[Instability and sensitivity of the genome of healthy children in Magnitogorsk].

Problem of the influence of factors of the industrial city on the hereditary apparatus of its residents has not been fully resolved, because of traditionally in such studies only the pollution of environment components is taken into account. However the existence of a set of contributing socialfactors that modify the genotoxic effects ofpollution, requires the creation of a new methodology for genetic and toxicological studies. For this purpose, in Magnitogorsk, where one of Russia's largest steel plants is located, we conducted a comprehensive survey, whose tasks included the analysis of the influence of the complex of exogenous and endogenous factors on the genome of children. In this publication there are presented the results of the fifth fragment of this work - the analysis of instability and individual sensitivity of the genome of 166 children of 5-7 years, residing in two districts of Magnitogorsk: around the steel plant and on the opposite bank of Ural river, where there are no large-scale industrial enterprises. The study was conducted in the micronucleus test on peripheral blood lymphocytes cultured with cytochalasin B. For assessment of individual sensitivity of genome blood cultures were exposed to standard N-methyl-N-nitro-N-nitrosoguanidine (MNNG) mutagen. Cytogenetic analysis was performed in binucleated cells accordingly to international protocol, as well as with the use of an extended protocol including 32 indices. Average group frequency of binuclear cells with micronuclei (0.5-0.7%) were found not differ from the levels defined in children residing in Europe, and not differ between areas of the town. However the extended protocol of cytogenetic analysis discovered that the real frequency of dividing cells with lesions in blood cultures of children was 1,49-1,66%. Higher spontaneous proliferative activity of the cells and the frequency of dividing cells with injuries were found in blood cultures of children residing in settlements around the Magnitogorsk steel plant, while the individual sensitivity of the genome in these children was lower than that of their peers from the opposite bank of the Ural river A similar conclusion, but already in relation to the state of the systems for adaptation of entire body has been made from results of other fragments of the study, published earlier.

[Detection of potentially carcinogenic compounds persisting in atmospheric air and having high priority for hygienic regulation].

The algorithm for the choice of potentially carcinogenic compounds (PCS) among emitted into air and results of the study, undertaken for realization of this algorithm are presented. The investigation was carried out in Magnitogorsk - Russian town of black metallurgy - in frames of the other study, aimed to evaluation of the influence of atmospheric pollution on children's health and genomic instability. The 11 PCS for further profound study of biological activity were selected out of more than 300 PCS, persisting in the air. The carcinogenic activity for 6 compounds out of these 11 ones was already have been found out before, that testifies correctness of the created approach and its adequacy for detection PCS in atmospheric air.

[Characteristics of quantitative values of regional factors of exposure in the studied areas].

In the paper the results of a comparative evaluation of the Russian and the standard, recommended by US EPA, factors of population exposure in seven areas of different federal districts of Russia are presented. Concerning the adult population differences reach 3.5 times, for children (1-6 years) - 4.2 times. An example of the effect of regional differences and standard factors on levels of exposure and risk is considered. Promising areas for further research on regional factors to improve the accuracy and reliability of the forecast assessments of the risks to public health have been identified.

[Morbidity among senior preschool children in Magnitogorsk].

The publication is the third fragment of the multiparameter study. The level and causes of genome instability and sensitivity are assessed in children living in Magnitogorsk, a city with one of the largest mills in Russia. The city is in the list of the world's 35 most polluted ones. A transverse retrospective analysis found no differences in primary morbidity among 5-7-year-old children who had been living in different districts of Magnitogorsk since birth and were going to municipal kindergartens located adjacent to their house. Contrary to the expectations, the prevalence of morbidity and diseases that were markers for an industrial town was significantly lower among the children residing in the settlements situated around the mills than that in the city's other districts. There were 9 organic compounds that had no hygienic standards, the content of which in the snow samples collected in the areas of the examined kindergartens correlated with the prevalence of the children's morbidity. Family social and living conditions were shown to affect the children's morbidity.

[Hygienic evaluation of the total mutagenic activity of snow samples from Magnitogorsk].

The paper gives the results of 4-year monitoring of the total mutagenic activity of snow samples from different Magnitogork areas in a test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster. An association was first found between the rate of DLM and the content of some chemical compounds in the ambient air and snow samples; moreover all the substances present in the samples, which had found genotoxic effects, showed a positive correlation with the rate of DLM. Furthermore, direct correlations were first established between the rate of DLM and the air pollution index and morbidity rates in 5-7-year-old children residing in the areas under study. The findings allow the test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster to be recommended due to its unique informative and prognostic value for monitoring ambient air pollution and for extensive use in the risk assessment system.

[Estimation of adaptive capacities in Magnitogorsk children from the activity of some detoxification enzymes].

The paper provides the first fragment of a multiparameter study analyzing the influence of environmental pollution, the social and psychological features of a family, and some endogenous factors on genome stability and sensitivity in a developed ferrous metallurgy town. It also gives data on the urine and serum activity of the lysosomal enzyme N-acetyl-b-D-glucosaminidase (NAG) and the serum activity of catalase in an organized contingent of apparently healthy children (n = 178; 6 kindergartens) aged 5-7 years, who live permanently in Magnitogorsk at different distances from the metallurgical works. More than 70% of children selected for examination were found to have average normal levels of activity of the enzymes studied. According to the average levels of enzyme activity, there were only 2 kindergartens (both from the left-bank region). In the children from the left-bank area, enzyme activities varied more greatly, which suggests the higher prevalence of tense adaptation. Correlation analysis revealed association between the children's serum activity of enzymes and some components of snow pollution. It is anticipated that the found changes in serum activities of N-acetyl-beta-D-glucosaminidase and catalase may be determined by individual differences in a child's response to ambient air pollutants.