Ikpi George E, Nganje Therese N, Edet Aniekan, Adamu Christopher I, Eyong Godswill A
Department of Geology, University of Calabar, Calabar, Nigeria.
Department of Geoscience, University of Uyo, Uyo, Nigeria.
Geochem Trans. 2024 Sep 12;25(1):7. doi: 10.1186/s12932-024-00090-y.
Quarrying of rock aggregates generates produced water that, if not handled properly will be a source of pollution for nearby water bodies, thus affecting the chemistry of the water. This study examined the chemistry, impact of quarrying activities on water resources and the health consequences/risks posed by ingestion of the water by humans in the Akamkpa quarry region in southeastern Nigeria. Thirty (30) water samples consisting of pond water, stream water, hand dug wells, and borehole samples were collected and analyzed for their physicochemical parameters using standard methods. The results obtained from the analyses indicated that the water was moderately acidic, fresh, and not salty, with many parameters below the recommended standards with Ca, and HCO being the dominant ions present in the water resources. Rock weathering processes including silicate weathering as illustrated by hydrochemical facies, cross plots, and Gibbs diagrams are the dominant mechanisms influencing the quality and major ions chemistry of the water resources with minor contributions from dissolution, anthropogenic activities, and ion exchange. Ca-Mg-SO-Cl and Na-K-HCO are the most important water types. Although the water quality index shows that the water is suitable for human use and irrigation, the mean values of As, Cd, Pb, and Se are above the acceptable limits. Additionally, the calculated contamination factor revealed the water resources are moderate to highly contaminated by As, Cd, Cr, Mo, Pb, Sb, and Se, and are therefore unsuitable for consumption with regards to these parameters. However, the residual sodium carbonate and water hazard index (WHI) values showed that 38% to 90% of sites in the quarry area were unsuitable for cultivation, 10-30% were in the low to medium impact category, and 60% were classified as risky and are from high to very high impact category. A non-cancer study of inhabitants living in the vicinity of the quarry area indicated that 6.7% of the sites have values greater than one, indicating that it may endanger the health of the people. Therefore, constant monitoring of the water quality is recommended as long-term use of contaminated water can harm humans, plants, and soils.
岩石集料开采会产生采出水，如果处理不当，将成为附近水体的污染源，从而影响水体的化学性质。本研究考察了尼日利亚东南部阿卡姆帕采石区的化学性质、采石活动对水资源的影响以及人类摄入该地区水所带来的健康后果/风险。采集了30份水样，包括池塘水、溪水、手挖井水和钻孔水样，并采用标准方法分析了它们的理化参数。分析结果表明，这些水呈中度酸性、新鲜且不咸，许多参数低于推荐标准，钙和碳酸氢根是水资源中的主要离子。岩石风化过程，包括水化学相、交叉图和吉布斯图所示的硅酸盐风化，是影响水资源质量和主要离子化学性质的主要机制，溶解、人为活动和离子交换的贡献较小。钙-镁-硫酸根-氯离子型和钠-钾-碳酸氢根型是最重要的水型。虽然水质指数表明这些水适合人类使用和灌溉，但砷、镉、铅和硒的平均值高于可接受限值。此外，计算得出的污染因子显示，水资源受到砷、镉、铬、钼、铅、锑和硒的中度至高度污染，因此就这些参数而言不适合饮用。然而，残留碳酸钠和水危害指数（WHI）值表明，采石区内38%至90%的地点不适合耕种，10%-30%属于低至中等影响类别，60%被归类为有风险，属于高至非常高影响类别。对采石区附近居民的非癌症研究表明，6.7%的地点数值大于1，这表明可能会危害人们的健康。因此，建议持续监测水质，因为长期使用受污染的水会危害人类、植物和土壤。
