Exposição pré e pós-natal a agrotóxicos e seu impacto no desenvolvimento neuroendócrino em crianças aos 12 meses de idade: Um estudo de coorte no Recôncavo Baiano

Abstract

Neurodevelopment (ND) is susceptible to the influence of several external factors, including pesticides. Their widespread use on a global scale has raised growing concerns about their impacts on environmental and human health, especially in vulnerable populations such as pregnant women and children. Many of these compounds are known endocrine disruptors with potential to harm children's ND. The aim of this study was to evaluate pre- and postnatal exposure to pesticides and their endocrine and ND effects in children in a region of Recôncavo Baiano, Brazil. Initially, we conducted a systematic review on exposure to glyphosate (GLY), one of the most widely used herbicides in the region, and its impact on child and animal neurodevelopment. We reviewed fourteen original articles, twelve of which were experimental and two epidemiological. The epidemiological studies did not determine GLY concentrations, they only performed mathematical estimates of exposure, and none of them were conducted in Brazil. Although animal studies have demonstrated deficits in neurological development, further research is still needed to fully understand the impact of GLY on infant ND, especially in epidemiological studies. We subsequently assessed the panorama of exposure to pesticide residues in pregnant women and their infants, measuring parent molecules in serum samples by HPLC-MS/MS. Those with importance in endocrine and neurocognitive health were highlighted, and we assessed food frequency during pregnancy as a way to estimate exposure to certain agents based on values reported in an ANVISA assessment. We detected pesticides in 4.7% of pregnant women and in 27.6% of infants. Lufenuron was the most frequent pesticide detected in children. We hypothesize that this exposure is via the dermal route due to contact with pets treated for ectoparasites. Regarding pregnant women, monocrotophos, tebuconazole, tricyclazole and vamidothion were detected in smaller proportions. Finally, we explored the associations between thyroid hormone concentrations and infant DN. Serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and total triiodothyronine (TT3) were analyzed in pregnant women and children at an average age of 19 months. The Bayley Scales of Infant and Youth Development, 3rd edition (BSID-III) was applied to assess ND. The following values were within normal limits: 90.9% of TSH, 54.5% of TT3, and 77.3% of FT4 in pregnant women; while in children they were 92.4%, 97.0%, and 16.7%, respectively. High FT4 levels, still within normal limits, in children were associated with improvements in motor skills, particularly among boys. TT3 concentrations in pregnant women were positively correlated with language performance, while TSH levels were inversely correlated with language development. Finally, we also observed a non-linear association between TSH levels in children and motor development. Taken together, this work provides an assessment of the associations between pesticide exposure, maternal and child thyroid function, and ND. The results highlight the importance of maternal thyroid health during pregnancy, considering its influence on child ND. The detection of pesticides with endocrine disrupting properties and deleterious effects on ND underscores the urgent need for targeted interventions, continuous monitoring, and further research to protect the most vulnerable populations and deepen the understanding of these complex interactions.