Ability to trace migrant farmworkers ten years after initial identification in a Northern State (Wisconsin)

Studying health outcomes in farmworker populations exposed to pesticides

A major goal of studying farmworkers is to better understand how their work environment, including exposure to pesticides, affects their health. Although a number of health conditions have been associated with pesticide exposure, clear linkages have yet to be made between exposure and health effects except in cases of acute pesticide exposure. In this article, we review the most common health end points that have been studied and describe the epidemiologic challenges encountered in studying these health effects of pesticides among farmworkers, including the difficulties in accessing the population and challenges associated with obtaining health end point data. The assessment of neurobehavioral health effects serves as one of the most common and best examples of an approach used to study health outcomes in farmworkers and other populations exposed to pesticides. We review the current limitations in neurobehavioral assessment and strategies to improve these analytical methods. Emerging techniques to improve our assessment of health effects associated with pesticide exposure are reviewed. These techniques, which in most cases have not been applied to farmworker populations, hold promise in our ability to study and understand the relationship between pesticide exposure and a variety of health effects in this population. Key words: biomarkers, cancer, epidemiology, health outcomes, immigrants, neurobehavioral, neuropathy, pesticides.

National farmworker database: establishing a farmworker cohort for epidemiologic research

BACKGROUND

There is little research into the long-term health effects of pesticides and other agricultural exposures among seasonal and migrant farmworkers in the United States. We present results of a feasibility study that established a cohort of farmworkers for use in epidemiologic research.

METHODS

Subjects consisted of migrant and seasonal farmworkers who joined the cohort while seeking social services through members of the Association of Farmworker Opportunity Programs (AFOP) and were entered in the National Farmworker Database (NFD) between the end of 1997 and March 1999. We designed an add-on interview with information that enhanced the utility of the database for epidemiologic research.

RESULTS

We recruited and obtained basic demographic and employment information on 5,597 farmworkers at very modest cost and effort. Subjects were mostly seasonal (61.5%), female (56.7%), and Hispanic (67.4%), with a median age of 27. Most (62.6%) had not completed high school; almost all (99.1%) reported being U.S. citizens or permanent residents, an eligibility requirement for some of the services provided by AFOP. The majority (62.5%) had engaged in farmwork for less than 10 years, but had performed a wide variety of tasks on different crops, including row crops and tree fruits. Picking was the most common task reported. Most subjects had performed farmwork in Florida, North Carolina, Texas, Michigan, or Georgia. For usual source of health care, 63.7% reported use of U.S. hospitals or emergency rooms/clinics, 42.0% U.S. private physicians, and 29.7% migrant health clinics. Among subjects reporting a prior diagnosis of cancer, primary sources of health care for treatment of that cancer included U.S. private physicians (61.9%), U.S. hospitals or emergency rooms/clinics (23.8%), and migrant health clinics (10.5%).

CONCLUSIONS

Results suggest that by adding a brief interview to the existing NFD data collection process, which was designed for other purposes, it is feasible to create an efficient tool for conducting longitudinal epidemiologic research among farmworkers.