Pesticide levels and absorbed doses inside Iowa homes over time: Farm families' potential long-term exposures

Background. The hazards of chronic low-level pesticide exposures inside homes, have received relatively less attention. Few studies have found that farm homes have a greater frequency of detectable pesticide concentrations and higher levels in dust and farmer's urine; however research thus far does not provide answers concerning the long-term potential bioavailability of pesticides inside homes and its risk factors. The purpose of this study was to investigate pesticide levels in Iowa homes during one year and assess the relationship between exposure levels and potential sources of pesticide contamination.; Methods. The study involved farming-based sampling surveys of the target pesticide atrazine among 32 farm families and their homes in a three-county area of Iowa. The families were surveyed during the planting season (April-June) and non-planting season (November-December). Dust samples were collected from four locations within the homes and analyzed for atrazine. Two spot-urine samples were collected from spouses and children and analyzed for atrazine and six of its metabolites. Information was gathered through questionnaires to evaluate factors affecting pesticide migration inside homes.; Results. The first study found that dust in farmers' homes was contaminated with atrazine during both seasons and these concentrations significantly decreased over a period of one year. In the second study, urine samples of all study subjects had detectable atrazine and/or its metabolites in both seasons. Mean total urinary atrazine concentrations did not significantly decrease over a period of one year. The third study found that dust concentrations of some of the four locations in the study homes were positively correlated with the total urinary atrazine levels of study subjects. A considerable number of atrazine dose estimates of farmers and their spouses were above the EPA chronic population-adjusted reference value.; Conclusions. This study found that all homes located on a farm had atrazine contamination inside them. The whole family average total urinary atrazine concentrations did not decrease over one year. The positive association of dust atrazine concentrations with total urinary atrazine concentrations indicates that the absorbed doses of atrazine are associated with the presence of atrazine in their homes.