Source Apportionment and Source-specific Toxicological Risk Assessment of PAHs in a Typical Industrial Site in Ningxia.

Large-scale industrial activities are one of the main sources of environmental pollutants. The pollution problems of industrial sites and their surroundings are more typical and prominent than those of other environments. In order to explore the pollution level, composition, source and toxicological risk of polycyclic aromatic hydrocarbons (PAHs) in the soil of a typical industrial park in Ningxia, this study collected 108 surface soil samples from enterprises and the surroundings belonged to metallurgy, chemical pesticide manufacturing, chemical manufacturing, etc. The concentrations of 16 PAHs were analyzed by gas chromatography-mass spectrometry (GC-MS). Positive matrix factorization (PMF) was used for source apportionment. Toxic equivalent concentration (TEQ), mutagenic equivalent concentration (MEQ), and incremental lifetime carcinogenic risk (ILCR) were used for toxicological risk assessment. Then, the source-specific carcinogenic and mutagenic risk contributions are further assessed to facilitate risk-based management and control of emission sources. The results showed that the average concentration of PAHs in the surface soil of the industrial park was (2 029.1 ±5 585.9) μg·kg-1, which was at a relatively high pollution level in China and in Ningxia. The main sources of PAHs were traffic sources (53.9% ), heavy oil combustion (27.0% ), and the combustion of coal and biomass (14.9% ) and steel industry (4.2% ). The main polluting industries in the park are the manufacture of activated carbon, lime nitrogen and metallurgy. The ILCR of adults was 4.510-6, and the potential carcinogenic risk mainly came from ingestion and dermal exposure. Traffic sources contributed the largest carcinogenic risk (45.4% ) and mutagenic risk (43.4% ). [ABSTRACT FROM AUTHOR]