Source apportionment and health risk of exposure to ambient polycyclic aromatic hydrocarbons (PAHs) bound to particulate matter in Sabzevar, Iran

Abstract

Ambient polycyclic aromatic hydrocarbons (PAHs) emissions are a major environmental problem in urban areas. We aimed to assess the concentration of PAHs-bound to particulate matter (PM), source apportionment and carcinogenic risk due to inhalation exposure to PAHs. We selected 30 sampling locations in Sabzevar, Iran (2021). PM bounds-PAHs samples were collected using a PM passive sampler. Monte Carlo simulation technique with sensitivity analysis was used to assess the carcinogenic risk of inhalation exposure to PAHs. The Positive Matrix Factorization (PMF) model was used for source apportionment of ambient PAHs. The median (iterquartile range (IQR)) of total PAHs was 1056.2 (848.5) ppb. The median (IQR) ratio of total LMW/HMW PAHs was 1.9 (1.4), indicating petrogenic sources of PAHs. The 95th percentile of lifetime cancer risk (LTCR) for children, adolescents, and adults in both genders was higher than the threshold level recommended by USEPA (i.e., 1 × 10−6). The PMF model indicated five possible PAH sources, including combustion of biomass, natural gas, combustion petroleum-based fuels, traffic sources of mixed gasoline and diesel combustion, and industrial activities. The spatial autocorrelation models indicated a clustered distribution pattern for all PAHs congeners except Anthracene. Our results suggested that point sources of ambient PAHs should be paid more attention to in urban areas. Moreover, inhalation exposure to ambient PAHs had a potential carcinogenic risk for the inhabitant of Sabzevar.