Accumulation and distribution of heavy metals in soil and food crops around the ship breaking area in southern Bangladesh and associated health risk assessment

Abstract

Heavy metal pollution in agricultural soils and food crops around the ship breaking area is of great environmental and human health concern. In this work, we have spectroscopically determined the concentrations of Cd, Pb, Fe, Mn, Zn, Cr, Cu, and Ni in agricultural soils and commonly consumed vegetables, fruits, and rice grain collected from the Sitakunda ship breaking area of Chittagong, Bangladesh, in order to evaluate their contamination levels and probable human health risk with a multivariate statistical approach. Multivariate analyses such as principal component analysis and cluster analysis of the analytical data indicate a significant metal contamination in the samples which could be attributed to industrial activities such as ship breaking. The results of soil contamination evaluation indices such as enrichment factor, geo-accumulation index, and contamination factor demonstrated that the soils around the ship breaking area are mainly contaminated by Cd, Pb, Zn, and Cu while food crops were mostly contaminated by Zn, Cr, and Cu. The Pb contaminated the olive and teasle gourd while Cd contamination in rice grain was at the threshold limit for health hazard. Mn was slightly accumulated in banana. Transfer coefficient values of Cd, Zn, and Cu for almost all food crops were higher than other metals, and Cd showed the highest transfer. Estimated daily intake values for Ni exceeded the standard limit (1.3 μg kg−1 day−1). Target hazard quotient values of Cu, Zn, Pb, and Cd indicate that the local inhabitants who consume the contaminated food crops are being exposed to potential health risks.