Overlooked emerging polycyclic aromatic hydrocarbons and benzofuran derivatives in soil from coking plant

Coking releases large quantities of multiple polycyclic aromatic hydrocarbons (PAHs), yet previous research has often focused on only a limited subset. This may not fully represent the overall risk posed by aromatic compounds. Here, a novel non-target analysis method was developed to identify more emerging PAHs and benzofuran derivatives. Beyond the 16 US Environmental Protection Agency priority PAHs (EPA PAHs), 56 emerging PAHs, 64 alkylated PAHs, and 32 furans were identified, with 69 compounds identified for the first time. The Σ₁₆ EPA PAHs, Σ₅₆ emerging PAHs, Σ₆₄ alkylated PAHs, and Σ₃₂ furans concentration ranges were 0.30-6910, 0.01-2187, 0.52-1649, and 0.06-588 μg/g, respectively. Emerging PAHs and furans had higher contributions in the plant area than the control area. Some PAHs and furans' concentrations were not significantly associated with the EPA PAHs; therefore, the EPA PAHs are insufficient to represent the totals PAHs concentration or risk. In the top 20 % of toxicological priority compounds, the emerging PAHs concentrations were 50 % of those of the EPA PAHs but posed 3.4 times the carcinogenic risk. Four of these compounds had higher carcinogenic risks than the EPA PAHs, while another nine had comparable risks. Thus, the risks of emerging PAHs cannot be ignored. Future monitoring and control of PAHs and furan emissions by the coking industry are highly recommended.