Interdisciplinary Research Center for Membrane and Water Security, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.
Department of Geology, Chukwuemeka Odumegwu Ojukwu University, Uli, Nigeria.
Chemosphere. 2023 Sep;336:139083. doi: 10.1016/j.chemosphere.2023.139083. Epub 2023 Jun 16.
Fluoride and nitrate contamination of groundwater is a major environmental issue in the world's arid and semiarid regions. This issue is severe in both developed and developing countries. This study aimed at assessing the concentration levels, contamination mechanisms, toxicity, and human health risks of NO and F in the groundwater within the coastal aquifers of the eastern part of Saudi Arabia using a standard integrated approach. Most of the tested physicochemical properties of the groundwater exceeded their standard limits. The water quality index and synthetic pollution index evaluated the suitability of the groundwater and showed that all the samples have poor and unsuitable quality for drinking. The toxicity of F was estimated to be higher than NO. Also, the health risk assessment revealed higher risks due to F than NO. Younger populations had higher risks than elderly populations. For both F and NO, the order of health risk was Infants > Children > Adults. Most of the samples posed medium to high chronic risks due to F and NO ingestion. However, negligible health risks were obtained for potential dermal absorption of NO. Na-Cl and Ca-Mg-Cl water types predominate in the area. Pearson's correlation analysis, principal component analysis, regression models, and graphical plots were used to determine the possible sources of the water contaminants and their enrichment mechanisms. Geogenic and geochemical processes had greater impact he groundwater chemistry than anthropogenic activities. For the first time, these findings provide public knowledge on the overall water quality of the coastal aquifers and could help the inhabitants, water management authorities, and researchers to identify the groundwater sources that are most desirable for consumption and the human populations that are vulnerable to non-carcinogenic health risks.
地下水的氟化物和硝酸盐污染是世界干旱和半干旱地区的一个主要环境问题。这个问题在发达国家和发展中国家都很严重。本研究旨在采用标准综合方法评估沙特阿拉伯东部沿海含水层地下水中的 NO 和 F 的浓度水平、污染机制、毒性和对人类健康的风险。大多数测试的地下水理化性质都超过了标准限值。水质指数和综合污染指数评估了地下水的适宜性，结果表明所有样本的水质均较差，不适宜饮用。氟化物的毒性被评估为高于硝酸盐。此外，健康风险评估显示，氟化物比硝酸盐的风险更高。年轻人群比老年人群面临更高的风险。对于 F 和 NO，健康风险的顺序是婴儿>儿童>成人。由于摄入 F 和 NO，大多数样本都存在中等到高的慢性风险。然而，由于潜在的皮肤吸收，NO 的健康风险可以忽略不计。该地区以 Na-Cl 和 Ca-Mg-Cl 水型为主。皮尔逊相关分析、主成分分析、回归模型和图形图用于确定水污染物的可能来源及其富集机制。地球化学和地球化学过程对地下水化学的影响大于人为活动。首次发现这些结果提供了关于沿海含水层整体水质的公共知识，可帮助居民、水管理当局和研究人员确定最适合消费的地下水水源和易受非致癌健康风险影响的人群。
