Lower Respiratory Tract and Home Dust Microbiomes and Traffic Pollution Exposure. Lung and Home Dust Microbiomes

Exposures to both biological aerosols and traffic-related air pollution have well-documented adverse health effects. These exposures are relevant to public, environmental, and occupational health. The goal of this study was to further our understanding of biological aerosol and traffic pollution exposure by providing new insight into the impacts of traffic pollution on the body. The two main objectives of the study were to 1) examine the effect of traffic pollution exposure on the respiratory microbiome, and 2) to characterize and compare the microbial communities of the respiratory tract and home dust, which is representative of the bioaerosol exposure in the home.In Aim 1, we collected induced sputum samples from a longitudinal cohort of adolescents with a well-characterized traffic pollution exposure history. Metagenomics sequencing, specifically 16s rDNA for bacteria and ITS rDNA for fungi, was used to compare the microbial communities in the sputum of the adolescents in the high and low traffic pollution exposure groups. In Aim 2, the sputum and saliva samples collected for Aim 1 were characterized along with home dust samples taken from the same participants. The bacterial and fungal diversity and community compositions of each sample type were compared. Quantitative polymerase chain reaction was used to quantify the total bacterial and fungal load in each sample type. We also examined the differences in the microbial communities of home dust between traffic pollution exposure groups, genders, and asthma status. The results of Aim 1 showed that there is an association of traffic pollution exposure and bacterial diversity in the lower respiratory tract. Aim 2 showed that the bacterial and fungal communities in sputum, saliva, and dust differed, but that there were no observable differences in the home dust communities between the high and low traffic pollution exposure groups. The results of this study suggest that bioaerosols and traffic pollution should be examined together in future exposure assessment research.