Increased mortality risk from airborne exposure to polycyclic aromatic hydrocarbons.

ABSTRACT

BACKGROUND: The potential health effects of airborne polycyclic aromatic hydrocarbons (PAHs) among general population remained extensively unstudied. This study sought to investigate the association of short-term exposure to low-level total and 7 carcinogenic PAHs with mortality risk. METHODS: We conducted an individual-level time-stratified case-crossover study in Jiangsu province of eastern China, by investigating over 2 million death cases during 2016-2019. Daily concentrations of total PAH and its 7 carcinogenic species including benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), chrysene (Chr), dibenz[a,h]anthracene (DahA), and indeno[1,2,3-cd]pyrene (IcdP), predicted by well-validated spatiotemporal models, were assigned to death cases according to their residential addresses. We estimated mortality risk associated with short-term exposure to increase of an interquartile range (IQR) for aforementioned PAHs using conditional logistic regression. RESULTS: An IQR increase (16.9 ng/m3) in 2-day (the current and prior day) moving average of total PAH concentration was associated with risk increases of 1.90% (95% confidence interval [CI] 1.71-2.09) in all-cause mortality, 1.90% (95% CI 1.70-2.10) in nonaccidental mortality, 2.01% (95% CI 1.72-2.29) in circulatory mortality, and 2.53% (95% CI 2.03-3.02) in respiratory mortality. Risk increases of cause-specific mortality ranged between 1.42-1.90% for BaA (IQR 1.6 ng/m3), 1.94-2.53% for BaP (IQR 1.6 ng/m3), 2.45-3.16% for BbF (IQR 2.8 ng/m3), 2.80-3.65% for BkF (IQR 1.0 ng/m3), 1.36-1.77% for Chr (IQR 1.8 ng/m3), 0.77-1.24% for DahA (IQR 0.8 ng/m3), and 2.96-3.85% for IcdP (IQR 1.7 ng/m3). CONCLUSIONS: This study provided suggested evidence for heightened mortality risk in relation to short-term exposure to airborne PAHs in general population. Our findings suggest that airborne PAHs may pose a potential threat to public health, emphasizing the need of more population-based evidence to enhance the understanding of health risk under the low-dose exposure scenario.