Immunotoxic effects in children resulting from prenatal and early childhood exposure to pesticides: A systematic review and meta-analysis.

Pesticide exposure during critical developmental windows may have lasting effects on the immune system. This systematic review examines the evidence for immunotoxic effects in children resulting from prenatal and early childhood exposure to pesticides. The review followed the PRISMA 2020 guidelines. A comprehensive search of scientific literature was conducted to identify studies examining associations between pesticide exposure and immune system parameters in children. Seventeen studies met the inclusion criteria. The reviewed studies consistently demonstrated alterations in immune parameters following pesticide exposure, with particular effects on white blood cell populations, cytokine production, and clinical outcomes. Meta-analyses revealed significant reductions in neutrophil counts (effect size: -0.09, 95 % confidence interval (CI): -0.17, -0.01; p = 0.02) and eosinophil counts (effect size: -0.06, 95 % CI: -0.09, -0.03; p < 0.001). Pro-inflammatory cytokine production was significantly increased (effect size: 0.18, 95 % CI: 0.08, 0.28; p < 0.001), while mixed pesticide exposure showed elevated immunoglobulin responses (odds ratio (OR): 1.42, 95 % CI: 1.12, 1.80; p < 0.001). Prenatal exposure to organochlorine pesticides was associated with decreased lymphocyte counts, altered T-cell subpopulations, dysregulated cytokine production, and increased susceptibility to infections. Pesticide exposure was linked to both immunosuppression and pro-inflammatory/allergic responses, suggesting complex and potentially exposure-specific effects. This review provides evidence that prenatal and early childhood pesticide exposure is associated with measurable changes in immune system parameters. These alterations may have clinical implications for childhood infections, allergic diseases, and potentially autoimmune conditions. Further research with standardized exposure and outcome assessments is needed to better characterize exposure-response relationships and identify specific vulnerable periods of immune system development.