Urinary Metabolites of Organophosphate and Pyrethroid Pesticides and Neurobehavioral Effects in Chinese Children

Organophosphate (OP) and pyrethroid (PYR) pesticides are widely used in China. However, few studies have investigated the neurobehavioral outcomes of Chinese children exposed to low levels of OP and PYR. We investigated urinary metabolite levels and their association with exposure characteristics and the neurobehavior of children. For all children, biomarker measurements were made in the same interval relative to neurobehavioral testing. We analyzed the morning urine samples of 406 children aged 3-6 years from Nanjing, China. The Kruskal-Wallis and Wilcoxon rank sum tests were used to identify the associations between urinary metabolite levels and exposure characteristics. Multiple linear regression models were used to test the associations between urinary metabolite levels and neurobehavioral test scores after adjusting for covariates (e.g., sex, age, and education expense). The detection of 3,5,6-trichloropyridinol (TCP) and 3-phenoxybenzoic acid (3-PBA) in the urine was positively associated with living areas adjacent to agricultural fields and using indoor mosquito repellent incense. These two metabolites were negatively associated with the soaking time of fruits and vegetables. When treated as dichotomous variables, TCP was significantly associated with arithmetic test scores in adjusted models, and 3-PBA was significantly associated with the scores on the Chinese Binet and arithmetic tests. When treated as a continuous variable, higher urinary 3-PBA levels were significantly associated with lower cancellation test scores. Our findings suggest that exposure to organophosphate and pyrethroid pesticides may have a significant impact on children's working memory and verbal comprehension.