Exploring the Effects of Air Filtration Interventions and Meteorological Conditions on Urinary Amino-PAHs as Exposure Biomarkers

A large number of air pollutants exist in a gaseous phase, some of which are considered highly carcinogenic compounds. Yet these compounds have not been as well studied as airborne particulate matter (e.g., PM10 or PM2.5). Polycyclic aromatic hydrocarbons (PAHs), especially nitrated PAHs (nitro-PAHs), are a well-known class of toxic environmental pollutants that result from industrials processes and incomplete combustion of organic fuels. This study explores meteorological and covariate effects on urinary metabolites of nitro-PAHs, namely amino-PAHs, during air pollution exposure with and without HEPA and/or ESP filtration. Urinary concentrations of cotinine (a biomarker of tobacco smoke exposure) and five specific amino-PAHs were measured including: 1-aminopyrene (1-AP), 1-naphthylamine (1-AN), 2-naphthylamine (2-AN), 2-aminofluorene (2-AF), and 2-aminophenanthrene (2-APhe). Eighty-nine subjects were assigned to one of two intervention groups in Broad Town offices located in Changsha City, China. Participants experienced periods of air pollution exposure with and without combinations of HEPA and ESP air filtration. Linear mixed effects modeling highlights the potential associations between urinary amino-PAH concentrations and covariates such as temperature and relative humidity. Additionally, both HEPA and ESP did not appear to significantly impact gas-phase levels of urinary amino-PAHs. Such findings may bring the efficacy of ESP filtration systems into question. Especially when weighing the health costs of increased ozone exposure and lack of gas-phase pollutant filtration to ESP system’s improved PM2.5 reduction. The results underscore a need for nitro-PAH related research and the potential need of gas-phase air filtration solutions that remove carcinogenic and mutagenic gas-phase air pollutants from indoor air.