Assessment of Groundwater Quality and Nitrate Related Risks to Human Health: A Case of Angads Plain, Morocco

Abstract

This study aims to assess groundwater quality and the human health risks associated with nitrate contamination using a human health risk assessment model. 45 groundwater samples were collected in 2016 and 2023 in the Angads aquifer. According to the findings, the groundwater was brackish (TDS > 1000 mg/L), extremely hard (TH > 450 mg/L CaCO₃), and contained ions in the sequence Na⁺  > Ca²⁺  > Mg²⁺  > K⁺  > NH₄⁺ for cations, and Cl⁻ > HCO₃⁻ > SO₄²⁻ > NO₃⁻ for anions. The TH-TDS graph and the groundwater quality index (GWQI) show that the majority of samples are unfit for consumption. Based on NO₃⁻ concentrations most often observed in the south of the research area, where many activities are likely to be sources of nitrates, the human health risk assessment reveals high non-carcinogenic risks for people living in the region, particularly for infants (71.1% on 2016 and 93.3% on 2023). Consumption of groundwater contaminated with nitrates over a long period could present a potential risk to human health.