Environmental pollution in central and eastern European countries: a basis for cancer epidemiology.

The main objective of this paper is to discuss the environmental issues in the countries of central and eastern Europe (CCEE) and to show their significance for cancer epidemiology. Of known cancer risk factors that may be related to environmental exposure in the CCEE, tobacco smoking is probably the most important. The worsening trends in cancer mortality noted in middle-aged men in the CCEE can be attributed to smoking. Other lifestyle factors that interact with environmental hazards include high alcohol consumption and unhealthy nutrition. Among other factors, the most common environmental exposure in the CCEE that has potential adverse effects on health in terms of cancer incidence is related to high levels of ambient and indoor pollutants exceeding the air quality guidelines of the World Health Organization. Millions of people, usually in urban areas, are estimated to be exposed to such levels of pollution. Outdoor air pollution is a substantial environmental problem in many areas of the CCEE, where heavy industries are concentrated without adequate technology for emission control. Chemically contaminated drinking water provides a major route of exposure for many potential environmental health hazards. The pollution of water resources, including groundwaters, by industrial and agricultural wastes is a widespread problem in both the CCEE and the former USSR. An estimated 13% of treatment plants in the Russian Federation lack the necessary equipment to treat drinking water, particularly for disinfection, to meet the required standards. Many countries in the region have problems in rural areas, where the networks are small or consumers depend on private wells, and treatment of drinking water is either poor or nonexistent. Consequently, because the standards are difficult to meet, drinking-water accumulates high levels of arsenic and nitrates. The main concern is nitrate, arsenic, fluoride, and pesticides. In countries like Bulgaria, Hungary, Romania, and Slovakia, locations are known where nitrate concentration in drinking water are high enough to cause methemoglobinemia. Lack of appropriate data hamper valid estimates of the extent of unhealthy working conditions or of poor housing conditions. Unsafe industrial installations are potential environmental health hazards, the possible scale of which is difficult to estimate reasonably.