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Extremely high toxicity of metal-containing nanoparticles necessitates search of methods to increase body resistance against its harmful effects. The authors' experiments summarized in the article demonstrated that some combinations of certain biologically active substances selected according to sound theoretic background and prescribed in harmless doses can significantly decrease integral and specific manifestations of organ and system toxicity and even genotoxicity of such nanoparticles. Further development of this research direction should be recommended for practical implementation.

Judging by the cytological characteristics of the free cell population of the lower airways obtained with assistance of the bronchoalveolar lavage in 24 hours after the intratracheal instillation of equal doses of equidimensional gold or silver nanoparticles, both metals result in active recruitment of phagocytes with domination of neutrophile leukocytes, especially marked after the instillation of the nanosilver. The higher ratio of these cells count to that of alveolar macrophages gives evidence for the significantly higher cytotoxicity of the nanosilver comparing with both nanogold and even the smallest silver particles in the micrometric range. Transmission electron microscopy demonstrates similar pictures of intracellular distribution and ultra-structural damages caused by internalized nanoparticles in both types of phagocytes, while there are significant differences between cells under impact of nanosilver vs. those under impact of nanogold. The highest importance is higher propensity of the nanosilver particles to aggregation and to ingression into mitochondria with damaging these organelles.

The authors compared cytotoxicity of magnetite (Fe3O4) particles in nanometric ranges (10 nm and 50 nm) and micrometer range (1 microm), analyzing changes in cellular subunits of bronchoalveolar lavage in 24 hours after intratracheal application of the particles. Findings are that the nanoparticles are more biologically aggressive than the micrometric particles, but induce more active and effective defensive reaction of alveolar fagocytosis.

The authors consider the organization of a system for monitoring of ambient air pollution by suspended matter (by fractions of less than 10 microm and less than 2.5 microm) as one of the most urgent tasks in the harmonization of the Russian and western methods for assessing the quality of the environment. The frame plan for organization of ambient air suspended matter monitoring in the countries of Eastern Europe, Caucasia, and Central Asia, proposed by the WHO European Regional Office provides basic guidelines for this system and may be adapted to Russian conditions, as evidenced by the author's experience. The paper summarizes the basic results of the studies that have established the association of respiratory disease in junior schoolchildren with exposure to PM10 and PM2.5.

The antitoxic activity of several biological prophylactic complexes was studied in subchronic experiments on inbred albino rats exposed to a metal combination of leadchromium-arsenic-manganese-vanadium and benzo(a)pyrene, as well as phenol or naphthalene, and combinations of naphthalene-lead and phenol-naphthalene-lead. It has been shown that upon simultaneous exposure to the study combination of metals and organic poisons, it is advisable to use a biological prophylactic complex involving glutamic acid, a pectin enterosorbent, the multivitamin agent "Vitrum-Kids", calcium, vitamin C, glycine, methionine, and "Iodomarin".

The authors hold that an open discussion on the principles of and approaches to establishing the national standards of acceptable health risks should precede the official introduction of these standards into practice in taking decisions on risk management. They criticize the sociostatistical and socioeconomic concepts of risk acceptability as both amoral and impracticable and propose an approach based on the use of the Russian standards of permissible exposure levels (maximum permissible concentrations in particular) and on the exposure-response relationships established by epidemiological studies for the computation of responses (i.e. risk levels) corresponding to the permissible exposures. In some cases that such standards of an acceptable risk are too strict in existing technological or economic practice may be introduced in a stepwise fashion, but the risks that exceed the acceptable level should be compensated for.

The authors summarize theoretical principles of increasing human resistence to toxic effects of inorganic compounds polluting occupational environment and habitat, exemplify practical use of this prophylactic trend.

The authors hold that the maximum allowable concentrations (MAC) established in Russia for some ambient air pollutants can adversely affect human health and that they are worthy of reconsideration. This opinion is based on the published results of epidemiological studies of Western investigators and on the authors' own data obtained from the analysis by the time series method for a relationship of daily variations of dust or gaseous ambient air pollution to the so-called acute mortality or for that of the variations to respiratory symptoms and to the values of the maximum expiratory flow rate in preschool with or without respiratory abnormalities in their history; from the cross analysis of an association of the characteristics of atmospheric contamination in 13 urban areas with the prevalence of chronic respiratory diseases in junior schoolchildren, which was established by a special questionnaire. Particular emphasis should be laid on the reconsideration of not only established values, but mainly on the principles in laying down MAC for dust particles. The Western practice in measuring and evaluating risks separately for fractions of particles of varying sizes should be assessed for its use in Russian conditions; however, the authors' experience argues for this practice.

