[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.

[Hygienic problems of hot water supply for the population].

The paper reviews the literature on the current hygienic problems of centralized hot water supply for the population. It gives data on the types of domestic hot water used by the population in quantities and at temperatures. The paper considers the importance of meeting the standards for the temperature of hot water at the points of water pumping to prevent legionellosis and other diseases associated with the opportunistic microflora being in hot water. The possible negative effect of chlorinated water disinfection byproducts, present in hot water on the population's health is considered in detail.

[Hygienic assessment of the characteristics of centralized hot water supply in case of Moscow].

The paper considers the characteristics of domestic hot water consumption by Moscow dwellers. It gives the results of questionnaire surveys in 100 respondents aged 20-80 years about the modes and intensity of hot water use, by indicating the time and frequency of contact with hot water complaints about hot water supply. According to the authors'studies, the daily consumption of hot water per capita was 1.1-2 times greater than that of cold water; at the same time the total water use remained to be 1.3-3 times less than the Moscow standard levels. Top stationary point measurements of water temperature showed the noncompliance with its hygienic requirements: 95 of 98 hot water samples had a temperature of 5-22 degrees C less than the standard temperature (60 degrees C). A decrease in hot water temperature in the centralized hot water supply systems creates conditions for Legionella pneumophila propagation and ensures no hot water safety with regards to the possible development of Legionella pneumonia.

[Topical aspects of hot water supply to the population].

The aspects of hot water supply, which determine the safety of hot water delivered to the population, are considered. The authors underline the antiepidemic value of hot water temperature maintenance at the water pumping points of not below 60 degrees C as only this measure liably prevents water multiplication of Legionella pneumophila that induces legionellosis, a severe disease, as well as other high temperature-resistant microorganisms. The results of estimating the residential use of hot water, according to which the hot water script is diverse and accounts for as many as 17 different operations made by women and, in some cases, taken an average of 1.5 hours to the maximum of up to 4 hours a day, are given. There is a need for mandatory monitoring for the level of chloroform in the chlorine-decontaminated water supplied to the population.