The follow-up molecular epidemiology studies on humans exposed to environmental carcinogens in Upper Silesia, Poland.

B189

Silesia District is the most polluted industrial part of Poland. The major health hazard for humans comes from coal mining and/or processing, which generates chemical exposure. Among many chemicals are highly carcinogenic polycyclic aromatic hydrocarbons (PAHs). There were molecular epidemiology studies on residents of Silesia and rural controls performed in Poland between 1989 and 1995. As an outcome of these studies, significant damage to human genome was shown among residents of Silesia using eight different biomarkers. In order to answer the important question whether this damage corresponds to elevated risk of cancer a follow-up epidemiologic research has been started. The overall study population consists of 529 persons including 139 females (68 and 71 subjects in study group and control, respectively) and 390 males (255 and 135 donors in study groups and controls, respectively). At the time of sampling all donors were adult and healthy. Both female populations had relatively low exposure to chemical carcinogens and were very homogenous. They included non-smoking 35-45 years old clerks with no occupational exposure to PAHs. Among men most of them were smokers and there were two general levels of exposure to PAHs. An extremely high occupational exposure (169 cokery or coal mine workers) and, lower level, environmental exposure (86 residents of Silesia). The control group consisted of 135 residents of rural part of Poland (Podlaska District). Cancer incidence and mortality data for both study groups and control are currently derived from the Silesia and Podlaska Cancer Registries, respectively. The time difference between biomarkers study and present research (11-17 years) roughly covers the latency period for most of cancers. All together there are 21 cases of malignant neoplasm diagnosed in study groups and controls. Three out of 139 (2.1%) are females (1 and 2 cases in study group and control, respectively). There is no difference in cancer incidence between these two groups observed. The rest of cases (18 out of 255, 7.0%) belongs to the male populations from Silesia. It is interesting that there are no cancer cases found among men from rural control group. Although the percentage of cases observed in "occupationally" exposed group (13 out of 169, 7.7 %) is higher than among residents of Silesia (5 out of 86, 5.8 %), observed number of diagnosed subjects in so called "environmental" group is unexpectedly high. We realize, that these preliminary data need extended statistical evaluation but observed high number of cases among men from Silesia, as compared to controls, suggests causative relation between chemical exposure and cancer development.