Analysis of reference doses of chemicals introduced with drinking water

At present, many researchers highlight that the risk assessment methodology is rather static in Russian regulatory documents. This goes for both the essence of chemical exposures and reference doses stipulated for chemicals introduced into the body with drinking water. In this study, we aimed to analyze reference doses of chemicals introduced into the body with drinking water. Our research object was represented by the basic list of indicators that describe drinking water safety as per its chemical structure. Comparative analysis of reference doses of chemicals and their evidence base relied on the valid regulatory documents, Information System for Risk Assessment open-access electronic database on effects of environmental chemicals on health, and background research articles. The results obtained by assessing combined effects of chemicals on human health were generalized and visualized in MS Excel and a tool for working with graphs. The overall time period when reference doses of the analyzed chemicals were last revised was between 1987 and 2012. Not all health effects suggested in the Russian Guide on risk assessment are used as a basis for calculating reference doses of chemicals; hence, not all of them can be agreed upon on the international level at present since they do not rely on background research. Changes in reference doses occurred for chlorinated organic compounds (bromdichloromethane, tetrachloroethylene, tetrachloromethane, and trichloroethylene), lithium, cadmium, cobalt, iron, and copper. We identified certain limitations in establishing an oral reference dose of iron and ammonia, which are conventionally considered from organoleptic perception. Due to various reasons, we did not find any adequate data obtained by toxicological studies that would substantiate reference doses for copper, magnesium, ammonia, lead, silicon, bromine, and chromium under oral introduction with drinking water. We recommend considering our research data on reference doses when planning a study with its focus on impacts exerted by drinking water quality on public health and employing the risk assessment methodology to analyze oral chemical exposure.