Refined Risk Assessment of Typical Polycyclic Aromatic Hydrocarbons in a Coking Site.

In order to address the excessive stringency of the remediation target values derived from human health risk assessments based on total concentrations of PAHs, the bioaccessibility of benzo [b] fluoranthene (BBF), benzo [k] fluoranthene (BKF), benzo [a] pyrene (BAP), indeno[1,2,3-cd]pyrene (IPY) and dibenzo [a,h] anthracene (DBA) in the soils of a coking plant in Shijiazhuang, were tested using the German Standards Institute (Deutsches Institut für Normung, DIN) method. The results showed that: (1) the concentrations of BBF, BAP, IPY and DBA in the soils of the investigated area exceeded the screening values of the first type of land-use in GB36600--2018; (2) the bioaccessibility of the five PAHs in the soils of the coking plant ranged from 14.71% to 56.42%; (3) the health risks of BBF, BKF, BAP, IPY and DBA were reduced after taking into account the bioaccessibility, of which the risk of BBF was reduced to an acceptable level; (4) the target values (95% UCL) of BAP, IPY and DBA increased by 2.6, 3.4 and 1.5 times with taking bioaccessibility into account, which were 2.83, 34.63 and 1.95 mg⋅kg^-1, respectively. Carrying out refined health risk assessments of PAHs in the soils of coking sites can resolve the problems of overly stringent remediation targets resulted from the conservative risk assessment in the current technical guidelines. [ABSTRACT FROM AUTHOR]