Hygienic assessment of population health risk under exposure to chemicals that penetrate drinking water from household water mixers

Abstract

At present a truly vital task is to evaluate possible changes in the structure and properties of drinking water occurring in the process of delivering it to end customers. Our research aim was to perform hygienic assessment of health risks caused by consumption of drinking water with changed chemical structure influenced by domestic faucets made from zinc alloys. Hygienic assessment of drinking water was performed to test its conformity with the requirements fixed in the Sanitary Rules and Standards SanPiN 1.2.3685-21 “Hygienic standards and requirements to providing safety and (or) harmlessness of environmental factors for people”. Water samples were aged in new household water mixers with their cases made from ZAM zinc alloy (a zinc alloy doped with aluminum, magnesium, and copper) at pH6 and pH9 in accordance with the State Standard GOST 34771-2021 “Sanitary-technical water mixing and distributing accessories. Testing procedures”. Health risks for children and adults and population risks were assessed for situations involving oral and cutaneous introduction according to the Guide R 2.1.10.1920-04 Human Health Risk Assessment from Environmental Chemicals. We established that water samples aged in household water mixers contained authentically elevated concentrations of metals included into ZAM alloy, namely copper, nickel, lead, and zinc, both at pH = 6 and pH = 9. We also detected enhanced organoleptic properties: color grew by 2–2.3 times and turbidity by 2.3–5 times. Carcinogenic risks caused by consuming water with changed properties turned out to be unacceptable both for children and adults. We also established that calculated hazard index for the blood system didn’t conform to hygienic requirements; calculated hazard indices for the central nervous system, liver, hormonal and reproductive systems were statistically significantly higher when people consumed drinking water with changed properties. We also calculated population carcinogenic risks for the whole population in the Russian Federation based on the maximum possible exposure to drinking water with changes in its chemical properties due to household water mixers. The total population risks amounted to approximately 131 thousand cases. Our research indicates it is necessary to develop preven-tion activities with a carefully planned monitoring system and control over quality and use of domestic faucets.