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

A181

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 polycyclic aromatic hydrocarbons (PAH). 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 seven 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 (256 and 134 donors in study groups and controls, respectively). At the time of sampling all donors were adult and healthy. Both female populations were very homogenous. They included non-smoking 35-45 years old clerks with no occupational exposure to PAH compounds. Among men most of them were smokers and there were two general levels of exposure to PAHs. An extremely high occupational exposure (127 cokery workers) and, lower level, environmental exposure (129 residents of Silesia). The control group consisted of residents of rural part of Poland. Cancer incidence and mortality data, which are currently studied (11-17 years after sampling), are derived from the Silesia and Podlaska Cancer Registries, respectively. 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). The lack of the difference in cancer incidence between study group and control is justified by a relatively low exposure in both, very homogenous, populations. The rest of cases (18 out of 256, 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 number of cases observed in cokery worker's group (11 cases, 8.7%) is higher than in residents of Silesia (7 cases, 5.4%), observed cancer incidence 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 occupationally and environmentally exposed men from Silesia, as compared to controls, suggests causative relation between chemical exposure and cancer development.