Dioxins and dioxin-like substances are highly toxic and extremely dangerous chemical compounds. Dioxins are formed during the thermal process associated with the use of chlorine. 2,3,7,8-tetrachlorodibenzo-1,4-dioxin is the most toxic, the most typical and well-studied agent. The most characteristic and constant indicators of intoxication with dioxin-containing substances are altered body weight, chloracne, hepatic damage, thyroid involution, structural changes in the adrenal cortex, spleen, genitals, immunodeficiency. There is evidence for a role of these agents in the development of infertility and neonatal pathology.

The paper provides evidence that there is a relationship of daily death rates to variations in the concentrations of total dust and some gaseous ambient pollutants. The great advantage of a procedure to analyze temporary variables is that it makes it possible to retrospectively use the available materials of routine monitoring of air pollution and to consider these effects (cases of death in particular). Along with the high informative value of environmental and epidemiological surveys (EES) based on the analysis of time series, this advantage allows one to recommend them for widely use within the sociohygienic monitoring system. At the same time the paper shows it necessary to control the quality of available data and to chose monitoring centers comparable in this regard. Inevitable missing data on the concentrations of different pollutants on days off and on some working days are of particular value under the actual conditions of monitoring of air pollution. The approach applied in this study to the choice of the most effective ways of filling of such gaps may be recommended. Nevertheless, incomplete data and the need for their artificial reproduction should be regarded as a source of uncertainty of specific results of EES of this type. Increments in mortality rates for a certain increase in the concentrations of pollutants may be used in the risk assessment projects when a dose-response relationship is analyzed. The larger number of EES based on the analysis of time series will be conducted in the regions of Russia, the more reliable the use of EES-grounded single risks will be at the regional and federal level.

Surveys made in the Sverdlovsk Region suggest that a procedure for evaluating a risk in combination with ecological and epidemiological surveys greatly enhances the potentialities of predicting and detecting human environment-related diseases and both approaches deserve a wide introduction into the socio-sanitary monitoring system.

The paper presents experimental and theoretical rationales for some methods and means of biological prevention of the toxic effects of a number of heavy metals (lead, chromium, arsenic, cadmium) that pollute the environment. Subchronic experiments were made on laboratory animals exposed to the above substances in combination with various biological agents (sodium glutaminate, the adaptogen saparal, pectin-containing enterosorbent, calcium, the multivitamin-multimineral preparation Pikovit, etc.). They have indicated that the complex use of preparations is more beneficial than they are used alone. The results of controlled trials of biologically preventive preparations on children residing in an area exposed to industrial pollution are presented.

The authors represent review of literature on fibrogenic effects of welding aerosols and results of own clinical and epidemiologic studies concerning pneumoconiosis course in electric welders compared to other occupational groups. In conclusion, the authors necessitate more strict control over total concentration of welding aerosol solid component (WASC) in air of workplace and determination of MAC for WASC.

Elevation of average daily concentrations of suspended particles in air, even being within the MAC, could be associated with higher mortality in general population and deteriorated respiratory symptoms in children, especially in those having chronic respiratory diseases with bronchial obstruction. Discussion on reduction of MAC for suspended particles is expendient with wider practice of fraction measurement their concentrations.

The authors represent a scheme of conceptual model for methodology to evaluate health risk caused by environmental pollution. The model is based on analysis of literature and the authors' experience.

The authors analyzed whether there is an association of mortality with ambient air pollution analyzed in Yekaterinburg and Nizhni Tagil in 1994 to 1997. There was a positive correlation between general mortality and CO or SO2 concentrations, between cardiovascular mortality and dust, NH3 or phenol, between mortality and CO or NH3. An increase of deaths as percents per 10 micrograms/m3 dust was calculated.

The studies conducted in Krasnouralsk (Sverdlovsk region) proved that environmental pollution with lead in the area subjected to releases by copper-melting enterprise creates significant risk of lead accumulation in preschoolers especially prone to unfavorable factors. Considering various environmental lead sources, biokinetic analog formation reliably forecasts serum lead levels. Soil polluted with lead, as the analog considers, is the most important environmental lead source. The authors suggest a system of prophylactic measures based on analysis of children's health risk caused by environmental pollution with lead.

