Nnorom Innocent C, Ewuzie Ugochukwu, Eze Sunday O
Environmental Chemistry Unit, Department of Pure and Industrial Chemistry, Abia State University, P.M.B 2000, Uturu, Nigeria.
Heliyon. 2019 Jan 24;5(1):e01123. doi: 10.1016/j.heliyon.2019.e01123. eCollection 2019 Jan.
This baseline study investigated the physico-chemical and trace elements (including potentially toxic elements, PTEs) contents of ground and surface water sources used for domestic purposes in some districts within the shale bedrock terrain of Southeastern Nigeria. A total of 124 water samples from 13 natural springs, 24 streams, 80 boreholes and 7 hand-dug wells were collected from rural and urban areas and analysed by ICP-OES, GF-AAS and CV-AFS for 21 elements. The distribution pattern, sources of contamination, health risk of potentially toxic elements (PTEs), together with water quality index were investigated. The results were compared with national and international guidelines for drinking water. Al and Fe were implicated as the dominant pollutants in the water bodies. Water quality index (WQI) indicated that all the water sources had either excellent or good water quality (WQ) with the exception of a borehole, which had poor WQ. Different multivariate statistical approaches applied to evaluate the origins of the elements in the water bodies identified six source types that accounted for 70.88% of the total variance. Anthropogenic activities were considered to contribute much of Cu, Pb, Cd, Cr, Li and P, while Al, As, Co, Fe, Se, Ni, Y and V were likely from crustal materials, minerals and ores, and natural environments. Both anthropogenic and natural sources accounted for the Hg, Mn and Zn. Cluster analysis (CA) was adopted to classify 124 sample points into two groups of water pollution, reflecting influences from crustal materials and anthropogenic sources. From the result of hazard quotient and index (HQ/HI), there is little or no health risks arising from PTEs in using water from the region.
这项基线研究调查了尼日利亚东南部页岩基岩地形内一些地区用于家庭用途的地下水和地表水水源的物理化学和微量元素（包括潜在有毒元素，PTEs）含量。从农村和城市地区共采集了124个水样，分别来自13个天然泉、24条溪流、80个钻孔和7口手挖井，并通过电感耦合等离子体发射光谱仪（ICP - OES）、石墨炉原子吸收光谱仪（GF - AAS）和冷蒸气原子荧光光谱仪（CV - AFS）对21种元素进行了分析。研究了潜在有毒元素（PTEs）的分布模式、污染来源、健康风险以及水质指数。将结果与国家和国际饮用水指南进行了比较。铝（Al）和铁（Fe）被认为是水体中的主要污染物。水质指数（WQI）表明，除了一个水质较差的钻孔外，所有水源的水质要么极佳要么良好。应用不同的多元统计方法来评估水体中元素的来源，确定了六种来源类型，它们占总方差的70.88%。人为活动被认为是铜（Cu）、铅（Pb）、镉（Cd）、铬（Cr）、锂（Li）和磷（P）的主要贡献者，而铝（Al）、砷（As）、钴（Co）、铁（Fe）、硒（Se）、镍（Ni）、钇（Y）和钒（V）可能来自地壳物质、矿物和矿石以及自然环境。汞（Hg）、锰（Mn）和锌（Zn）则由人为和自然来源共同造成。采用聚类分析（CA）将124个采样点分为两组水污染类型，反映了地壳物质和人为来源的影响。根据危害商和指数（HQ/HI）的结果，使用该地区的水时，PTEs对健康几乎没有风险。
