Evaluation of human health risks by potentially toxic elements in roadside deposited sediment and road surface run-off water: A case study

To comprehend the influence of potentially toxic elements (PTEs) in the road surface run-off water (RSRW) and roadside deposited sediment (RDS) on National Highway 2 (NH-2), Delhi-Kolkata, India, 18 samples were collected transversely from 9 sampling sites. The study determined the probable cancer risk by using Monte Carlo simulation with a value (90%) of 3.2 × 10^-5 for adults and 2.7 × 10^-5 for children in RDS at the extremely polluted site. In RSRW, the study implies (90%) risk value of 1.5 × 10^-6 and 1.8 × 10^-6 for children and adults, respectively.The hazard index (HI) in RDS and RSRW was found to be 1.42 and 0.599, respectively, for children and adults at highly contaminated sites. These values were within the permissible limits (10^-6 to 10^-4). The pollution load index (P_LI) due to PTEs (Cr, Cd, Ni, Cu, Zn, and Pb) was maximum at the site S8 (3.591). This study reveals pollution load at each site along with the carcinogenic and non-carcinogenic risks in RDS and RSRW, thus perceptibly exposing the effects of contamination caused by inorganic pollutants that results in adverse health effects on residents staying in adjacent areas of the sampling sites. A similar type of study would be more useful and beneficial for identical concerns observed elsewhere in the world.