Ecological assessment of quality of drinking tap water in the content of metals

The article shows the current state regarding the problem of provision of benign drinking tap water to Zhytomyr population. It was conducted the environmental assessment of the quality of drinking water for the content of metals for a long period of time in accordance with the regulations of DSanPiN 2.2.4- 171-10 State sanitary norms and rules «Hygienic requirements for drinking water intended for human consumption» and the standards of Council Directive 98/83/EC «On the quality of water intended for human consumption». It was established that drinking tap water was characterized by low levels of contamination by cadmium, chromium, copper, molybdenum, lead, zinc, strontium and cobalt. The content of metals and elements in the water, such as beryllium, vanadium, bismuth, tungsten, lithium, arsenic, tin, silver, antimony, selenium, titanium was found in very low concentrations, and they do not cause harm to the people’s life and health. In terms of content of boron and silicon in water, the norm is not exceeded. The level of contamination of drinking water with nickel was characterized as low, iron — medium. As for the content of mercury in the water, it is necessary to conduct additional experiments as device sensitivity that we used during study was higher than the established norm and did not allow to make the conclusion about concentrations of mercury in drinking water and to assess its safety. It was established that main risk hazard for Zhytomyr population when consuming drinking water is its high toxicity associated with the high level of contamination of residual aluminium and manganese. High levels of aluminium contamination due to the use of water treatment technologies in high doses of reagents — aluminium coagulants and manganese — low quality of water at the source of drinking water, which for 2004–2017 years of observation on the average content of organic matter and manganese meet 2 — 3 class water quality according to the classification DSTU 4808:2007 «Sources of centralized drinking water supply. Hygienic and environmental requirements for quality and selection rules», and maximum content — 4 classes. In the article also shown the possible consequences of the consumption of contaminated drinking water with toxic metals for human health and proposed methods and technologies for water purification that will minimize the content of harmful, toxic elements and metals.