Essential elements and standards for their contents in drinking water

Certain essential and conditionally essential natural elements (selenium, chromium, iodine, molybdenum, cobalt, vanadium, fluorine, lithium, silicon, boron, and bromine) are standardized in terms of their contents in drinking water as per sanitary-toxicological parameters of adverse health effects. Our research goal was to determine a contribution made by drinking water into supplying a human body with essential natural elements as well as to substantiate the necessity to update standards regarding these substances. We applied calculation models for dose equivalents of essential elements MPC (maximum permissible concentration), MPC calculations for these substances basing on a necessary 20 % contribution made by drinking water into reference doses, and calculation of non-carcinogenic health risks due to essential elements occurrence in specific drinking water sources with these elements being distributed into different groups as per similar effects produced on certain organs and systems in a body. We took existing drinking water sources containing 6 essential elements with similar effects as an example and applied a procedure for assessing non-carcinogenic health risks. Acting nickel and selenium MPC do not supply a body with an optimal daily intake whereas their determined MPC are not only harmless but also conform to the minimum necessary intake dose. At the same time neither acting lithium MPC nor its calculated one taking into account risk assessment based on internationally accepted reference doses doesn’t provide the minimum necessary daily intake into a human body. When boron and vanadium are contained in drinking water in a concentration close to their MPC, then their 20 % contribution into the reference dose is exceeded (71.4 % and 164.7 % accordingly). Introduction of these essential elements with food can become a factor that determines non-carcinogenic risk level.