The silent impact of pesticides: A systematic and critical review of endocrine disruption, FOXP2, and language development

The rising global utilization of pesticides, organophosphates and pyrethroids, has elicited significant apprehensions regarding their possible effects on neurodevelopment, particularly in relation to language acquisition. Pesticides are acknowledged as endocrine-disrupting chemicals (EDCs); however, their precise impact on the hormonal regulation of FOXP2, a gene crucial for vocal learning and expressive language, has not been thoroughly investigated. This study seeks to systematically and critically analyze the correlation between pesticide exposure, testosterone levels, FOXP2 gene expression, and language-related outcomes, emphasizing sex-specific susceptibility. In accordance with PRISMA guidelines, 23 peer-reviewed empirical studies published from 2003 to 2024 were chosen from Scopus, PubMed, Web of Science, and ScienceDirect. A mixed-methods synthesis was executed across three domains: endocrine disruption, hormonal modulation of FOXP2, and behavioral-linguistic ramifications. The quality of the study was assessed with the ROBINS-I and SYRCLE tools, and the certainty of the evidence was assessed with a GRADE-style framework. The findings indicate that pesticide exposure is consistently linked to diminished testosterone levels, which subsequently downregulate FOXP2 expression in brain regions essential for speech. Changes in FOXP2 expression are linked to problems with expressive language and phonological errors in both humans and animals. The review differentiates between clinical impairments and subclinical variations, emphasizing limited yet significant sex-specific effects. These findings highlight the necessity for longitudinal, sex-sensitive research and enhanced public health policies to reduce developmental risks. Comprehending the impact of environmental toxins on language development is crucial for early intervention and the protection of neurocognitive outcomes.