New studies on pesticides

Environmental Health Perspectives, the peer-reviewed open access journal published by the National Institute of Environmental Health Science, USA, has released new studies. One of them is the "7-Year Neurodevelopmental Scores and Prenatal Exposure to Chlorpyrifos, a Common Agricultural Pesticide“. On average, for each standard deviation increase in exposure (4.61 pg/g), Full-Scale IQ declined by 1.4 %, and Working Memory declined by 2.8 %. Final covariates included maternal educational level, maternal IQ, and quality of the home environment. There were no significant interactions between CPF and any covariates, including the other chemical exposures measured during the prenatal period (environmental tobacco smoke and polycyclic aromatic hydrocarbons). The document is available here .

The study "Prenatal Exposure to Organophosphates, Paraoxonase 1, and Cognitive Development in Childhood" was also published. The relationship between biomarkers of organophosphate exposure, PON1, and cognitive development at ages 12 and 24 months, and 6 to 9 years was examined. Prenatal total dialkylphosphate metabolite level was associated with a decrement in mental development at 12 months among blacks and Hispanics. These associations appeared to be enhanced among children of mothers who carried the PON1 Q192R QQ genotype, which imparts slow catalytic activity for chlorpyrifos oxon. In later childhood, increasing prenatal total dialkyl- and dimethylphosphate metabolites were associated with decrements in perceptual reasoning in the maternal PON1 Q192R QQ genotype, with a monotonic trend consistent with greater decrements with increasing prenatal exposure. The report is available here .

A further study is also available now: "Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Year Old Children" The objective was to examine associations between prenatal and postnatal exposure to OP pesticides and cognitive abilities in school-age children. Urinary DAP concentrations measured during the 1st and 2nd half of pregnancy had similar relations to cognitive scores, thus the average of concentrations measured during pregnancy in further analyses was used. Averaged maternal DAP concentrations were associated with poorer scores for Working Memory, Processing Speed, Verbal Comprehension, Perceptual Reasoning, and Full Scale IQ. Children in the highest quintile of maternal DAP concentrations had an average deficit of 7.0 IQ-points compared with those in the lowest quintile. However, children’s urinary DAP concentrations were not consistently associated with cognitive scores.