Exposure to fine particulate matter (PM_2.5) and pediatric rheumatic diseases

Few studies have assessed the association between fine particulate matter (PM_2.5) exposure during pregnancy and infancy and pediatric rheumatic diseases (PRDs). The goal of this study was to investigate the association of PM_2.5 with PRDs, and to explore sensitive windows of exposure. Therefore, we conducted a cohort-based case-control study to investigate the association between weekly exposure to PM_2.5 and PRDs in Taiwan. Our birth cohort consisted of infants born in 2004-2014 (n = 1,991,592) who were followed from conception to the end of 2015. There were 2363 cases of incident PRDs in children, and 23,630 children served as controls using density matching (1:10) based on date of birth, gender, and gestational week. We used a linear mixed effect (LME) model to incorporate the aerosol optical depth (AOD), meteorological variables, and land-use data to predict daily PM_2.5 concentrations. We also performed conditional logistic regression with distributed lag non-linear models (DLNMs) to assess the effects of weekly average PM_2.5 on PRDs, as well as dose-response relationships. In DLNMs, exposure to PM_2.5 during pregnancy (11-40 weeks) or infancy (1-14 weeks after birth) was associated with incident PRDs adjusting for potential confounding factors, and for carbon monoxide and sulfur dioxide. In the dose-response association, the odds ratios of PRDs were significantly increased for PM_2.5 exposures between 26 and 54 μg/m³. In addition, exposure to PM_2.5 above 81 μg/m³ dramatically increased the risk of PRDs. In conclusions, our study provides new data to suggest that PM_2.5 exposure from 11-40 gestational weeks to 1-14 weeks after birth can increase the risk for PRDs in a non-linear dose-response fashion.