Health Risk Assessment, Composition, and Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Drinking Water of Southern Jharkhand, East India

The studies on polycyclic aromatic hydrocarbons (PAHs) occurrence, distribution, health risk, and composition in drinking water are limited in India and worldwide. The main objective of this study was to find the contaminant sources, composition, health risk, and distribution of USEPA’s 16 priority pollutant PAHs in the drinking water samples collected between July 2019 to September 2019 from six districts of Southern Jharkhand. The Σ 16PAHs mean ± standard deviation [SD] concentration values were ordered as East Singhbhum (ES) (21.5 ± 14.8 ng L −1 ) > West Singhbhum (WS) (16.57 ± 13.21 ng L −1 ) > Saraikela Kharsawan (SK) (11.48 ± 9.92 ng L −1 ) > Khunti (KH) (10.32 ± 9.09 ng L −1 ) > Simdega (SM) (9.96 ± 7.85 ng L −1 ) > Gumla (GU) (9.41 ± 8.63 ng L −1 ). The results show that ES and WS districts’ groundwater samples were more contaminated by the PAHs, which may be attributed to the presence of many small-, medium-, and large-scale industries and high vehicular density in these districts. The concentrations of lower molecular weight ring (3-rings) and middle molecular weight ring (4-rings) PAHs were dominant throughout all drinking samples. The concentration of the 3-ring PAH Anthracene and 4-ring PAH Fluoranthene were dominant in all districts. The molecular ratios suggested that the potential sources of PAHs are fuel combustion and coal, grass, and wood burning. Risk assessment shows that the incremental lifetime cancer risk and risk index (RI) were ranged from 0.02 × 10 −10 to 4.93 × 10 −10 for children and 0.01 × 10 −10 to 2.98 × 10 −10 for adults. The RI values for seven carcinogenic PAHs were 8.83 × 10 −10 for children and 7.38 × 10 −10 for adults. Although the carcinogenic risks were within the permissible values, chronic exposure to PAHs through the ingestion of drinking water could still be a human health concern.