Cognitive deficits in organophosphate exposed children of Nicaraguan subsistence farmers
(English)Manuscript (preprint) (Other academic)
Objective: This study examined cognitive and behavioral performance among school-age children in Nicaragua in relation with long-term and recent organophosphate exposures.
Methods: Long-term organophosphate was assessed in 110 children aged 7-9 through a parental use index of kg of organophosphate during de pregnancy, first year of life and from 1 year old to the present. Recent exposure was determined in a subset of 74 children by urinary 3,5,6-trichloro-2-pyridinol (TCPY) levels. Cognitive function was evaluated with Wechsler Intelligence Scale for Children (WISC IV), total IQ and subtests grouped into indices for perceptual reasoning, verbal comprehension, working memory, and processing speed. Behavior at school was measured with the Conners’ Teacher Rating Scale-Revised:Short (CTRS-R:S). Multivariate linear regression models assessed adjusted associations.
Results: For each 10-fold increase in prenatal indices for total OP use, children’s performance on working memory significantly decreased with 3.5 points, and similarly for chlorpyrifos and methamidophos. Prenatal methamidophos use was, in addition, significantly associated with poorer verbal comprehension and decrease in total IQ, a 10-fold use increase decreasing scores with 3.8 and 3.3 points respectively. Urinary TCPY (mg/g of creatinine) also affected, not significantly, working memory with a 3.2 point decrease for each 10-fold increase. This study did not find associations between postnatal organophosphate use indices and cognitive performance, or pre or postnatal use indices with behavior.
Conclusion: Prenatal exposure to organophosphates decreased the cognitive abilities in Nicaraguan children, particularly in working memory. Methamidophos was also associated with poor verbal comprehension and total IQ.
organophosphates, children, pesticide, cognitive function, behavior, neurodevelopment
Medical and Health Sciences
Research subject Occupational and Environmental Medicine; Epidemiology
IdentifiersURN: urn:nbn:se:uu:diva-182148OAI: oai:DiVA.org:uu-182148DiVA: diva2:558603