Minsun Lee, Kyungjun Jeong, Kyungnam Kim, Jaelim Cho, Dae Ryong Kang, Myung Hyun Sohn, Yongjin Lee, Changsoo Kim
Short-term exposure to ambient VOC mixtures, particularly aromatics, is associated with an increased pediatric burden of AD and asthma in Seoul. Toluene was identified as a key contributor, whereas the roles of other VOCs require further investigation because of potential shared source contributions with other pollutants.
BACKGROUND: Ambient volatile organic compounds (VOCs) exist as complex mixtures. Their short-term health associations in children remain poorly characterized.
OBJECTIVE: To evaluate short-term associations between ambient VOC mixtures and pediatric atopic dermatitis (AD) and asthma in Seoul, Korea, and to estimate the ecological attributable burden.
METHODS: Daily counts of outpatient visits and hospital admissions among individuals aged <19 years in Seoul (2015-2019) were linked with citywide VOC concentrations grouped as n-alkanes (G1), branched/cyclo-alkanes (G2), alkenes/alkynes (G3), and aromatics (G4). Mixture associations were estimated using Weighted Quantile Sum regression (WQSR) and Bayesian Kernel Machine Regression. Population Attributable Fractions (PAFs) were calculated from WQSR-based relative risks under a hypothetical 25th-percentile lower-exposure scenario.
RESULTS: Ambient VOC mixtures were associated with higher daily counts of outpatient visits and hospital admissions for pediatric AD and asthma. Toluene (G4) showed the highest WQSR weight (0.88 for AD; 0.75 for asthma), while hexane (G1) and cyclohexane (G2) also showed relatively high weights (AD: 0.67 and 0.38; asthma: 0.55 and 0.25, respectively). Generalized additive models showed broadly consistent single-compound associations. Estimated ecological PAFs under the 25th-percentile scenario were 7.0% for AD (G4) and 4.7% (G1), 4.0% (G2), and 6.5% (G4) for asthma.
SIGNIFICANCE: Short-term exposure to ambient VOC mixtures, particularly aromatics, is associated with an increased pediatric burden of AD and asthma in Seoul. Toluene was identified as a key contributor, whereas the roles of other VOCs require further investigation because of potential shared source contributions with other pollutants.
IMPACT: This study quantifies the short-term effects of ambient VOC mixtures on pediatric AD and asthma using advanced mixture models. The findings suggest that aromatic VOCs, particularly toluene, were consistently associated with the observed health outcomes. VOC mixture exposure may be associated with a measurable ecological burden of pediatric AD and asthma at the population level.