[HYGIENIC JUSTIFICATION OF OPTIMIZATION OF THE INTEGRATED ASSESSMENT OF DRINKING WATER ACCORDING TO THE WATER QUALITY INDEX].

The present study is devoted to theoretical questions of optimization of integrated assessment of the composition and properties of drinking water with the use of the Water Quality Index (WQI) and considering in it all 4 criteria for its hygienic quality-sanitary-toxicological, microbiological, radiation and organoleptic. There is presented a sequence of the analysis of benchmark data of the laboratory study of drinking water, including the selection of priority indices, their distribution into 4 groups according to hygienic criteria, calculations the ratios of real values (C) of indices to their hygiene MPC and the final calculation of the WQI. There is emphasized the importance of classes of hazard of substances, and the need for the special attention to the substances-carcinogens in the integrated assessment of water quality. To overcome the non-equivalence of contributions to the assessment of water quality factors, measured in different units, often disparated in their effect on human health, there are used the principles of combined action at levels below the MCL:C/MPC indices of performance of the unidirectional action are summed (e.g. carcinogenic substances), from indices of the independent action there are selected the most significant ones with the highest values of C/MPC, besides that there are also used counterbalancing factors K determined accordingly to Delphi method, with a maximum values of 5 for carcinogens and the minimum value of 1 for the substances affecting the organoleptic properties ofwater. There is presented the scheme of the final calculation of the value of WQI.

[Hygienic assessment of drinking water chlorination by-products in view of multiroute exposure].

On the example of threstationary sampling points in houses of the Western Administrative District data on presence of trihalomethanes (TGM)--the main by-products of chlorination--in cold drinking and hot tap water of Moscow were analyzed. Since 'tthe middle of 2007 the concentration of chloroform and other TGM in tests of tap water were established to be defined at levels steadily below hygienic maximum concentration limits. In the performed experiments it is revealed that, despite rather low content of chloroform in water, when using a hot shower considerable receipt of substance in air of the bathing room--in the concentration exceeding average daily maximum concentration limit in atmospheric air is possible. In calculations by the three methods of chloroform doses which can influence the person in living conditions, inhalation receipt was shown to be less if compared with an peroral way (with drinking water) and absorption through skin appear and can make the greatest contribution to the general complex loading of chloroform.