D3.387 - The association of early-life urban chemical exposures and cytokines in Thai infants: evidence from a pilot birth cohort study

Rapid urbanisation and industrialisation have led to increased chemical pollution, raisingconcerns about its potential effects on infant immune development and allergic responses. This sub-analysis of a prospective cohort study examined the association between early-life exposure to urban environmental pollutants and immune system alterations in Thai infants.

A pilot cohort study recruited first-trimester pregnant women and their infants from Ramathibodi, Samut Prakan, and Rayong Hospitals in Thailand. Targeted urbanchemical pollutants were assessed, including ambient PM_2.5 exposure estimated by spatialinterpolation of reported concentrations and biomarkers measured in biological samples. Whole blood heavy metal concentrations (As, Cd, Cr, Hg, Mn, and Pb) were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the first trimester, while urine cotinine/creatinine ratio (CCR) was assessed across pregnancy and infancy (early-life). Infantcytokine levels were measured at 6–12 months of age. Due to the non-normal distribution of data, the Spearman correlation was used to determine associations between chemical exposure and cytokine concentrations.

Among 203 pregnant women enrolled, 86 maternal-child pairs were included in the analysis. Spearman correlation analysis identified significant positive and negative associations between infant cytokine concentrations (Interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, IL-22, IL-31, IL-33, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, andthymic stromal lymphopoietin (TSLP)) and exposure to various heavy metals (excluding Cd and Pb), urine CCR, and PM_2.5.

Early-life exposure to urban environmental pollutants is associated with cytokine alterations in Thai infants. Further research is needed to explore the clinical implications of these findings, particularly concerning allergy development and immune dysfunction.