Characteristics of polycyclic aromatic hydrocarbons in agricultural soils at a typical coke production base in Shanxi, China

• PAHs in arable soil of a large coke production region were investigated.
• Near 60% soil samples had the PAH level larger than 600 ng g−1.
• Soils were contaminated largely by HMW PAHs with 4–6 rings.
• The soil PAHs were from mixed petrogenic and pyrogenic sources.

There is wide concern about polycyclic aromatic hydrocarbons (PAHs) because of their carcinogenic and mutagenic potential. The coking industry is an important source of PAHs. In this study, 36 arable soil samples, a sensitive medium from the perspective of food safety and health, were collected from one of the largest coke production bases in China. The concentration of total 21 PAHs ranged from 294 to 1665 ng g−1, with a mean of 822 ± 355 ng g−1. Approximately 60% of the soil samples were heavily polluted with the level higher than 600 ng g−1. Particularly high abundances of high molecular weight PAHs were found, and the calculated BaPeq was as high as 54.3 ng g−1. Soil PAH levels were positively correlated with soil organic matter content. The soil PAHs were from complex mixture sources, and high-temperature pyrogenic sources were most likely responsible for the heavy PAH contamination. Effective control strategies and probable remediation approaches should be proposed to improve soil quality.