Heavy metals in agricultural soils and crops and their health risks in Swat District, northern Pakistan

Abstract

This study assessed the concentrations of heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni) and zinc (Zn) in agricultural soils and crops (fruits, grains and vegetable) and their possible human health risk in Swat District, northern Pakistan. Cd concentration was found higher than the limit (0.05 mg/kg) set by world health organization in 95% fruit and 100% vegetable samples. Moreover, the concentrations of Cr, Cu, Mn, Ni and Zn in the soils were shown significant correlations with those in the crops. The metal transfer factor (MTF) was found highest for Cd followed by Cr>Ni>Zn>Cu>Mn, while the health risk assessment revealed that there was no health risk for most of the heavy metals except Cd, which showed a high level of health risk index (HRI⩾10E-1) that would pose a potential health risk to the consumers.

Keywords: AAS; ANOVA; Academy of Sciences for the Developing World; Agricultural crops; BDL; CA; CAS; CRL; Cd; Centralized Resource Laboratory; Chinese Academy of Sciences; Cr; Cu; DIM; Daily intake; FAO; Food and Agriculture Organization; GIS; Geographic Information System; H(2)SO(4); HClO(4); HM; HNO(3); HRI; Health risk; Heavy metals; MTF; Mn; Ni; Nitric acid; Pakistan; Perchloric acid; RBCs; RfD; SEPA; SPSS; SRMs; State Environmental Protection Administration China; Statistical Package for the Social Sciences; Sulfuric acid; TWAS; USEPA; United States Environmental Protection Agency; WDM; WHO; World Health Organization; Zn; analysis of variance; atomic absorption spectrophotometer; average daily intake of metals; below detection limits; cadmium; chromium; cluster analysis; copper; health risk index; heavy metals; manganese; metal transfer factor; nickel; red blood cells; reference dose; standard reference materials; wet digestion method; zinc.