[The importance of sanitary microbiological indices in the evaluation of epidemiological safety of water use in conditions of chemical contamination of water].

The increasing chemicalization of production and life leads to the pollution of water bodies by chemicals, the effect of which on the micro - and macro - organisms is poorly understood. This section of the study in sanitary bacteriology is becoming ever more topical and is an important task of modern hygienic science. One of complicacies of the study of the problem is related with the fact that the presence of only experimental data fails to be sufficient, as the impact of any given chemical substance on different bacteria in the experiment does not mean that under natural conditions, similar results will be obtained. One reason for this may be the inhibitory effect of the given chemical on biological properties of bacteria, while in field conditions in the water several chemicals interacting with each other can exist. In this regard, the aim of the work was to assess the indicator value of sanitary and microbiological indices of epidemic hazard of water use in conditions of chemical pollution of surface water bodies.

[Determination of ammonia in ambient air by ion chromatography].

The use of the well-known methods for testing the content of ammonia in the air of a populated area at the average daily maximum allowable concentration (0.04 mg/m3) is associated with the high requirement for chemical reagents and with considerable time. Deionized water proposed to be used as an absorption solution in the sample collector with the final ion chromatographic determination of ammonia is an alternative to solving the problem and enables air ammonia to be determined with a sensitivity of 0.02 mg/dm3.

[Problems in the monitoring of bromine-containing substances in the drinking water].

The water concentrations of bromide ions at the level of 0.2 mg/dm3 or higher, which are sufficient for redox reaction of humin compounds under the action of potent oxidizing agents present a potential hazard in the hygienic terms of formation of transformation products, which also agrees with the hygienic standards. The concentration of bromide ions below 0.1 mg/dm3 can be considered to be relatively safe in the terms of production of organobromine compounds.

[Hygienic assessment of a recirculatory combined air-conditioning extract-and-input system in office building].

The high concentrations of lead were reveled in the air and dust of some premises and on the filters of a combined air-conditioning extract-and-input system in the high-rise office buildings located in the ecologically lead favorable environment. The dust content of lead in some premises on the first floors dust was as high as 200 mg/kg, which was more than 6 times higher than that in the soil at the highway near the office buildings. The use of new technologies and devices for cleaning and optimizing the air in the premises requires analytical studies to assess the quality of the environment, by taking into account the optimal conditions of their operation.

[Electrochemical purification of natural waters from humic compounds].

The article presents a comparative analysis of chemical substances which are formed in natural waters with different concentrations of humic and fulvic acids under the influence of ozone and chlorine, as a result of electrochemical processing. The authors present thermodynamic evaluation of the probability of the formation of transformation products under the influence of oxidizing reagents and during anode oxidation, and demonstrate the effectiveness of electrochemical purification of natural waters from humic compounds by cathode activated carbon. The scheme of a device to perform this process has been developed.