Heavy Metal Contamination of Irrigation Water, Soil, and Vegetables and the Difference between Dry and Wet Seasons Near a Multi-Industry Zone in Bangladesh

Abstract

Heavy metal (Cr, Cu, Zn, As, Cd, and Pb) contamination in irrigation water, soil, and vegetables was investigated in farmland adjacent to a multi-industry zone in Bangladesh in dry and wet seasons. In the zone, many factories release wastewater into nearby irrigation canals, and vegetables cultivated with this water could be a major food chain route for human exposure. In the irrigation water and vegetables, heavy metal concentrations exceeded permissible levels in the two seasons, but this was not the case in soil. Zn had the highest concentration, and Cd had the lowest concentration in irrigation water, soil, and vegetables. All heavy metal concentrations were found to be lower in the wet than in the dry season, which is due to the dilution of water by rainfall, lower absorption of heavy metals from the diluted irrigation water, and heavy metal absorption from low concentrated irrigation water and/or soil. The cluster analysis data of irrigation water, soil, and vegetables revealed that the heavy metals in vegetables were considered to be absorbed from irrigation water in the wet season and from soil in the dry season. In the dry season, the high heavy metal concentrations in vegetables might be caused by a high bioconcentration factor (mostly > 20%).

Accumulation of heavy metals and bacteriological indicators in spinach irrigated with further treated secondary wastewater

“…BCF >1 indicate that the heavy metals are easily taken up by plants from the soil through the plants organs and these organs accumulate these heavy metals and BCF <1 indicate that spinach absorbed these heavy metals but did not store them ( Chopra and Pathak, 2012 ). It has been reported that BCF ratio >0.20 indicates high contamination of vegetables by human activities hence high risk to health ( Ahmed et al., 2019 ). The BCF ratios of the heavy metals during the first month were >0.2 but the spinach was not ready for harvest during the time hence low public health risk.…”

Potentially Harmful Element Concentrations in the Vegetables Cultivated on Arable Soils, with Human Health-Risk Implications

“…On the other hand, contamination of the food chain, leading to potential health risks, is one of the major environmental pathways of human exposure to potentially harmful elements (PHEs) [3]. Thus, more and more studies have been conducted on the contamination of edible plants with PHEs and the related health-risk implications [3,4,5,6,7,8,9,10].…”

Magnetic Nitrogen-Doped Porous Carbon Nanocomposite for Pb(II) Adsorption from Aqueous Solution

“…Human activities and development depend essentially on water [ 1 , 2 ]. Water pollution and associated problems are increased with the rapid progress of urbanization, industrialization, and the direct release of various contaminants such as heavy metals into clean water sources [ 3 , 4 ]. The hard degradation of heavy metals, their persistence, toxicity, and mobility in water sources have made these ions the most dangerous of all contaminants.…”