Sources apportionment and carcinogenic risk of polycyclic aromatic hydrocarbons in gas phase of urban Shanghai: Based on high volume solid phase extraction (Hi-volume SPE)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, posing potentially serious threats to human health. This study analyzed compositional characteristics, sources, and carcinogenic risks of PAHs in the atmospheric gas phase at an urban site in Shanghai, East China. Seventy-four gas phase samples were collected during the warm months of May–October 2018 using a high-volume solid phase extraction (Hi-volume SPE) technique. The total concentration of sixteen priority PAHs (ΣPAHs) was in the range of 5.54–182.05 ng m−3 (average 34.47 ng m−3) and the total of seven carcinogenic PAHs (ΣCPAHs) was in range of 0.03–1.49 ng m−3 (average 0.48 ng m−3), accounting for 1.47% of ΣPAHs and indicating low carcinogenic potential. Redundancy analyses indicated positive correlations between ΣPAHs and air quality, and ΣCPAHs and average high temperature, and a negative correlation between ΣPAHs and wind speed. Four possible sources, namely petroleum and petrogenic sources, traffic emissions, coal combustion, and mixed gasoline and coal combustion sources, were identified by positive matrix factorization (PMF), accounting for 62.84%, 19.31%, 10.15%, and 7.69% of ΣPAHs, respectively. The overall lifetime lung cancer risk (LLCR) through inhalation of PAHs was estimated to be at a low risk level of 1.61 × 10−5. The LLCR based on PMF apportionment decreased in the order of mixed gasoline and coal combustion sources (47.07%) > traffic emissions (35.10%) > petroleum and petrogenic sources (11.06%) > coal combustion (6.74%). This study demonstrates the effectiveness of Hi-volume SPE in collecting and analyzing atmospheric gas phase PAHs.