Impact of Endocrine Disruptive Chemicals on the Developing Immune System: Consequences for Child Respiratory and Allergic Disorder

Abstract

An alarming trend is evident with the increasing prevalence of respiratory and allergic diseases among children globally. This surge in prevalence might be linked to early-life exposure to endocrine-disrupting chemicals (EDCs). Prenatal exposure to EDCs could disrupt the developing immune system, potentially diminishing the ability to combat infections and increasing the risk of developing respiratory and allergic manifestations in later life. This review aims to consolidate epidemiological evidence on the adverse effects of prenatal exposure to diverse EDCs on the development of respiratory and allergic disorders in children, along with an exploration of potential underlying biological mechanisms. To achieve this, a literature search was conducted between November 2023 and January 2024 in PubMed and Google Scholar, using combined search terms related to EDC exposure during pregnancy and child respiratory and allergic outcomes. Numerous studies suggest a positive correlation between prenatal exposure to pesticides, polychlorinated biphenyls, phthalates, and polycyclic aromatic hydrocarbons, and the manifestation of respiratory and allergic disorders in children. However, notable inconsistencies persist, making the establishment of a clear relationship challenging. The standardized methodology for outcome assessment enhances comparability across studies, yet the heterogeneity in the timing of exposure and outcome assessments currently poses challenges for comparisons. Additionally, the exact biological mechanisms underlying the studied outcomes associated with prenatal exposure to EDCs remain largely unknown. Recommendations for a more comprehensive understanding include the harmonization of exposure and outcome assessment methodologies, improving characterization of respiratory and allergic disorders in children and incorporating long-term assessment of both exposure and outcomes to gain insights into the window of susceptibility. Additionally, in vitro experiments must be performed to examine underlying biological mechanisms and analysis of EDC mixtures and low-dose exposures should be incorporated.