Polycyclic aromatic hydrocarbons (PAHs) and their derivatives (oxygenated PAHs, azaarenes, and sulfur/oxygen-containing heterocyclic PAHs) in surface soils from a typical city, south China

Polycyclic aromatic hydrocarbons derivatives (dPAHs) were reported to be more mutagenic than parent analogues, however, studies that involving dPAHs in environmental samples are still limited. Thirty-six polycyclic aromatic compounds (PACs; 17 parent PAHs, 1 alkyl-PAH, 6 oxygenated PAHs, 6 azaarenes, 3 sulfur-containing heterocyclic PAHs, and 3 oxygen-containing heterocyclic PAHs) were analyzed in n = 100 surface soil samples collected from a prefecture-level city (hereafter referred to as D city) in South China, in the year 2019. Total concentrations of 36 PACs ranged from 3.61 to 4930 ng g(-1)with a median concentration of 86.1 ng g(-1) . Regardless of functional zones, parent PAHs were the most abundant with the proportion of 78.9%, followed by oxygenated PAHs accounting for 16.8%, whereas contents of heterocyclic PAHs were far below the formers. Besides, PAHs with 4-6 rings were the most prevalent components. Among the five functional zones, industrial zone was contaminated most severely with a mean sum PAC concentration of 485 ng g(-1), implying effects of long-term industrial emission. Total PAC concentrations in scenic and agricultural zones were significantly lower than those in industrial and residential zones. On the basis of PMF calculation, we proposed that traffic emission and biomass combustion could be responsible for PAC contamination. According to total lifetime cancer risk index, it suggested that there could be slightly health risks for children following exposure to PACs in some places.

Automated summary

The study analyzed 36 polycyclic aromatic compounds in surface soil samples collected from a prefecture-level city in South China, with parent PAHs being the most abundant, followed by oxygenated PAHs. Industrial zones showed the most severe PAC contamination, likely due to long-term industrial emissions. Traffic emissions and biomass combustion were identified as potential sources of PAC contamination, and there may be slight health risks associated with PAC exposure for children in some areas based on the total lifetime cancer risk index.