Evaluation of factors influencing the trace metals in Puducherry and Diu coasts of India through multivariate techniques

Highlights: • The highest contamination factor was observed for Cd in sediment at Diu. • Risk index was considerable at Diu and low at Puducherry. • Iron (3016–38,219 ppm) showed highest variation in sediments of the Diu coast. • Cadmium (0.2–0.75 ppm) showed least variation in sediments of the Puducherry. In recent years, urban and industrial development initiatives at Puducherry and Diu such as tourism, shipping, and fisheries have led to sediment contamination by trace metals, and contributed to this investigation that extended from 2016 to 2017. Strong factor loadings of Cd (0.94), Ni (0.84), Al (0.84), Cr (0.83), Co (0.82), and Fe (0.78) illustrated the variability at Puducherry, whereas Cr (0.88), Cd (0.86), Ni (0.83), Co (0.77), Cu (0.77), and Fe (0.77) showed variability at Diu. The mean rank order distribution of the top three metals in sediment was Fe > Al > Mn, which exhibited higher variability. The highest contamination factor was observed for Cd at Diu, whereas the lowest was observed at Puducherry for Al. Similarly, the risk index also exhibited considerable risk which could be attributed to Cd contamination in the sediment at Diu compared with that at Puducherry. The results obtained are essential to establish a reference for better comparison and management of the tropical environments.