Search

In many countries, where wastewater irrigation has become a common practice, the accumulation of heavy metals by crops has been regarded as a severe environmental hazard. The evaluation of the toxic element lead (Pb) in water, agricultural soils and food crops, and their potential damage to human health, is the focus of the present study. Samples of eleven food crops, soil, with three treatments, waste, canal, and tube well waters, were collected from three feeding sites, Sargodha city, Sahiwal, Shahpur, and evaluated for Pb concentration. The results indicates that the range of Pb in the water, soil and crop samples were from 0.023 to 0.039 mg/L, 2.932–13.687 mg/kg and 1.241–4.825 mg/kg, respectively. The metal concentration was significantly higher (P < 0.001) in wastewater treated soil and crop samples that exceed the permissible limit of the World Health Organization (WHO). There is a positive correlation between the Pb concentration in the soil and crop samples. The pollution load index and enrichment factor are greater than 1, indicating a high level of soil contamination and the influence of natural and anthropogenic sources of Pb metal accumulation in soils. The bioconcentration factor (BCF), daily intake of metal (DIM), health risk index (HRI) and metal values are less than 1, indicating that toxic Pb are present in lower quantities in food crops and had no health risks to consumers. In wastewater treated soils, there is a significant accumulation of Pb toxicity. Therefore, it is vitally important to address Pb contamination and its potential entrance route into the human food chain. • This study collected 27 water and 99 soil and food crop samples from 3 sites in Sargodha. • The relationships of lead (Pb) contents in irrigated water soil and crops were explored. • The pollution load index and enrichment factor were greater than 1, indicating a high level of soil contamination. • Pb toxicity accumulated in wastewater treated soils. [ABSTRACT FROM AUTHOR]

Accumulation of toxic heavy metals (THMs) in the soil-water-plant can negatively affects regional eco-safety and poses a threat to agricultural productivity, ecosystem, animals, humans and plants. Additionally, THMs can enter human bodies through the food chain, leading to an increased incidence of chronic diseases such as deformity and cancer. Leafy vegetables irrigated with untreated as well as contaminated waters were usually abounded with heavy metals in high concentrations. These contaminated leafy green vegetables although very popular here, may cause threats to human health, since these are usually grown in sub-urban areas, by irrigations of the untreated contaminated waters (canal water, groundwater and waste water carrying many city effluents). In this study, we analysed and measured the levels of hazardous metals (Zn, Cr, Ni, Cd, Cu, Fe and Pb) found in spinach (Spinacia oleracea L.) at 3 different places of district Sargodha. Results revealed that the measured concentrations of Cd in water and spinach, and that of Pb in spinach were exceeding the standard permissible limits. High values of health quotient were found for Cr, Cd and Pb. The sequence of EC was recorded in ascending order as Pb > Cr > Cd > Ni > Zn > Cu >Fe in all the samples which were examined. The results of the study conclude, as the heavy metals are carcinogenic for human health, not only proper monitoring of soil and irrigation water should be made as well as such contaminated vegetables may be avoided. • Non-conventional water resources (NCW) are alternate option for agriculture, landscaping, and forestry. • Ground water, canal water and city effluents wastewater were evaluated for trace metals (HMs) impact on spinach. • Cd and Pb was higher in spinach after treatment with three wastewater. • High values of health quotient were found for Cr, Cd and Pb. • Water treatment technologies should be advocated and implemented for safe use of NCW. [ABSTRACT FROM AUTHOR]