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.