Behavioral observation used to estimate pesticide exposure for farm workers in Brazil

Assessment of the harm caused by exposure to pesticides requires that a measure of exposure be available. While such information is available without difficulty in controlled laboratory studies, estimating the exposure of humans who have been exposed in the real world is difficult. The difficulty is increased if exposures have taken place over an extended time period and the documentation of specifics is unavailable. Three methods of exposure assessment have previously been used: comparison of exposed and non-exposed groups, estimation of exposures through self-report of the individuals, and estimation of exposure through assessment of biomarkers or environmental levels. Each approach imposes limitations. We propose an additional approach - estimation of the degree of exposure for individuals through direct observation of their behavior and their use of personal protective equipment (PPE) during periods of exposure. We also obtain opinions from experts regarding the risk associated with the various behaviors and PPE use and combine these with the observations to create a personal risk index for each individual. By including information on chemicals in use during this period, we can characterize recent (observed) exposure for that individual. By these steps, the degree of risk may be determined for recent (observed) exposure. An estimate of long-term risk resulting from work-related exposures can be obtained for individuals by summing across their work histories.

Behavioral observation used to estimate pesticide exposure for farm workers in Brazil

Assessment of the harm caused by exposure to pesticides requires that a measure of exposure be available. While such information is available without difficulty in controlled laboratory studies, estimating the exposure of humans who have been exposed in the real world is difficult. The difficulty is increased if exposures have taken place over an extended time period and the documentation of specifics is unavailable. Three methods of exposure assessment have previously been used: comparison of exposed and non-exposed groups, estimation of exposures through self-report of the individuals, and estimation of exposure through assessment of biomarkers or environmental levels. Each approach imposes limitations. We propose an additional approach - estimation of the degree of exposure for individuals through direct observation of their behavior and their use of personal protective equipment (PPE) during periods of exposure. We also obtain opinions from experts regarding the risk associated with the various behaviors and PPE use and combine these with the observations to create a personal risk index for each individual. By including information on chemicals in use during this period, we can characterize recent (observed) exposure for that individual. By these steps, the degree of risk may be determined for recent (observed) exposure. An estimate of long-term risk resulting from work-related exposures can be obtained for individuals by summing across their work histories.(AU)

Assessing the association between pesticide exposure and cognitive development in rural Costa Rican children living in organic and conventional coffee farms.

We examined the association between pesticide exposure and cognitive development among rural Costa Rican children in a cross-sectional study. Study participants aged 4-10 years included 17 children whose parents worked in La Amistad organic coffee plantation and 18 Las Mellizas children whose parents worked in their own small conventional coffee farms. Two spot-urine samples were collected from each participant and analyzed for organophosphorus and pyrethroids pesticide metabolites. We administered the computerized Behavioral Assessment and Research System (BARS), a figure-drawing task, and a long-term memory test to evaluate study participant's cognitive development. Although urinary pesticide metabolite levels did not vary considerably between these two groups of children, we found that Las Mellizas children performed better in BARS and the figure drawing tests than did La Amistad. The results from the linear mixed-effects models suggested that family socioeconomic status (SES) might be a significant contributor to the variation of the outcomes of the neurobehavioral tests. The effect of pesticide exposure, however, as measured in a snapshot fashion, did not play a significant role to the performance of the cognitive development evaluation. Regardless of the study limitations, needed effort should be devoted to the improvement of the SES on the La Amistad families so that their children's cognitive development would not be compromised further. Additionally, future studies should focus on addressing the limitations imposed on the snapshot assessment of pesticide exposure and on conducting cognitive development evaluation so the link between childhood pesticide exposure and their cognitive development can be thoroughly investigated.