Contamination, source identification, and risk assessment of polycyclic aromatic hydrocarbons in agricultural soils around a typical coking plant in Shandong, China

ABSTRACT

Coking is one of the most important emission sources of polycyclic aromatic hydrocarbons (PAHs) in China. Investigation of the contamination, distribution, and sources of PAHs in agricultural soils around Rong Xin coking plant, China, was conducted, and the potential human health risks were addressed. The total concentration of the 16 PAHs (∑₁₆PAHs) on the United States Environmental Protection Agency priority list had a range from 1774 to 4621 µg/kg (mean 3016 µg/kg). Meanwhile, seven carcinogenic PAHs (∑PAH_7c) owned the total concentrations of 684–2105 µg/kg, and they had the benzo[a]pyrene equivalent (BaP_eq) concentrations at 139.616–1672.850 µg/kg. All soil samples were dominated by PAHs with two to four rings. Data analyses for the potential sources of PAHs showed that the PAHs in soils were principally from pyrogenic sources. Ecological risk assessment of soil PAHs showed that the BaP_eq concentrations of ∑PAH_7c accounted for 99% of the total ∑₁₆PAHs, being a major carcinogenic contributors of ∑₁₆PAHs. Higher levels of PAHs and higher total BaP_eq concentrations in this study indicate a potential carcinogenic risk for humans. Therefore, long-term exposure to coking plants may increase the PAH concentrations in the environment and further raise a potential risk to human health.

KEYWORDS:

• polycyclic aromatic hydrocarbons
• coking plant
• agricultural soil
• contamination
• risk assessment

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was supported by the “Special Fund for Agroscientific Research in the Public Interest (No. 201503107),” the National Natural Science Foundation of China (No. 21307065), and the Foundation for Outstanding Young Scientist in Shandong Province (No. BS2012HZ005).