Pollution Status of Polycyclic Aromatic Hydrocarbons (PAHs) in Northeastern China: a Review and Metanalysis

The northeastern China is a large area with different soil types and aquatic ecosystems. In prior studies, different Polycyclic Aromatic Hydrocarbon (PAH) concentrations in soils/sediments have been reported with large spatial variabilities. Here, we reviewed the PAH concentrations in different ecosystems, and tried to identify their sources and evaluate their ecological and health risks. As a result, PAHs in most study areas ranged from 200 to 600 ng g−1 with high concentrations observed in industrial areas and low concentrations observed in mountains. Results from Monte Carlo simulation indicated that the median concentrations in coastal ecosystems, terrestrial soils and freshwater ecosystems ranged from 409.6 to 617.6 ng g−1, which suggested a weak contamination level in a large area. Source identification with Molecular Diagnostic Ratios (MDR) and Principal Component Analysis (PCA) suggested that the PAHs in all these three ecosystems were originating mainly from coal burning and vehicle emissions. In some pollution hotspots (PAHs concentrations >1000 ng g−1), the concentrations of some PAH compounds were higher than the effects range-median (ERM) quality guidelines, suggesting high ecological risks. Quantitative analysis suggested that, in coastal ecosystems and terrestrial soils, the carcinogenic risks for the three age groups were lower than 10−6, suggesting no potential for cancer development. While the carcinogenic risks for the freshwater ecosystems were higher than 10−6, indicating possible cumulative carcinogenic effects for the three age groups. This study highlighted the high ecological and carcinogenic risks in pollutions hot-spots, emphasizing that more attention must be paid to their adverse effects in the future. • Pollution status of PAHs in northeastern China were reviewed. • Terrestrial soils, coastal and freshwater sediments were weakly contaminated. • Coal combustion and vehicular emissions were the main PAH sources. • High ecological risks and carcinogenic risks were identified in pollution hotspots.