Levels, profiles and potential human health risks of brominated and parent polycyclic aromatic hydrocarbons in soils around three different types of industrial areas in China

Brominated polycyclic aromatic hydrocarbons (Br-PAHs) are an emerging class of persistent organic pollutants with toxicity similar to dioxins. Industrial thermal processes have been identified as major sources of Br-PAHs in the current environment. However, studies on soil contaminations with Br-PAHs around industrial areas were scarce. In this study, 18 Br-PAHs and 16 PAHs were analyzed in soils around an electronic waste dismantling area (EDA), an industrial area that mainly performed steel smelting (SSP), and an industrial area mainly performed secondary copper smelting (SCS). The mean concentrations of Br-PAHs and PAHs were 1362 pg/g and 1034 ng/g, 582 pg/g and 13,938 ng/g, and 307 pg/g and 2211 ng/g in the soil around EDA, SSP, and SCS, respectively. The order of Br-PAH concentrations among three industrial areas was inconsistent with that of PAHs, suggesting that there may be some differences in contamination characteristics of Br-PAHs in three types of industrial areas. The significant correlation between Br-PAHs and parent PAHs indicated that direct bromination may be the main formation pathway of Br-PAHs in soils in EDA. The result of principal component analysis further revealed that the congener pattern of Br-PAHs in soils around EDA is different from that of SSP and SCS. It was found that the ratio of 1-BrPyr and 3-BrFlu can be applied to identify environmental contamination with Br-PAHs from e-waste dismantling. The health risk assessment results showed that there were some soil samples with carcinogenic risks above the risk threshold in each industrial area, and deserve our concern.