Urinary 3, S, 6-trichloro-2-pyridinol in pregnant women from Mexico City: distribution, temporal variability, and relationship with child attention/hyperactivit

摘要

Background: Attention Deficit Hyperactivity Disorder (ADHD) is the most commonly diagnosed and studied cognitive and behavioral disorder in school-age children. The etiology of ADHD and ADHD-related behavior is unclear, but genetic and environmental factors, such as pesticides, have been hypothesized. Aims: The objective of this study was to investigate the relationship between in uteroexposure to chlorpyrifos, chlorpyrifos-methyl, and/or 3, 5, 6-trichloro-2-pyridinol (TCPY) and ADHD in school-age Mexican children. The temporal reliability of repeated maternal urinary TCPY concentrations across trimesters was also explored. Methods: From a prospective birth cohort, third trimester urinary TCPY concentrations in 187 mother-child pairs were measured. Child neurodevelopment in children 6-11 years of age was assessed using Conners' Parental Rating Scales-Revised (CRS-R), Conners' Continuous Performance Test (CPT), and Behavior Assessment System for Children-2 (BASC-2). Multivariable linear regression models were used to test relationships for all children combined and also stratified by sex. Intraclass correlation coefficients (ICC) calculations were based on a random effects model. Results: The ICC was 0.41 for uncorrected TCPY, and ranged from 0.29 to 0.32 for specific gravity-corrected TCPY. We did not observe any statistically significant associations between tertiles of maternal TCPY concentrations and ADHD-related outcomes in children, however, we found suggestive evidence of effect modification by sex for ADHD in boys (β= 5.55 points; 95% CI(-0.19,11.3); p=0.06) and attention problems in girls (β=5.81 points; 95% CI(-0.75,12.4); p=0.08). Conclusions: Considering the continued widespread agricultural and possible residential use of chlorpyrifos and chlorpyrifos-methyl in Mexico and the educational implications of cognitive and behavior deficits, these results are important and deserve further study.