[The results of studies of the effect of asbestos on the health of working people and the population, conducted by the Yekaterinburg Medical Research Center].

The paper presents the basic results of 75-year studies of the Yekaterinburg Medical Research Center to evaluate the effect of asbestos on the health status of working people and the population, which have yielded basic hygienic, sanitary, clinical, epidemiological, and experimental data on the effect of asbestos on the health status of working people and the population and led to the conclusion that the center's experience in studying the problems may serve as the real basis for substantiating the safe permissible controlled use of chrysotile asbestos.

[Sanitary characteristics of the production of asbestos membranes]. / Gigienicheskaia kharakteristika proizvodstva asbestovykh membran.

The paper presents preliminary results of sanitary assessment of the production of asbestos membranes. The production may emit highly disperse asbestos-containing aerosols of disintegration with low levels of filamentous particles and respirable fibers of chrysotile-asbestos into the air of working areas. It is concluded that latest chrysotile-asbestos processing is not a significant source of air pollution in the working areas where asbestos-containing and related noxious substances are present.

Retrospective view of airborne dust levels in workplace of a chrysotile mine in Ural, Russia.

The Bazhenovskoye chrysotile asbestos deposit has been exploited for 115 years. All the technological operations in the quarry are accompanied by the formation of high-dispersion asbestos-containing aerosols. The dust concentrations at the miner's working places for the last 30 years (1970-2000) were at or below the Russian MACs(m.s.) level (4.0 mg/m3). The seasonal precipitation amount in the deposit area causes a rise in dust content in certain periods. The maximum density of asbestos respirable fibres exceeded 2.7 f/cm3. All the identified fibres belonged to chrysotile asbestos, and no amphibole asbestos, such as tremolite asbestos, has been identified. An excessive dust level remains, despite the dust content level decrease, at the work sites of oversized lump drillers and unloaders, and oncopathology heightened risk remains in these occupational groups, as a result.

[Asbestos: contemporary problems of industrial medicine and ecology]. / Asbest -- sovremennye problemy meditsiny truda i ékologii.

The article covers main steps of research work conducted by Ekaterinbourg Medical Research Center and determines contemporary problems of asbestos. The authors list priority directions of ecologic and hygienic research on the "Asbestos and Health" problem.

[Occupational problems of serpentine asbestos in industry (history and trends)]. / Gigienicheskie problemy khrizotil-asbesta v promyshlennosti (istoriia i perspektivy).

The article presents summarized data of long-standing research of work conditions, asbestosis occurrence, and epidemiology of malignancies in "URALASBEST" enterprises extracting and utilizing asbestos. The research served as a base to elaborate and put into practice a complex of sanitary, technical, medical and biologic measures in various asbestos enterprises. Those measures lowered occupational morbidity due to asbestos. Considering the experience accumulated, the authors set prospects for further studies on "Asbestos and Health" problem.

[Occupational health issues at enterprises and utilization of road-building materials derived from the wastes of lead-containing enriched ore from the Aktovrak mines]. / Gigienicheskaia kharakteristika proizvodstva i primeneniia materialov dlia dorozhnogo stroitel'stva iz otkhodov obogashcheniia asbestovykh rud Aktovrakskogo mestorozhdeniia.

The article presents results of hygienic research assessing use of asbestos materials in road building. Asbestos materials used are waste products of asbestos ore enrichment at Aktovraksky layer (Tuva Republic). The main hazard was proved to be a highly dispersed asbestos-containing aerosol of complex composition, with low content of fiber particles (0.8-1.4%) and respirable fibers (0.25-6%) particularly. The calculated concentrations of asbestos fibers did not exceed the MAC adopted in most countries (1 fiber/ml). Airborne levels of asbestos in road building and exploitation are within the national standard.

[The danger of developing lung cancer in the manufacture of asbestos panel]. / Opasnost' razvitiia raka legkikh v proizvodstve asbestovogo kartona.

The article presents results of study covering mortality with lung cancer among the staffers of 2 enterprises producing asbestos cardboard. The study proved that long work in dusty conditions (dust concentration nearly 1.0 mg/m3) does not result to higher risk of death with lung cancer. However the influence of increased concentrations of dust requires further investigations.

Solubility of chrysotile asbestos and basalt fibers in relation to their fibrogenic and carcinogenic action.

Fiber length and persistence are thought to be determinants for the development of toxic, fibrogenic, and carcinogenic effects of fibrous dusts. When the solubilities of chrysotile asbestos (CA) and basalt fibers (BF) were compared by measuring the loss of silica and magnesium in Leineweber's solution, CA was shown to be the more soluble. In a 6-month inhalation experiment, chrysotile at a mean concentration of 25 mg/m3 had a higher clearance rate than other comparable dusts. In acute toxicity studies, chrysotile and basalt fibers were administered intraperitoneally. At a dose of 1.7 g/kg body weight of CA, one third of the animals died. A dose of 2.7 g/kg body weight killed all the animals. With BF, even at a dose of 10 g/kg body weight all the animals survived. When the two fibers were administered over a 6-month period, either intratracheally or by inhalation, fibrotic lesions were more common in the group that received CA. Intraperitoneal administration of CA led to three times as many deaths from peritoneal mesothelioma as administration of BF. It appears, therefore, that in spite of its higher solubility and lower persistence, CA was the more toxic, fibrogenic and carcinogenic fiber, which gives rise to the hypothesis that the surface chemistry of the fibers is the determinant for biological activity.

[Comparative evaluation of fibrogenesis and toxicity of asbestos-containing heat-proof materials]. / Sravnitelnaia otsenka fibrogennosti i tiksichnosti asbestsoderzhashchikh teploizoliatsionnykh materialov.

The article deals with the results of studies analyzing the fibrogenic activity and toxicity of asbestos-containing heat insulators exemplified by asbestos board, vulcanite and asbestos vermiculite. Physical and chemical parameters of the studied dust are presented. All studied dust types have the distinct fibrogenic activity, the highest one was seen in asbestos board. The studied dust types could be classified according to the acute toxicity: asbestos board (DL50-3.2 +/- 0.09 g/kg), chrysotile asbestos (DL50-2.0 +/- 0.08 g/kg), vulcanite (DL50-1.9 +/- 0.08 g/kg) and asbestos vermiculite (DL50-0.7 +/- 0.04 g/kg). The article touches upon the probable acting mechanism of acute toxicity of asbestos and asbestos-containing dust.

[Comparative evaluation of dust oncogenicity in asbestos-containing and non-asbestos details]. / Sravnitelnaia otsenka onkogennosti pylei asbestoformovannykh detalei na bezasbestovoi i asbestovoi osnove.

Experiments proved higher carcinogenicity of chrisotyle-asbestos than of dust appearing in mechanical processing of asbestos-containing details and in wearing articulated shoe brakes. Substitution of asbestos for basalt fibers leaves oncologic risk intact among workers engaged into mechanical processing of asbestos-containing brakes. Avoiding asbestos in mixtures for brakes could lower risk. Results support conclusions obtained by cohort studies in Yaroslavl.

[Effect of low concentration of asbestos-containing dust]. / K voprosu o deistvii nizkikh kontsentratsii asbestosoderzhashchikh pylei.

Dust, particularly fibrous, in atmosphere of Asbest town was characterized. Pulmonary cancer mortality in Asbest town and towns of nearby area were compared and no significant difference was found. Overall pulmonary cancer mortality was higher in the region than in Asbest. Obtained data served as a basis for discussion on the action threshold of asbestos-containing dust. MAC for asbestos fibers in atmosphere is reported to be 0.06 respirable fibers per ml.