Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari, 61100, Pakistan.
Centre d'Etude et de Recherche Travail Organisation Pouvoir (CERTOP), UMR5044, Université J. Jaurès-Toulouse II, 5 allée Antonio Machado, 31058, Toulouse, France.
Environ Sci Pollut Res Int. 2020 Nov;27(32):39852-39864. doi: 10.1007/s11356-020-10106-6. Epub 2020 Jul 22.
The presence of toxic substances in aquifers, particularly potentially toxic heavy metals, is an important environmental and social concern worldwide. These heavy metals are capable to exert many injurious health effects in human beings by intake of drinking metal-contaminated water. However, very little attention is paid towards quantitative and qualitative analysis of groundwater used for drinking purpose in several less-developed countries. Therefore, this study was intended to estimate, for the first time, the heavy metal levels in groundwater/drinking water in District Vehari, Pakistan. A total of 129 groundwater samples were obtained and subjected to analyze heavy metal concentrations (lead, copper, cadmium, nickel, manganese, chromium, iron, and zinc). Moreover, pH, electrical conductivity, temperature, total dissolved solids, and anion (carbonates, chloride, and bicarbonates) and cation (calcium, potassium, sodium, lithium, and barium) contents of groundwater were also determined. It was noticed that the values of several groundwater physicochemical characteristics such as cation contents, alkalinity, chloride concentration, and especially the concentrations of heavy metals such as Pb (93%), Cd (68%), and Fe (100%) were higher than their limit values given by WHO. Principal component analysis separately grouped heavy metals and physicochemical characteristics of groundwater. The risk assessment indices predicted potential carcinogenic risks due to the consumption of metal-rich groundwater, predominantly with Cd (0.0007-0.03). The mean hazard quotient (HQ) values for all the metals were < 1, while Pb showed HQ > 1 envisaging non-carcinogenic risk with the consumption of studied groundwater. The findings of the study emphasized on the need of appropriate approaches to remediate groundwater before being used for drinking purpose.
含水层中有毒物质的存在，特别是潜在的有毒重金属，是一个全球性的重要环境和社会关注点。这些重金属通过摄入受金属污染的水，对人体健康产生许多有害影响。然而，在一些欠发达国家，很少有人关注用于饮用的地下水的定量和定性分析。因此，本研究首次旨在估计巴基斯坦Vehari 地区地下水/饮用水中的重金属水平。共采集了 129 个地下水样本，并对其重金属浓度（铅、铜、镉、镍、锰、铬、铁和锌）进行了分析。此外，还测定了地下水的 pH 值、电导率、温度、总溶解固体以及阴离子（碳酸盐、氯和碳酸氢盐）和阳离子（钙、钾、钠、锂和钡）含量。研究发现，一些地下水理化特性的数值，如阳离子含量、碱度、氯浓度，特别是重金属如 Pb（93%）、Cd（68%）和 Fe（100%）的浓度，都高于世界卫生组织规定的限值。主成分分析将重金属和地下水理化特性分别分组。风险评估指数预测了由于摄入富含金属的地下水而导致的潜在致癌风险，主要是 Cd（0.0007-0.03）。所有金属的平均危害系数（HQ）值均<1，而 Pb 的 HQ>1，表明由于饮用研究地区的地下水，存在非致癌风险。研究结果强调了在用于饮用之前，需要采取适当的方法来修复地下水。
