Health Risk Assessment of Inhalation Exposure to Airborne Particle-Bound Nitrated Polycyclic Aromatic Hydrocarbons in Urban and Suburban Areas of South China.

Airborne particulates (PM2.5 and TSP) were collected from outdoor and indoor areas at urban (Haizhu District) and suburban (Huadu District) sites from 2019 to 2020 in Guangzhou. Three nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in the airborne particulates were identified by a gas chromatograph equipped with a triple-quadrupole mass spectrometer. In the Haizhu District and Huadu District, the nitro-PAH concentrations in PM2.5 and TSP did not show a significant decrease from winter to summer. From 2019 to 2020, the difference in the average concentration of nitro-PAHs in PM2.5 and TSP in Guangzhou was relatively low and had no statistical significance. The diagnostic ratios of 2-nitrofluorene (2-NF)/1-nitropyrene (1-NP) in TSP are less than five, while for 2-NF/1-NP in outdoor PM2.5 in the summer of 2019 and 2020 are more than five, which indicates that nitro-PAHs in the atmospheric PM2.5 in Guangzhou during summer mainly originated from the secondary formation of atmospheric photochemical reactions between parent PAHs and oxidants (·OH, NO3, and O3). 9-Nitroanthracene (9-NT) made the most significant contribution to the total nitro-PAH concentration. The incremental lifetime cancer risks (ILCRs) of nitro-PAHs in PM2.5 and TSP by inhalation exposure indicated low potential health risks in the urban-suburban of Guangzhou.

Distribution, source, and health risk assessment of polycyclic aromatic hydrocarbons in the soils from a typical petroleum refinery area in south China.

The ubiquity of polycyclic aromatic hydrocarbons (PAHs) in soils in petroleum refining areas is an important problem affecting human and ecological safety. In this study, 103 topsoil (0-0.50 m) samples were collected from a retired petroleum refinery area in Guangdong province, south China. The PAHs concentrations were determined by ultrasonic extraction and gas chromatography-mass spectrometry detection methods. Twelve PAHs controlled priority listed by the US Environmental Protection Agency (USEPA) were investigated. The results revealed that the concentration of Æ©12PAHs ranged from 2100 to 5200 µg kg-1, with a mean value of 3741.66 µg kg-1. The site was dominated by high rings PAHs (4-, 5-, and 6-ring), contributing 81.96% to Æ©12PAHs. The concentrations of 9 kinds of PAHs exceeded the Dutch soil quality standard. Besides, the PAHs were primarily distributed in the storage tank area and with high levels of contamination. The results of hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicated that coal combustion was the source of PAHs in topsoil, followed by petroleum dripping and traffic emissions. The incremental lifetime cancer risk (ILCR) modeling illustrated that soil ingestion was the major pathway of PAH exposure for both adults and children. Notably, the total noncarcinogenic human health risk due to PAHs was within the limit of 1, while the carcinogenic risks alone caused by benzo(a)pyrene via soil ingestion to adults and children were obviously beyond the USEPA limit (1.00E -06). Therefore, PAHs in the petroleum refinery areas have potential carcinogenic hazards to human health, the area should be remediated before reuse.