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This study is devoted to the investigation of possibility to use the total organic carbon as regulated index in drinking water as well as to the issues of hygienic regulation and harmonizing this index with the standards of other countries. Basing on the results of 3 years lasting investigation carried out by Municipal Unitary Enterprise "Vodokanal" of Yekaterinburg city permits to propose as the most informative and reliable index of the presence of organic substances in drinking water the content of total organic carbon in comparison with currently regulated permanganate oxidability, chemical and biochemical oxygen consumption.

Cytogenetic assay of the chromosomal apparatus of human blood lymphocytes was carried out after in vitro irradiation by heavy charged particles with high LET values. Blood plasm samples enriched with lymphocytes were irradiated by accelerated ions of carbon 12C (290 MeV/nucleon and LET = 70 keV/microm), neon 20Ne (400 MeV/nucleon and LET = 70 keV/microm), and iron 56Fe (500 MeV/nucleon and LET = 200 keV/microm) in the dose range from 0.25 to 1 Gy. Rate of chromosome aberrations showed a linear dependence on doses from the densely ionizing radiations with high LET values. Frequency of dicentrics and centric rings in human lymphocytes irradiated by 12C with the energy of 290 MeV/nucleon was maximal at 1 Gy (p < 0.05) relative to the other heavy particles. It was found that relative biological effectiveness of heavy nuclei is several times higher than of 60Co gamma-radiation throughout the range of doses in this investigation.

The article covers results of clinical and roentgenologic data analysis. The data were obtained in the study that covered 447 pneumoconiosis patients, 75 of which were subjected to high resolution CT. If compared to chest X-ray, high resolution CT helps more precise forecast of further course in pneumoconiosis.

The case-study results reveal a co-carcinogenic ability of carbonaceous dusts and cokes used in productions involving pitch and pitch-containing substances. Maximum permissible concentration (MPC) of 6 mg/m3 as approved by GN 2.2.5.686-98 for carbon dust (coal-, sand-, pitch-, oil- and shale cokes) was adopted only on the basis of data characterizing its fibrogenic activity and without respect to its co-carcinogenic action. There is a lack of hygienic norms for carcinogenic pitch dusts in the Russian hygienic legislation. Our research denote convincingly the need in a hygienic standardization of pitch and (polycyclic-aromatic-hydrocarbons)-containing carbonaceous dusts with due respect to their carcinogenic activity, whose indicator could be the quantity of benzapilene (BP) contained in them. On the basis of the results the below MPCs can be suggested: coal pitch with BP of up to 15000.0 mg/kg-0.01 mg/m3; oil pitch with BP equal to or below 1500.0 mg/kg-0.1 mg/m3; BP-containing carbon dusts--equal to or below 150.0-1.0 mg/m3, which is in line with the MPC approved in the Russian Federation for BP--0.15 micron/m3. The introduction of the above hygienic norms is needed to ensure an effective sanitary monitoring for the purpose of preventing an occupation carcinogenic hazard in productions with pitch and pitch-containing carbonaceous substances.

Due to the high level aggressiveness of asbestos, more attempts have been made in the recent years to replace asbestos by other artificial mineral fibres. In this connection, the labour conditions were studied in the basalt and carbon fibres processing sites. The major occupational hazards of these sites included basalt and carbon fibres dusts, heating microclimate in some working zones and physical overload. An intratracheal experiment revealed a lower degree of fibrinogenicity of the basalt and carbon fibres as compared to chrysotile asbestos. The number of the induced mesothelioma in the intraperitoneal introduction of basalt and carbon fibres was markedly lower than in case with chrysotile asbestos. Hygienically, asbestos should be replaced wherever possible, and the dust control measures should by no means be inferior to those with asbestos.

Carcinogenic hazards for workers of certain plants of steel, asbestos, oil-producing, oil-refining and chemical industries were studied. Potential carcinogenic hazards for workers of graphite industry conditioned mainly by coke and graphite dust adsorbed polycyclic hydrocarbons, particularly, benzo(a)pyrene made the case for cancer epidemiologic studies which were carried out at some of those plants in the 70s. Exposure to polycyclic hydrocarbons adsorbed on industrial dust was shown to significantly increase the incidence of lung cancer.

As a result of retrospective studies on cancer mortality among workers engaged in the carbon black industry, it was found that the mortality rate from cancer of the lung, stomach and gastrointestinal tract within this cohort of workers is higher compared with the population of the surrounding district and distant to it.

As a result of complex hygienic, clinical and cancer epidemiologic studies, dust proved to be a major occupational hazard. Coke and graphite dust absorbs polycyclic aromatic hydrocarbons, including benz(a)pyrene in concentrations exceeding maximum permitted levels. Screening of 746 graphite workers followed by clinical examination established increased incidence of diseases of the upper respiratory tract (chronic rhinitis pharyngitis, laryngitis, etc.), bronchi and lungs (chronic bronchitis or pneumonia) and skin (hyperkeratosis, naevi, etc.). Among respiratory diseases were hypertrophic laryngitis, papillomatous bronchitis and angiofibroma of the larynx which are now considered to be precancer. Cancer epidemiologic studies referred graphite workers to a group of high risk of cancer.

Structural lesions in neurons of the brain cortex of rats were investigated 1 and 3 months after their exposure to accelerated carbon ions with the energy 320 MeV/nuclon 10(4) particles/cm2 (LET = 120 MeVcm2/g) as well as to gamma-radiation in the dose 1.0 Gy. The irradiated animals showed morphofunctional, dystrophic and reparative lesions in neurons. The rats exposed to carbon ions developed more distinct changes that the animals exposed to gamma-radiation. It is postulated that similar fluxes of cosmic radiations will not produce a deleterious effect on the integrative functions of the central nervous system of cosmonauts.