[Evaluation of the efficiency of Angara River water protection measures against pollution by petroleum products].

The process installations and storage reservoirs of a petroleum refinery have leaks of petroleum products (PP) that pollute soil, underground waters, and eventually nearest water objects, by worsening their hygienic state. Environmental and economic assessments of the Angara River water protection system that is in operation at the petroleum refinery OAO "Angara Petroleum Company", which comprises well clusters, a gravel-filled trench, and a drainage system, have shown the high values of preventable relative natural and economic damages and other economic indicators. At the same time, comparison of the amount of PPs accumulated at the industrial site with their annual withdrawal has demonstrated a need for further development of a river protection system. Therefore the environmental protection system efficacy evaluated by the quality of goal attainment and by means of a matrix of algorithmized statements was 60% or 5 of 20 scores, which shows the necessity of special measures to protect Angara River waters. The elaboration and implementation of these measures associated with considerable expenditures make it possible not only to increase the environmental efficiency of water protection of the Angara River, but also to do the hygienic quality of water use in its related localities.

[Hygienic standardization of fluogermanate in the air of a working area].

The paper presents the data on the impact of the most possible concentrations of fluogermanate (GeF4) in the air of a working area with a pencil-beam irritant acting the respiratory organs and those obtained from chronic experiments. The most possible concentration is 0.2 mg/m3 (Class II hazard).

[Hygienic standardization of the levels of selenium hexafluoride in the air of a working area]. / Gigienicheskoe normirovanie geksaftorida selena v vozdukhe rabochei zony.

The paper presents the results of investigations on the hygienic standardization of the levels of selenium hexafluoride (SeF6) in the air of a working area. It also analyzes the data on the effects of SeF6 inhalation on laboratory animals, by applying morphological, physiological, hematological, and biochemical studies. The studies have yielded the basic parameters of inhalation toxicity and established the threshold of the irritant action of the substance, developed and approved its maximally acceptable concentration (0.2 mg/m3, gas + vapors) and a procedure for photometric determination of SeF6 in the air of a working area.

[Dynamics of activity of the key enzymes of polyhydroxyalkanoate metabolism in Ralstonia eutropha]. / Dinamika aktivnosti fermentov kletochnogo tsikla poligidroksialkanoatov u Ralstonia eutropha.

The dynamics of accumulation of polyhydroxybutyrate (PHB) and the activities of the key enzymes of PHB metabolism (beta-ketothiolase, acetoacetyl-CoA reductase, PHA synthase, D-hydroxybutyrate dehydrogenase, and PHA depolymerase) in the hydrogen bacterium Ralstonia eutropha B5786 were studied under various conditions of carbon nutrition and substrate availability. The highest activities of beta-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase were recorded at the stage of acceleration of PHB synthesis. The activities of enzymes catalyzing PHB depolymerization (PHB depolymerase and D-hydroxybutyrate dehydrogenase) were low, being expressed only at stimulated endogenous PHB degradation. The change of carbon source (CO2 or fructose) did not cause any marked changes in the time course of enzyme activity.