 different active ingredients were used in the population, whereas a mean number of 15 active ingredients were applied per greenhouse. DREAM observations provided insight into the exposure intensity of 12 application techniques and three mixing and loading activities. Relatively high DREAM scores were obtained for scattering, fogging, dusting, and mixing and loading of powders. Observations with DREAM indicated that application with a horizontal ground-boom, motor driven boom, and bulb shower resulted in low dermal exposure. Exposure scores showed substantial variation between workers and over the year. It can be concluded that exposure variation between- and within greenhouses is very large, both in terms of chemical composition and exposure intensity. This may be a significant contributor to the inconsistent results of studies evaluating health effects of pesticide exposure.

Current practices in spatial analysis of cancer data: data characteristics and data sources for geographic studies of cancer

The use of spatially referenced data in cancer studies is gaining in prominence, fueled by the development and availability of spatial analytic tools and the broadening recognition of the linkages between geography and health. We provide an overview of some of the unique characteristics of spatial data, followed by an account of the major types and sources of data used in the spatial analysis of cancer, including data from cancer registries, population data, health surveys, environmental data, and remote sensing data. We cite numerous examples of recent studies that have used these data, with a focus on etiological research.

Assessment of occupational health and safety risks of farmworkers in Colorado

BACKGROUND

Migrant farmworkers face a variety of hazards including exposure to pesticides and agricultural chemicals. However, few studies have quantatively evaluated these risks.

METHODS

Hazards were assessed during 32 field surveys conducted in the agricultural fields and 15 surveys at five camps. Observations of 1,461 farmworkers for potential hazards were recorded. Estimated risk was evaluated on a four-point scale (no hazard, minor, serious, and critical). A total of 229 farmworkers were interviewed about field conditions.

RESULTS

Two out of the five camps did not have safe drinking water. Risks for farmworkers were lower when a manager was living on site. Field surveys estimated higher risk when provision of sanitation was deficient (P < 0.05). Farmworkers' responses concerning field conditions differed from the survey findings.

CONCLUSIONS

Risks for farmworkers depended largely on the environment provided. Discordances between survey results and farmworkers' interview responses suggested that self-reported data might have limited validity for this population. Working and living conditions require improvement to decrease occupational risks for farmworkers.

Prenatal exposure to pesticides: a feasibility study among migrant and seasonal farmworkers

BACKGROUND

Migrant and seasonal farmworkers have a high potential for pesticide exposures, yet are rarely included in epidemiologic studies. This study examined the feasibility of assessing prenatal exposures to pesticides and other compounds in pregnant Hispanic farmworkers.

METHODS

Nine women completed a survey about work experiences during pregnancy. Maternal urine, cord blood, and placenta samples were obtained at delivery for analysis of 51 analytes, including 6 phenoxy acid or triazine herbicides, 21 organochlorine insecticides, 10 PCBs, and 14 volatile organic compounds.

RESULTS

Seven of 51 analytes were found in the biological samples. DDE, DDT, dichlorbenzene, toluene, trimethylbenzene, and endosulfan sulfate were detected in cord blood samples, and 2,4-D in urine from one or more women.

CONCLUSIONS

We documented the feasibility of following farmworkers to assess in utero exposure to pesticides and other contaminants, and demonstrated exposure to these compounds. Difficulties in measuring pesticides with short half lives were noted.

Development of a life events/icon calendar questionnaire to ascertain occupational histories and other characteristics of migrant farmworkers

BACKGROUND

Specialized methods are necessary to collect data from migrant farmworkers for epidemiologic research.

METHODS

We developed a questionnaire that collected lifetime occupational histories and other lifestyle risk factors via a life events/icon calendar, and administered the questionnaire to a convenience sample of 162 migrant farmworkers in nine areas of the U.S.

RESULTS

The average duration of the interviews was about 1 h 30 min, with an average of 45 min for the work history section. The occupational histories covered a median of 27.6 years per person for men and 20.8 years per person for women. The median number of years spent in farm jobs was 11.3 for men and 5.8 for women. The median number of farm jobs (crop/task combination) per person was 59 among men and 27 among women. Many farmworkers performed the same crop/task combinations at multiple times throughout their lives, yielding a median of 13 unique farm jobs and 8 unique crops among men and 7 jobs and 5 crops among women.

CONCLUSIONS

The project demonstrated that it is feasible to collect detailed work histories and other risk factor data from farmworkers, documented the complexity of work histories encountered among farmworkers, and yielded recommendations for refining a questionnaire that will facilitate future epidemiologic research on farmworkers.

A method for assessing occupational pesticide exposures of farmworkers

BACKGROUND

The health of farmworkers as related to pesticide exposure is of concern but assessing exposures for epidemiologic studies requires different techniques than approaches used for studies of industrial workers.

METHODS

A review of the literature identified possible factors that affect exposure intensity. A model was developed to estimate an exposure score. Exposures in the literature were estimated using the model and compared to the measurements in the literature.

RESULTS

Three studies were found with information appropriate for evaluation of the model. There was a statistical difference between the means of the scores corresponding to above and below the median of the measurements. The correlation coefficient between the scores and the measurements from the literature was 0.77.

CONCLUSIONS

Although the evaluation was limited, the model appeared to work well, but more testing is needed. More research is also needed to increase understanding of what affects the exposures of these workers.