Exposure to Fine Particulate Matter and Inflammatory Cytokines and DNA Methylation in Healthy Young Adults

Abstract

Background/Aim: Protective benefits of indoor air filtration in areas with high pollution levels are not fully understood. This study aims to examine whether short-term air filtration intervention could attenuate the hazards from acute exposure to fine particulate matter (PM2.5), and investigate the potential impact of this exposure on inflammatory cytokines and DNA methylation. Methods: A randomized, double-blind crossover trial of true or sham indoor air filtration was conducted among 29 healthy young adults in Beijing, China. Each episode covered a typical air pollution smog event, and 38 cytokines and their corresponding DNA methylation in the study participants were measured at three time points: pre-smog, during smog, and post-smog. Indoor PM2.5 concentrations were measured using an aerosol spectrometer and outdoor PM2.5 concentrations were collected from fixed-site monitoring stations. Linear mixed-effect models were used to evaluate the associations between exposure and outcome variables. Results: The indoor PM2.5 concentration with true filtration was 67.8% lower than sham filtration (13.8 μg/m3 vs. 42.8 μg/m3). Air filtration was significantly associated with decreases of 6.61% to 35.46% in 13 cytokines. Time-weighted personal PM2.5 exposure was significantly associated with changes in 11 cytokines and methylation at 27 CpGs. Specifically, PM2.5 exposure was associated with increases in MCP-1, MCP-3 and sCD40L, but hypomethylation in corresponding genes. Conclusions: This trial suggests that indoor air filtration might attenuate the adverse effects of PM2.5 exposure through changing cytokines and DNA methylation.