Personal exposure to source-specific particulate polycyclic aromatic hydrocarbons (PAHs) and systemic inflammation: the results from a cross-sectional study among the urban elderly in China

Environmental exposure to ambient polycyclic aromatic hydrocarbons (PAHs) can disturb the immune response. However, the evidence on adverse health effects caused by exposing to PAHs emitted from specific sources among different vulnerable subpopulation is limited. In this cross-sectional study, we aimed to evaluate whether exposure to source-specific PAHs could increase the level of systemic inflammation in older adults. The present study included community-dwelling older adults and collected filter samples personal exposure to PM2.5 during the winter of 2011. Blood samples were collected after the PM2.5 sample collection. We analyzed PM2.5 bound PAHs and serum inflammatory cytokines (interleukin (IL)1β, IL6, and tumor necrosis factor alpha levels. The Positive Matrix Factorization model was used to identity PAHs sources. We used a linear regression model to assess the relative effects of source-specific PM2.5 bound PAHs on the levels of measured inflammatory cytokines. After controlling for confounders, exposure to PAHs emitted from biomass burning or diesel vehicle emission was found to be associated with increased levels of serum inflammatory cytokines and systemic inflammation. In summary, exposure to PAHs from certain specific sources of PAHs may significantly enhance systemic inflammation in the elderly. These findings highlight the importance of considering exposure sources in epidemiological studies and that of controlling exposures to organic materials from specific sources.