With the help of mathematical methods of pattern recognition the analysis of complex cancer risk factors was conducted aiming at estimation the role of chronic radiation exposure in development of lung and breast cancer in dwellers of an industrial city exposed to irregular radioactive contamination as a result of an accident at PO "Mayak". It was shown, that chronic radiation exposure is an important factor, influenced the development of malignant neoplasms in city population.

Using a mathematical methodology based upon the theory of pattern recognition, the adequacy of this methodology being confirmed by the corroborative results obtained with neuro-net non-parametric methods of analysis, it proved possible to discriminate reliably between generalized organism's statuses, as described with a big number of laboratory indices, of the inhabitants of different areas of a big industrial city which differ in levels of radioactive and non-radioactive environmental pollution.

Experiments on white rats proved that the silicotic pulmonary changes slowed with the tails periodically immersed into iodine solution. Those pulmonary changes were due to inhalation of quartzite dust and especially due to intratracheal administration of standardized quartz dust DQ12. Influenced by inhalation of dust containing quartz, the rats demonstrated characteristic alterations in cytologic features of bronchial and alveolar lavage water. The "iodine baths" also declined those alterations, that may prove higher resistance of pulmonary macrophages to cytotoxic effects of quartz. This hypothesis finds a support in experiments with culture of rat peritoneal macrophages. If incubated in a medium with low iodine concentrations and subsequently washed off, the macrophages demonstrate lower incidence of cytotoxic effects due to the next incubation with particles of DQ12. The macrophage's higher resistance against cytotoxic agents is believed to result directly in antisilicotic effect of iodine, so "iodine baths" could be recommended for pathogenetic therapy and medical prophylaxis of silicosis.

The authors proved that animals having higher natural antioxidant activity and lower intensity of lipid peroxidation are more resistant to fibrogenic effects of quartz. The peritoneal macrophages obtained from those animals show higher resistance to quartz exposure "in vitro". Parameters characterizing antioxidant system should be included into a group of indexes describing propensity to silicosis.

The dermatoglyphic analysis of finger and palm prints was conducted in oncologic patients living in the same town and in corresponding with respect to the number control groups of inhabitants of the same town that were matched to each patient by the most relevant risk factors. The study was based on 61 dermatoglyphic characters. Using computer pattern recognition programs sufficiently informative subcomplexes of these characters were formed. They permitted to discriminate between ill and control persons.

Fifty-eight lung cancer and 71 gastric cancer patients were matched with corresponding healthy controls versus such risk factors as age, sex, nationality, tobacco smoking, alcohol drinking and occupation. HLA-antigens and dermatoglyphic patterns were used as genetic markers. Multivariate analysis employed mathematical procedures of pattern recognition. The results using HLA-antigen technique were not satisfactory. On the contrary, lung cancer studies based on 16 most informative dermatoglyphic parameters yielded reliable decision rules which proved 100% effective in control group and 83.3% effective in cancer patients. In gastric cancer studies, the best results (87.5% of correctly recognized patterns in both groups) were obtained, when 20 parameters were used. Correlations between pattern types and cancer of the lung and stomach have been identified. It is suggested that complete dermatoglyphic picture may be used as a marker of genetic predisposition to oncological disease.

The investigation concerning the dependence of cancer incidence on genetic HLA-markers and character of dermatoglyphs was carried out. The use of the pattern recognition method for multifactorial estimation of the above markers as well as the elimination of the main non-genetic oncogenic risk factors allowed obtaining the proof of the existence of the genetic predisposition to lung cancer. It was estimated that the character of dermatoglyphic prints is the most adequate marker for the investigated predisposition, and the reliable prediction of the genetic risk of the lung cancer development can be given as based on the joint evaluation of both markers.

Multichamber toxicokinetic model studies of the resorption, distribution and excretion properties of poorly soluble substances in subchronic action of suspensions administered intragastrically can be the first step in prognosing the toxicokinetic properties of the inhaled aerosols of the substances mostly discharged from the respiratory into the gastrointestinal tract (GIT). The generally accepted quantitative characteristics of the particles' deposition and translocation into GIT can provide a further application of the model for a mathematical description of a prolonged inhalational exposure to some substances. This technique was tested with the boron compounds characterized by low solubility and revealed a good correlation between the prognosed and actual deposits of the substance in the organ and excretions. At the same time, detected were some qualitative and quantitative differences in the boron toxicokinetics influenced by magnesium deboride and hexaborate, which were explained by differences in their solubility.

