Groundwater from the Mocorito River aquifer in Mexico has been historically employed for both human consumption and irrigation of its overlaying agriculture fields. The aim of this research was to investigate the levels and distribution of potentially toxic elements (PTEs) in the aquifer to determine their sources and to assess their potential health risks. Groundwater samples were collected from wells at eighteen sites in two climatic seasons. In the dry season, mean dissolved concentrations (µg L⁻¹) of As, Pb, Cd, and Cr were 3.19, 0.05, 0.02, and 0.15, respectively, and their total (unfiltered) concentrations were 4.10, 0.47, 0.05, and 0.52, respectively. While in the rainy season, their dissolved concentrations were 4.60, 0.03, 0.01, and 0.06, respectively, and their total concentrations were 5.58, 0.25, 0.01, and 0.12, respectively. On average, concentrations of the four PTEs were below national and international guidelines for drinking water. Concentrations of As exceeded the WHO (2007) guidelines (10 µg L⁻¹) at three sites and had yielded relatively high values of both chronic daily intake and hazard quotient. Lifetime cancer risk for As indicated the probability for developing this disease of 1 in 10, 000 inhabitants. Pearson’s correlation and principal component analysis (PCA-Varimax) were carried out. According to these, all the PTE concentrations were mainly derived from natural lithogenic sources. Arsenic concentrations constitute potential human health concerns for both direct consumption and its bioaccumulation in local crops. Finally, due to high As concentrations in some sites in the aquifer, the implementation of a sustainable groundwater management plan in the MORCA, that include a monitoring of PTE levels, is recommended.

墨西哥莫科里托河含水层的地下水历来被用于人类消费和灌溉其覆盖的农田。本研究的目的是调查含水层中潜在有毒元素 (PTE) 的水平和分布，以确定其来源并评估其潜在的健康风险。在两个气候季节从 18 个地点的井中收集地下水样品。在旱季，平均溶解浓度 (µg L ⁻¹) 的 As、Pb、Cd 和 Cr 分别为 3.19、0.05、0.02 和 0.15，它们的总（未过滤）浓度分别为 4.10、0.47、0.05 和 0.52。而在雨季，它们的溶解浓度分别为4.60、0.03、0.01和0.06，总浓度分别为5.58、0.25、0.01和0.12。平均而言，四种 PTE 的浓度低于国家和国际饮用水准则。As 浓度超过 WHO（2007）指南（10 µg L ^-1) 在三个地点，并且在慢性每日摄入量和危害商数方面都产生了相对较高的值。终生癌症风险 正如所指出的，每 10,000 名居民中就有 1 人患上这种疾病。进行了皮尔逊相关性和主成分分析（PCA-Varimax）。据此，所有 PTE 浓度主要来自天然岩源。砷浓度对直接消费及其在当地作物中的生物积累构成潜在的人类健康问题。最后，由于含水层中某些地点的砷浓度较高，建议在 MORCA 实施可持续的地下水管理计划，其中包括监测 PTE 水平。