Organophosphates (OP) are a class of pesticides that are well-known neurotoxicants. Indoor use of chlorpyrifos and diazinon, two common OP pesticides, has been phased out over the past decade, primarily because of health risks to children.
The 329 children in the UC Berkeley study had been followed from before birth as part of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), an ongoing longitudinal study led by Eskenazi. The new findings on IQ come less than a year after another study from the CHAMACOS cohort found an association between prenatal pesticide exposure and attention problems in children at age 5.
Researchers began enrolling pregnant women in the study in 1999. During pregnancy and after the children were born, study participants came to regular visits where CHAMACOS staff administered questionnaires and measured the health and development of the children.
During the visits, samples of urine were taken from the participants and tested for dialkyl phosphate (DAP) metabolites, the breakdown product of about 75 percent of the organophosphorus insecticides in use in the United States. Samples were taken twice during pregnancy, with the two results averaged, and after birth from the children at regular intervals between ages 6 months and 5 years.
The Wechsler Intelligence Scale for Children Fourth Edition (WISC-IV) was used to assess the cognitive abilities of the children at age 7. The test includes subcategories for verbal comprehension, perceptual reasoning, working memory and
|Contact: Sarah Yang|
University of California - Berkeley