[Effect of long-term exposure to carbon disulfide on various biochemical indices in albino rats]. / Vliianie na produlzhitelna serovuglerodna ekspozitsiia vurkhu niakoi biokhimichni pokazateli v organi na beli plukhove.

The effect of carbon sulphide was studied on sexually matured male and female albino rats, subjected to 180-day exposure with concentrations 0.03, 50 and 200 mg/m3, 6 hours daily, 5 days a week. Carbon sulphide effect was studied by indices, characterizing the state of the oxidation processes and lipid metabolism. CS2--50 and 200 mg/m3 were established to inhibit oxygen consumption of liver homogenates, better manifested in female animals, whereas in homogenates of testicles the tissue respiration was significantly inhibited only with 200 mg/m3. Some sexual discrepancies were observed in the indices of lipid metabolism, significantly changed with a concentration of 200 mg/m3. More susceptible, in male animals, proved to be the level of free fatty acids and total cholesterin, whereas in females--liver phospholipids, in all cases lower than the control group.

[Hygienic evaluation of the planning and construction of housing complexes]. / Khigiena otsenka na planiraneto i stroitelstvoto na zhilishtni kompleksi.

Three blocks of flats were the subject of this study. They have been projected and built at different periods and the study covers the following principal aspects: sanitary urbanization analysis, assay of some of the basic environmental physical factors and physiologic reactions of the human organism and atmosphere contamination. These blocks of flats are still unable to provide wholy adequate sanitary conditions, in conformity with the urbanization setup, edifice situating, planning and organization of public services on the territory and anthropogenic factors. For an optimal environment one should take into consideration all sanitary requirements early in the process of projecting blocks of flats.

[Hygienic effect of landscaping in urban areas]. / Kum khigienniia efekt na ozeleniavaneto v gradskite zoni.

The atmospheric environment in two blocks of flats with different degree of gardens and parks lain out and in a town park in Sofia was studied by the basic physical, chemical and physiologic parameters. The results give grounds to admit that laying out gardens and parks in urban zones contributes to the creation of definite, qualitatively and quantitatively different housing environment: a more favourable temperature-and-moisture, radiation - thermal and biologicaly active regime. The physiologic state of residents, looking for recreation in these places, was better in an environment of ample verdure. Laying out gardens and parks should gain wider acceptance in the urbanization of bloks of flats, since it is an effective means of improving the hygienic merits of housing environment.

[Carcinogenic action of diarsenic trioxide]. / Vurkhu kantserogennoto deistvie na dvuarsenoviia triokis.

Biarsenic trioxide under the experimental conditions outlined in the paper causes mainly adenopapillomatous proliferations in the intestine and partly in the stomach, as well as adenomatous proliferations in the lungs, all of which may be considered as precancerous conditions. Having in mind that no cancerigenic actions of arsenic has been proved hitherto, the experimental data submitted assume a particular theoretical and practical interest.

[Effect of meteorological factors on the 3,4-benzpyrene concentrations in the ground air layer in the region of the city of Sofia]. / Izsledvane vliianieto na meteorologichnite faktori vurkhu kontsentratsiite na 3,4-benzpiren v prizemniia vuzdushen sloi v raiona na gr. Sofiia.

An investigation is performed to determine 3,4-benzpyrene content in the Sofia area (in a single spot), covering a one-year period (1970), on the basis of mean monthly concentrations established through gas chromatography, and compared to some of the averaged meteorologic data. The correlation between 3,4-benzpyrene concentrations and some meteorologic factors found is corroborated by the clearcut seasonal fluctuations of 3,4-benzpyrene concentrations in the atmospheric air. An inversely proportional dependence is established of 3,4-benzpyrene concentration to the summed up radiation, and directly proportional--to the dust amount. A rise of 3,4-benzpyrene concentration under conditions of the various types of temperature inversions, and a complex effect of meteorologic factors have been also noted. Moreover, an attempt is made at establishing the washing effect of rainfalls, and it has been found that up to a certain extent, such an effect really exists. The study performed shows in a clearcut manner that 3,4-benzpyrene content is considerably influenced by a variety of meteorologic factors.