Tracking the trace element pollution and associated health risk in urban coastal groundwater, eastern Saudi Arabia

Groundwater is a critical source of freshwater for community use in the eastern region of Saudi Arabia. However, it faces a quality decline due to rapid urbanization and intensive agricultural activities. The current study aims to investigate the occurrence and distribution of trace and toxic elements in the groundwater and assess their potential impacts on human health and ecological life. Groundwater samples were collected from 35 wells along the eastern coast and analyzed for 17 traces and toxic elements. Multiple indices were implemented to assess the pollution level, water quality, and associated ecological and human health risks. The results of the water quality index (WQI) and pollution index (PI) reveal that 35.3% and 22.9%, respectively, of tested samples are unsuitable for human consumption. The ecological risk analysis(PERI) indicates that 52.9% of water samples pose low risk, while 23.5%, 14.7%, and 8.8% display low, moderate, considerable, and high risk, respectively. The study also found that arsenic poses a high carcinogenic risk in 77% of water samples, while chromium exhibits a high risk in only 17%. Moreover, arsenic and chromium are the primary sources of elevated non-carcinogenic risk, particularly for children (71.4%). The spatial distribution analysis reveals that the central part of the study area exhibited elevated levels of element pollution and the associated human and ecological risk. The integration of demographic data with pollution and risk spatial analysis helped to identify the hotspot zones that require prioritized mitigation and monitoring. The study demonstrates the need for ongoing environmental monitoring of the trace and toxic elements in the groundwater to safeguard public and ecological health and ensure sustainable groundwater usage.