Polycyclic aromatic hydrocarbons (PAHs) in multi-phases from the drinking water source area of the Pearl River Delta (PRD) in South China: Distribution, source apportionment, and risk assessment.

Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were investigated in the water dissolved phase (DP), suspended particulate matter (SPM), and sediment collected from the water source zone of the Pearl River Delta region. The sum of 16 PAH concentrations ranged from 92.8 to 324 ng/L in the water DP, from 28.8 to 205 ng/L in the SPM, and from 55.7 to 381 ng/g (d.w.) in the sediment. Compared with other areas globally, the PAH levels were considerably moderate in the DP and SPM and relatively low in the sediment. Spatial distribution of PAHs was site-specific, and relatively higher PAH levels were found in the areas with dense population and heavy traffic. The PAH profile was dominated by two- and three-ring PAHs, and PAH pollution was identified of pyrolytic origins. Based on risk quotient, the ecological risk in water was ranked as moderate, but the adverse health risk associated with water ingestion was minimal. Naphthalene and fluorene of the sediment samples showed potential biological impairment in some locations; nevertheless, the mean effects range median quotient suggested that the ecological risk of multiple PAHs was quite low (less than 10% incidence of adverse effects).