[Breast cancer in Chapayevsk]. / Rak molochnoi zhelezy v Chapaevske.

Numerous epidemiological surveys show the ambiguity of evaluation of stable organic chlorine compounds as a risk factor for breast cancer (BC). This is likely to be, to a certain degree, associated with the specific features of performance of epidemiological surveys. The selection of cases of BC from different areas has provided groups with different levels of exposure that as judged from the content of the above substances in the biological environments. Only few epidemiological surveys have been made in the world to assess stable organic pollutants (SOP) as risk factors of BC mainly in occupational groups. In the local areas highly polluted with dioxins, there is evidence for their role as a risk factor of BS only for women living in Sevezo. These findings are in agreement with the results of the surveys made in Chapayevsk. The analytical epidemiological study using a case-control approach has revealed the significance of biological (BC in relatives, childlessness), occupational (women's work at CVZH) and environmental (pollution, the more frequent ingestion of local pork and fish than in the control group) risk factors of BC. In the 1950-1960s, the largest Russian enterprises of chlorine chemistry worked most actively not only in Chapayevsk, but also in towns with plants of chlorine industry, such as Dzerzhinsk, Novomoskovsk, Sayansk, Usolye-Sibirskoye, and others. Ecological and epidemiological studies should be organized in these towns in order to define the value of SOP as a risk factor of BC for general populational groups.

[Effects of dioxins in the development of malignant tumors and disorders of reproductive health of the population]. / O vliianii dioksinov na vozniknovenie zlokachestvennykh novoobrazovanii i narushenii reproduktivnogo zdorov'ia naseleniia.

The mortality caused by malignant tumors in the town of Chapaevsk, characterized by increased level of dioxins in the environment, is statistically higher than the expected values. For men the relative risk of general morbidity is 1.9 and mortality, 1.8; for lung cancer: morbidity, 3.3 and mortality 3.1; for urogenital cancer: morbidity, 3.6 and mortality, 2.6; for gastric cancer: morbidity 1.9 and mortality, 1.7. In women the morbidity and mortality due to breast cancer (relative risks 1.9 and 2.1, respectively) and cancer of the cervix uteri (relative risks 2.1 and 1.8, respectively) are increased. Changes in the reproductive health of residents of this town are as follows: high incidence of spontaneous abortions, appearance of small-for-date babies, and genital disorders in body (cryptorchidism, phimosis, hypospadia, delayed sexual development).

[Dioxins in the environment and in the blood and breast milk of residents of the town of Chapayevsk]. / Dioksiny v okruzhaiushchei srede, v krovi i grudnom moloke zhitelei goroda Chapaevska.

Chapayevsk has a 30-year history of producing organochlorines, leading to environmental dioxin pollution. As much as 3 kg of these substances are annually formed at the plant. The concentrations of dioxins in the ambient air were found to be 0.001 to 1.13 pg/m3, in 1-TEF dioxin equivalent or 0.00001-1.76 pg/m3, as calculated by using WHO-TEF for dioxin-like compounds, those in the urban drinking water were 0.1 to 20.83 pg/liter, in the soil near the plant, 141 ng TEQ/kg, by decreasing to 37 ng/kg in the downtown (2-7 km from the plant) and 4 ng/kg at a distance of 7-10 km from the plant, their levels in the vegetables and fruits were 0.002 to 10.6 pg/kg. The direct indicator of dioxin exposure is its detection in human breast milk and blood. Examination of the content of dioxins in the breast milk of Chapayevsk women versus those living in other towns and cities of Russia has shown considerably higher levels of dioxins, such as 2,3,7,8-TCDD, 1,2,3,7,8-PCDD, 1,2,3,4,7,8-GCDD, and octa-dioxins. The mean content of dioxins in the breast milk (7 pooled samples from 40 individual trials) was 43.3 pgTEQ/fat. It is significantly higher than that detected in the populations of other Russian territories and other countries. The mean blood concentrations of dioxins in peoples living near the plant was 75.2 pgTEQ/fat, those were lower (24.5 pgTEQ/fat) in those living at 5-7 km of the plant.