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

Background Migrant and seasonal farmworkers are exposed to pesticides throu gh their work with crops and livestock. Because workers are usually unaware of the pesticides applied, specific pesticide exposures cannot be determin ed by interviews. We conducted a study to determine the feasibility of iden tifying probable pesticide exposures based on work histories. Methods The study included 162 farm workers in seven states. Interviews obt ained a lifetime work history including the crops, tasks, months, and locat ions worked. We investigated the availability of sun,ey data oil pesticide use for crops and livestock in the seven pilot states. Probabilities of use for pesticide types (herbicides, insecticides, fungicides, etc.) and speci fic chemicals were calculated from the available data for two farm workers. The work histories were chosen to illustrate how the quality of the pestic ide use information varied across crops, states, and years. Results For most vegetable and fruit crops there were regional pesticide us e data ill the late 1970s, no data in the 1980s, and state-specific data ev ery other year in the 1990s. Annual use surveys for cotton and potatoes beg an in the late 1980s. For a few crops, including asparagus, broccoli, lettu ce, strawberries, plums, and Christmas trees, there were no federal data or data from the seven states before the 1990s. Conclusions We conclude that identifying probable pesticide exposures is fe asible ill some locations. However, the lack of pesticide use data before t he 1990s for many crops will limit the quality of historic exposure assessm ent for most workers. Published 2001 Wiley-Liss, Inc.