Carcinogenic and endocrine-disrupting PAHs in the aquatic ecosystem of India.

The quantification studies of 17 carcinogenic and endocrine-disrupting polycyclic aromatic hydrocarbons (PAHs) in the Mithi River polluting the Mahim Creek near Mumbai were performed to understand their sources and probable ecological risk. The overall concentration level of ΣPAHs was 157.96 ± 18.99 μg L, while that of carcinogenic PAHs (ΣC-PAHs) was 81.31 ± 9.75 μg L, which corresponds to 51.5 % of the ΣPAHs. The source analysis of PAH pollution was made on the basis of different PAH ratios. It was observed that the probable PAH contamination was due to pyrogenic inputs arising due to the combustion of grass, wood, and coal as well as due to the combustion of diesel and gasoline. Toxicity and biological risk assessment was made using toxic equivalent quantity (TEQ) for various C-PAHs. The results of our study showed that the mean BaP concentration in the Mithi River water (8.61 μg L) was above the European Directive 2008/105/EC Environmental Quality Standards (EQS) value of 0.05 μg L, while the levels of benzo(k)fluoranthene (BkF) + benzo(b)fluoranthene (BbF) (21.54 μg L) and benzo(g,h,i)perylene (BghiP) + indeno(1,2,3,-c,d) pyrene (InP) (18.27 μg L) were significantly higher than that set by the EQS (0.03 and 0.002 μg L, respectively), showing that the ecological integrity of the river and the adjoining creek is possibly at risk.