Trace metal concentration in planted cucumber (Cucumis sativus L.) from contaminated soils and its associated health risks

Abstract

The concentration of trace metals (TMs) in soils and cucumber plants in contaminated and reference sites and their health risk for children and adults were investigated. Plant and soil were sampled through 30 squares distributed equally in six cucumber fields in the two sites. The pollution load index, which is the ratio of the concentration of TMs in contaminated and reference soils, showed extensive accumulation of TMs in contaminated soils. The dry and fresh biomass, and fruit production of cucumbers was significantly reduced under pollution stress. The bioaccumulation factor was > 1 for all investigated TMs, except Cd in the reference and Cd, Cr, Zn and Co in the contaminated site indicating the uptake of the investigated TMs from the soil by the root. In addition, the translocation factor to the stem and leaves was 1 for Fe in adults, and Pb and Fe in children, indicating a health risk for humans by ingestion of cucumbers, while in reference site it was 1, indicating a high potential of health hazard to consumers. It is necessary to regularly monitor toxic TMs to prevent their accumulation in the food chain.