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Development of landscaping in modern cities makes it particularly important to study the properties and functions of artificial soil constructions. Carbon sequestration is one of the main ecological functions of soils, which is actively studied for the soils of natural and agroecosystems but is poorly known for urban and technogenic soils. Anthropogenic impacts are a key factor that influences the formation of carbon stocks in urban soils and, in particular, in soil constructions, characteristic of which is a high and hardly predictable heterogeneity. One of the main factors that determines the carbon pools in the soil constructions of Moscow metropolis is the volume and properties of imported soils. We have analyzed the market of soils supplied to Moscow for landscaping purposes in 2016 and 2017, the sources and volumes of imported soils and their components, their recipes, and properties using the surveys of supplier companies. Based on these data, the predicted average organic carbon stock in the upper (0–10 cm) soil layer is 84 t/ha. A comparison of our estimates and field survey data for a representative sample of Moscow soil monitoring points (n > 190) shows that the prediction gives a 1.5–2.0-fold overestimation. However, a relatively small absolute excess (by 30–40 t/ha) and similar yearly dynamics of the predicted and actual stocks (an increase by 10–14% in 2017 as compared with 2016) confirm the assumption on the decisive role of imported soils in the formation of carbon stocks in the soil constructions of Moscow and emphasize the importance of monitoring and rating of the properties of imported soils as the basis for sustainable development of urban ecosystems.

The shock interaction of a spherical rigid body with a spherical cavity is studied. This nonstationary mixed boundary-value problem with an unknown boundary is reduced to an infinite system of linear Volterra equations of the second kind and the differential equation of motion of the body. The hydrodynamic and kinematic characteristics of the process are obtained

The paper presents experience with sanitary education of workers from food industrial enterprises. The study revealed a number of disadvantages of the methodological aspect of sanitary education of these workers. A sanitary education programme has been worked out for workers engaged in food and food processing industries (production of bread, baked goods, and confectionery) and approved by the State Sanitary and Epidemiological Surveillance Department), Ministry of Health of Russia on March 1999.

Investigations of some dairy enterprises of Moscow and Moscow Province have shown that the requirements of the sanitary legislation on hygienic training of workers of these enterprises are partially fulfilled, the efficiency of training is not checked up. It is necessary to improve a training programme and the latter should be implemented only by specialists. Drawbacks in the hygienic training of dairy workers should be eliminated to provide the proper quality of dairy products.

Experience gained in the hygienic training of those who are engaged at public catering enterprises and grocery stores in different regions of the Russian Federation is presented. Hygienic training courses have been set up in the State Sanitary and Epidemiological Surveillance centers. Programs for training workers at public catering enterprises and grocery stores have been approved by the board and the Russian Federation State Sanitary and Epidemiological Surveillance Committee and the Trade Committee of the Russian Federation.

In tests on Wistar male-rats the toxic action and redistribution of the DDT repository in the fatty tissue were investigated. For this purpose a DDT depot was built up by introducing DDT in a dose of 0.2 mg/kg for a period of 6 months, following which the rats were made to fast for 20 days, this securing the egress of DDT from the depot. Furthermore, some of the rats, once the depot had been built up, were for 1 month put on a ration containing 5 per cent of protein and then subjected to fasting for 20 days, this having been done in order to study the toxic effect of DDT against the background of a diet with a low protein content. It was found that the amount of DDT retained in the organs and tissues (omentum, liver, brain) investigated in the test rats did not exceed 10 per cent of the quantity that had been introduced at the time of building up the depot. At the time of fasting there was noted migration of DDT from the fat depot, it being the same both in the test and control animals. But DDT coming from the DDT repository entered the liver and brain only in the test animals, provoking changes in the activity of a number of enzymes in these organs. A low protein diet somewhat intensified these changes.

Experimental studies on Wistar rats revealed that the fungicide calixin (N-tridecyl-2.6-dimethylmorpholine) has a teratogenic effect. This effect manifested in edemas, hemorrhages, hematomas, abnormal development of the brain (hydrocephalia), visceral cranium (micrognathia, cleft palate) and genitourinary system (hydronephrosis), in decreased size of pelvic bones, shoulder girdle, front and hind limbs, etc. Marked teratogenic effects was in good agreement with the dose. Threshold and subthreshold doses of calixin in terms of the teratogenic effect were 0.6 and 0.13 mg/kg, respectively. Calixin produces a clear-cut specific teratogenic effect that is evidenced by a wide spectrum of specific action (class I of extremely hazardous substances). The most pronounced changes were induced by calixin administration during the entire period of pregnancy (days 1-20) as compared to its administration during organogenesis (days 7-15).