Evaluation of heavy metal contamination in roadside deposited sediments and road surface runoff: a case study

An exploratory study was carried out to reveal the impact of heavy metal concentration on roadside sediments and road surface runoff along the National Highway NH-2 Delhi–Kolkata, India. The study was carried out during the monsoon season to reveal the impact of heavy metal concentration on the roadside along the National Highway NH-2 Delhi–Kolkata, India. This study presents the heavy metal concentration observed on the deposited sediment and surface runoff. Eighteen sediment and surface runoff samples were collected during the monsoon from nine different locations and were analyzed for the residual concentration using atomic absorption spectroscopy. The experimental results showed that the concentrations of heavy metals were very high for the following sampling points: ADDA more at Asansol (S8) and Ranisayer at Raniganj (S9). To calculate analytical results, and to detect the possible pollution sources of heavy metal correlation analysis and for principal component analysis, agglomeration schedule of cluster analysis was applied to the data matrix. The geo-accumulation index (Igeo) and enrichment factor analysis revealed the major sources of contamination, viz. lithology, traffic volume, and industry and road construction. The present study is essential in the regional aspect where the heavy metal pollution provokes and causes health issues to the residents. This study could also be beneficial to similar scenario seen elsewhere in the world.