Are the vegetables grown in the soil of municipal solid waste dumping sites safe for human health? An assessment from trace elements contamination and associated health risks

Abstract

Trace elements containing untreated municipal solid waste discharged from improper management impose serious environmental and human health risks. In this work, the extent of trace elements (As, Pb, Cd, Fe, Mn, Zn) pollution in the soils and some common vegetables/food crops grown in the municipal solid waste dumping sites in southwestern Bangladesh (Khulna) were evaluated for the first time. To assess the human consumption’s suitability of the collected vegetables cultivated in the waste dumping sites, health risks were appraised due to the trace elements contamination. The concentration of trace elements in the collected soil and vegetable/food crop samples was analyzed by Atomic Absorption Spectrophotometer. The soil pollution evaluation indices such as geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (CF), and pollution load index (PLI) were used to evaluate the soil pollution level. The results showed that trace element levels in the soils and vegetables/food crops follow the order of Fe > Zn > Pb > Mn > As > Cd. The outcome of the soil pollution indices (Igeo, EF, CF, and PLI) implies potential trace elements pollution in the dumping sites, dominated by Pb and Zn. The multivariate analyses exhibited that the trace element sources are of natural and anthropogenic origin. The estimated daily intake of the trace elements via vegetables was lower than the maximum tolerable daily intake, except for Pb. The target hazard quotients of Pb exceeded the threshold level through the consumption of all cultivated vegetables, indicating significant health risks to the residents of the study area. Hence, effective measures should immediately be taken to control the trace elements pollution due to municipal waste dumping in southwestern Bangladesh to protect the environment and human health.