Polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments of Suzhou Industrial Park, an emerging eco-industrial park in China: Occurrence, sources and potential risk

In this study, urban stream sediment samples were collected in the Suzhou Industrial Park (SIP), one of the earliest national demonstration eco-industrial parks of China. PAHs were analyzed in these sediments, and concentrations of total PAHs were 180?81,000 ng g-1 (5700 ? 14,000 ng g-1). Medium molecular weight (4ring) PAHs were predominant (42 ? 12%), followed by high molecular weight (5- and 6- ring) PAHs (31 ? 10%). No correlation was found between concentrations of PAHs and land uses of SIP in this study. Diagnostic ratios and a positive matrix factorization (PMF) model indicated that coal/biomass combustion might be the primary PAH source (61%), followed by non-combustion sources (21%) and vehicular emission (18%). According to the spatial analysis, PAHs in the sediments of SIP might be mainly associated with the coal/biomass combustion in the northeast industrial zone. Residential & commercial activities seem not to be the major causes of PAH contamination. Total PAH toxic equivalent concentrations, effect range low/effect range median values, and mean effects range?median quotient all showed that PAHs were present at a low toxicity risk level in most regions of the SIP. However, vigilance is required at some sampling sites with extremely high PAH concentrations or high mean effects range?median quotient.

Automated summary

PAHs were the main pollutants in sediment samples from Suzhou Industrial Park, likely originating primarily from coal/biomass combustion, rather than residential and commercial activities. While most regions showed low toxicity risk levels for PAHs, vigilance is required at sampling sites with extremely high concentrations or high mean effects range?median quotient.