Acute toxicity, functional cumulative and local effects of the four ++poly-metallic oxides YBa2Cu3O7, Bi4Sr3O16, Tl2Ca2Cu3O10, Lao,7Sro,3CoO3, were studied in laboratory animals. Parallel experiments on assessment toxicity of the regular oxides of the studied metals in mice were carried out. The major dissolution of metals was shown to occur in acid medium. Thallium-barium-calcium cuprite turned out to be the most toxic and cumulative; it induced the most severe morphologic changes in the liver and kidneys. The least severe disorders caused by this substance were in the rat gastric mucosa and in rabbit eye after a conjunctival injection. Yttrium-barium cuprite induced the most severe changes at the site of injection, lanthanum-strontium cobaltite ranks second here. All copper-containing polymetallic oxides show resorptive toxicity when applied to the skin. Different types of combined toxicity are possible, that is why MACs for the regular oxides can not be used for setting the normal concentrations of ++poly-metallic oxides in air. Estimated toxicometric parameters helped to score the concentrations, which may serve as tentative safe levels of the studies substances.

The contributors propose a multichamber model for the assessment of dust particles' concentration, elimination and translocation in deep pulmonary zones. The choice of the model structure is dominated by the following criteria: that dust penetration into the interstitial pulmonary tissues and its translocation to the lymph nodes can be performed by non-phagocytized particle only; that these processes depend on the degree of dust-induced lesions in the macrophages and the growth of compensating neutrophilic phagocytosis; that part of the penetrating particles would continuously return to the free surface of the pulmonary zone together with the mobilized interstitial lung macrophages. The model adequately corresponds to the experimental data obtained in prolonged inhalation experiments, and imitates the kinetic effects related to severe damages and protection of the pulmonary clearance macrophage mechanisms.

Products of mouse peritoneal macrophage destruction (PMD) obtained by aseptic freezing-thawing of the cells, repeated thrice, were found to elicit in syngeneic mice injected with PMD intraperitoneally an increase of CFUs count in the hemopoietic bone marrow tissue and the spleen, as demonstrated by the Till and McCullooch technique. This proved to be a true increase since the transplatned stem cell fraction sorbed by the recipient's spleen was relatively lower in donor mice given PMD than in the control. Although PMD caused an increase of both erythropoietic (E) and granulocytopoietic-monocytic (G) colonies number, the E/G ratio was decreased; one of the mechanisms of the described effect could be the influence of PMD on the hemopoiesis-inducing microenvironment, as the same effects were obtained in mice injected repeatedly with PMD prior to the transplantation of bone marrow tissue of normal donors. Other possible mechanisms of these effects were analyzed, with consideration to the fact that in experiments with preincubation of bone marrow tissue with PMD prior to injection to the lethally irradiated mice no direct stimulating influence of PMD on the stem cell could be revealed.

Peritoneal macrophages (PM) of Wistar rats harvested after the intraperitoneal injection of paraffin oil were destroyed by repeated freezing-thawing. When injected intratracheally to control rats or to those after 4 daily exposured to TiO2 dust, these macrophage destruction products (MDP) caused a significant rise of both the alveolar macrophages (AM) and the neutrophilic leukocytes (NL) counts in the pulmonary washing-outs; the mean NL/AM ratio increased several times as compared to rats injected with normal saline intratracheally. Thus, the response to the inert dust particles plus the exogenous MDP became similar to the one observed after the cytotoxic (for instance silica) particles inhalation. Enhancing the NL contribution to the inhaled particles phagocytosis, the MDP led to a significant decrease of the mean "Dust load" of a single AM, although the total number of the engulfed particles increased. The predominant attraction of granulocytes and particularly of the NL as compared to the peritoneal macrophages was also found in the peritoneal exudates of rats injected with the MDP or silica suspension intraperitoneally, while the alveolar phagocytosis was not influenced. In vitro the MDP was shown to stimulate the NL migration and to facilitate the O2 consumption by PM. A possible role of the MDP as a multipotent controlling factor of phagocytosis response is briefly discussed.