College of Environmental Science and Engineering, Guilin University of Technology, #12 Jiangan Road, Guilin City, Guangxi, 541004, People's Republic of China.
School of Environmental Studies, Department of Environmental Science, China University of Geosciences, Wuhan, China.
Environ Sci Pollut Res Int. 2019 Oct;26(30):30642-30662. doi: 10.1007/s11356-018-2320-8. Epub 2018 Jun 18.
Arsenic (As) contamination in drinking water is a global public health risk. The present study highlighted the geological and anthropogenic causes of As contamination in groundwater (GW) and surface water (SW) and assessment of their potential health risks in Sindh province of Pakistan. Upon analyzing 720 GW and SW samples from 18 different sites, the estimates of As in groundwater and surface water was observed in the range of 0 to 125 and 0 to 35 μg/L with mean values of 46.8 and 15.43 μg/L respectively. Majority of the samples exceeded WHO permissible limit of As (10 μg/L) with higher concentration detected in groundwater samples compared to surface water. Moreover, both of these sample sources were found not potable based on physicochemical characteristics. The results of statistical analysis (correlation analysis, principal component analysis (PCA), and hierarchy cluster analysis (HCA)) indicate that natural mobilization of As in groundwater is believed to be enhanced by the pH-based reductive dissolution of iron hydroxide (FeOH) and competitive sorption of bicarbonate minerals in the presence of microorganisms along with evaporative enrichment while water logging, coal mining, and excessive use of pesticides are believed to be the anthropogenic causes of As enrichment. Furthermore, enormous health risk was associated with As in terms of chronic daily intake (CRI), hazard quotient (HQ), and cancer risk probability (CR) in GW and SW. Mean HQ values in GW were 4.47 mg/kg/day in adults and 3.89 mg/kg/day in children (standard HQ ≤ 1) and was 1.43 and 1.28 mg/kg/day in SW. Mean CR value in both GW and SW was found higher than the safe limit (10) having a mean of 2 × 10 in GW and 7 × 10 (mg/kg/day) in SW. These findings suggest that majority of the sampling sites carry serious public health risk due to high As values and hence demands exigent remedial and management measures.
砷（As）污染是全球公共卫生的一大风险。本研究重点分析了巴基斯坦信德省地下水（GW）和地表水（SW）中砷污染的地质和人为成因，并评估了其潜在健康风险。在对来自 18 个不同地点的 720 个 GW 和 SW 样本进行分析后，发现地下水和地表水的砷含量范围分别为 0 至 125μg/L 和 0 至 35μg/L，平均值分别为 46.8μg/L 和 15.43μg/L。大多数样本都超过了世界卫生组织规定的砷限值（10μg/L），地下水样本的浓度高于地表水样本。此外，根据理化特性，这两种水源都不适合饮用。统计分析（相关性分析、主成分分析（PCA）和层次聚类分析（HCA））的结果表明，在微生物存在的情况下，pH 值引起的铁氢氧化物（FeOH）还原溶解以及碳酸氢盐矿物的竞争吸附会增强地下水砷的自然迁移，同时还存在蒸发浓缩富集现象；而水涝、采煤和过度使用农药则被认为是砷富集的人为成因。此外，GW 和 SW 中的砷还会导致慢性每日摄入量（CRI）、危害系数（HQ）和癌症风险概率（CR）等方面存在巨大的健康风险。GW 中成人的平均 HQ 值为 4.47mg/kg/天，儿童为 3.89mg/kg/天（标准 HQ≤1），SW 中的 HQ 值分别为 1.43mg/kg/天和 1.28mg/kg/天。GW 和 SW 中的平均 CR 值均高于安全限值（10），分别为 2×10 和 7×10（mg/kg/天）。这些发现表明，由于高砷值的存在，大多数采样点都存在严重的公共健康风险，因此需要采取紧急补救和管理措施。
