Mapping pesticide exposure routes

Combining modeling with biomonitoring data reveals pesticide exposure routes in pregnant Latina women in the Salinas Valley (Calif.).

Thomas McKone and his co-workers set out to answer a simple question: can the levels of pesticides in pregnant women in the Salinas Valley (Calif.) be correlated with the amounts of these chemicals used in surrounding farmlands? A simple statistical model suggested no direct correlation, but McKone and his colleagues at the Lawrence Berkeley National Laboratory and the University of California, Berkeley, didn't stop there.

The team combined multiple fate and exposure models with biomonitoring data. The results, published today on ES&T's Research ASAP website (DOI: 10.1021/es0618447), show that the study population has a significantly higher intake of organophosphorus (OP) pesticides than the average woman in the same age group.

 

McKone and his team studied OP pesticide exposure in about 600 pregnant Latina women in the Salinas Valley. They were all part of a larger study on women and children's environmental health, called the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) project. The concentration of the pesticide metabolites in the CHAMACOS population was compared with the average levels in women from across the U.S. (from data collected by the National Health and Nutrition Examination Survey, or NHANES, in 1999–2000). This revealed that the Salinas Valley women are being exposed to "significantly higher" levels of the pesticides, says McKone.

Few studies "include how much [of a contaminant] is actually reaching us as organisms and how this results in concentrations in our tissue and fluids," adds MacKay. This study provides "a shining example of the approach that should be taken for more substances, including pesticides and industrial chemicals. If that can be done, it will help the whole risk assessment process enormously."—RHITU CHATTERJEE