Determination of Heavy Metals and Health Risk Assessment in Tap Water from Wuhan, China, a City with Multiple Drinking Water Sources

Abstract

The health issues of urban tap water are of great concern in the context of sustainability challenges to the environmental quality of water and the security of the water supply. In this work, tap water from the main urban areas in Wuhan and surface water from the Yangtze River and the Hanjiang River were collected during summer (June) and winter (December), 2022. The concentrations of 10 heavy metals including Fe, Al, Mn, Co, Ni, Cu, Se, Cd, Cr and Pb were determined for water quality evaluation and health risk assessment. The results demonstrated that almost all of the tap water samples contained metal concentrations below the Chinese national standard limits for drinking water (GB 5749-2022). The risk of heavy metals in tap water to human health was evaluated, and the results showed that the total carcinogenic risk (TCR) was in the range of 10−6 and 10−4 and the hazard index (HI) was much lower than one in both summer and winter. The current tap water in Wuhan is generally in a relatively safe state and will not cause acute hazards or chronic diseases in the short term, but the long-term cancer risk is still noteworthy. The heavy metal pollution index (HPI) showed that the overall water quality of urban drinking water sources in Wuhan has been satisfactory, despite its slightly polluted state in winter. Pipeline corrosion was considered as one of the important sources of heavy metals in Wuhan tap water, which can explain, to a certain extent, the increase in the heavy metal concentrations of tap water outlets relative to the finished water reported by waterworks, such as Fe, Ni, Cd and Pb. This study has implications for the formulation of better urban water supply security management strategies and associated sustainability challenges.