Health risk assessment of chemical substances in drinking water in Shijiazhuang from 2014 to 2021

Abstract

BackgroundA variety of substances in drinking water are hazardous to human health and there are health risks associated with ingestion of these substances via drinking water. ObjectiveTo assess the carcinogenic and non-carcinogenic health risks of drinking water in Shijiazhuang from 2014 to 2021. MethodsThe collection, preservation, and testing of 10529 drinking water samples (including finished water and tap water) in Shijiazhuang were conducted from 2014 to 2021 and followed the Standard examination methods for drinking water (GB/T 5750—2006). The health risks of 15 chemicals in drinking water by oral exposure were assessed using the US Environmental Protection Agency's four-step method combined with Monte Carlo simulation. ResultsAmong the 15 chemicals in drinking water assessed for their health risks at general exposure levels and high exposure levels via oral route in Shijiazhuang from 2014 to 2021, the leading three chemicals and related values of carcinogenic risks for adults were cadmium (1.11×10−4, 2.98×10−4), arsenic (5.88×10−5, 1.56×10−4), and chromium (5.48×10−5, 2.41×10−4), and the leading three chemicals and related values of non-carcinogenic risks were fluoride (3.57×10−1, 6.57×10−1), arsenic (1.31×10−1, 3.47×10−1), and nitrate (1.14×10−1, 5.98×10−1). The health risk values of trichloromethane and aluminum were elevated but still in acceptable ranges. Drinking water-associated health risk values were higher in males than in females, such as the cancer risk for general exposure levels of arsenic in men was 5.76×10−5, compared to 5.72×10−5 in women. The health risk values of cadmium, chromium, fluoride, nitrate, and other chemicals in ground water were higher than those of surface water, and the health risk values of trichloromethane and carbon tetrachloride were lower than those in surface water, such as the non-carcinogenic risk value for general exposure levels of fluoride in groundwater was 3.61×10−1, compared to 2.27×10−1 in surface water. Factors such as water transmission and distribution links, water period, and season affected the health risks of drinking water. The general exposure levels of trichloromethane in tap water had a higher carcinogenic risk of 1.75×10−7 compared with 8.17×10−8 in finished water. The general levels of arsenic exposure was higher in the dry season at 1.36×10−1, compared with 1.26×10−1 in the wet season. ConclusionExcept that the carcinogenic risk of cadmium at general exposure levels in Shijiazhuang exceeds the maximum acceptable range recommended by US Environmental Protection Agency, the health risk values of the remaining 14 chemicals are below the maximum acceptable risk. The carcinogenic risk values of arsenic and chromium and the non-carcinogenic risk values of fluoride, arsenic, and nitrate are relatively high, but do not exceed the maximum acceptable ranges. The emphasis should be on the management of drinking water in highly exposed areas and populations.

Keywords

• drinking water
• health risk assessment
• carcinogenic risk
• non-carcinogenic risk
• monte carlo simulation