Cancer consequences of the Chernobyl accident in Europe outside ...

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Jul 29, 1996 - OUTSIDE THE FORMER USSR: A REVIEW. Davide SALI'aZ ... Outside the 3 most affected states of Belarus, Russia and. Ukraine, activities to ...
Int. J. Cancer: 67,343-352 (1996) 0 1996 Wiley-Liss, Inc.

Publication of the International Union Against Cancer Publication de I'Union Internationale Contre le Cancer

CANCER CONSEQUENCES OF THE CHERNOBYL ACCIDENT IN EUROPE OUTSIDE THE FORMER USSR: A REVIEW Davide SALI'aZ,Elisabeth CARDIS','s, Laszlo SZTANYIK3,Anssi AUVINEN4,Antonina BAIRAKOVA~, Nicolas DONTAS~, Bernd GROSCHE', Andor KEREKES3,Zvonko KuSrcs, Cemil KUSOGLU~, Stanislav LECHPAMMER~, Maria LYRAIO, Jorg MICHAEL IS^^, Eleni PETR1DOU1*,Zbigniew sZYBINSKIl3,Suketami T0MINAGAl4,Rodica T U L B U R E ~ ~ , Archie TURN BULL'^ and Zdravka vALERIANOVA17 'Programme on Radiation and Cancer, International Agency for Research on Cancer, Lyon, France; 2SezioneMedicina Preventiva dei Lavoratori, University of Pavia, Pavia, Italy; 3National Research Institute for Radiobiology and Radwhygiene, Budapest, Hungary; 4Finnish Centerfor Radiation and Nuclear Safety, Helsinki, Finland; 5National Center of Radiobiology and Radiation Protection, Sofia, Bulgaria; 6HellenicCancer Society, Athens, Greece: 71nstitutefor Radiation Hygiene, Oberschleissheim, Germany; aDepartment of Oncology and Nuclear Medicine, University Hospital "Sestre Milosrdnice': Zagreb, Croatia; YDepartmentof Radiation Oncology, Ankara Oncology Hospital, Ankara, Turkey; lODepartment of Radiology and Radiation Physics, Araeteion Hospital, University of Athens, Athens, Greece; "Institute for Medical Statistics and Documentation, University of Mainz, Mainz, Germany; l2Depaifment of Hygiene and Epidemiology, Athens UniversityMedical School, Athens, Greece; I3Departmentof Endocrinology, Collegium Medicum, Jagiellonian University, Cracow, Poland; I4Aichi Cancer Center, Nagoya, Japan; 151nstituteof Hygiene, Public Health, Health Services and Management, Bucarest, Romania; %temational Union Against Cancer, Geneva, Switzerland; "Department of Epidemiology, National Oncological Center, Sofia, Bulgaria. The accident which occurred during the night of April 25-26, 1986 in reactor 4 of the Chernobyl nuclear power plant in the Ukraine released considerable amounts of radioactive substances into the environment. Outside the former USSR, the highest levels of contamination were recorded in Bulgaria, Austria, Greece and Romania, followed by other countries of Central, Southeast and Northern Europe. Studies of the health consequences of the accident have been carried out in these countries, as well as in other countries in Europe. This report presents the results of a critical review of cancer studies of the exposed population in Europe, carried out on the occasion of the 10th anniversary of the Chernobyl accident. Overall, there is no evidence to date of a major public health impact of the Chernobyl accident in the field of cancer in countries of Europe outside the former USSR. 0 1996

Group, 19911. These studies have focused on various possible health consequences of the accident, ranging from changes in birth rates to adult cancer. Some have been published, while others are ongoing. The current report presents a critical review of cancer studies, carried out on the occasion of the 2nd International Union Against Cancer (UICC) Workshop on the Long-Term Follow-Up of the Chernobyl Disaster, held in Athens, Greece on November 27-29.1995. A detailed presentation of the individual studies can be found in the proceedings of that workshop (UICC-HCS, 1996) and in published reports (Petridou et al., 1994; Auvinen et al., 1994; Hjalmars et al., 1994; Michaelis et al., 1996; Esik and Nemeth, 1994; Danon et al., 1992). The focus of the review is cancer.

Wiley-Liss,Inc. BACKGROUND

The Chernobyl accident, which occurred in April 1986 and resulted in widespread contamination with radionuclides, has generated much concern about its health consequences in the populations reached by the radioactive clouds. Following the accident, a number of programmes to monitor its health consequences were started. Most of them focused on the most contaminated regions surrounding the damaged reactor, in the Ukraine, Belarus and the Russian Federation. Others concerned the remaining European countries. In the former USSR, these programmes included national initiatives in the affected states, international programmes such as the International Chernobyl Project of the International Atomic Energy Agency (IAEA) (International Chernobyl Project, 1991), the International Programme on the Health Effects of the Chernobyl Accident (IPHECA) (WHO, 1995) and the International Thyroid Project (ITP) of WHO (World Health Organization European Centre for Environment and Health, 1993), as well as multilateral and/or bilateral collaborations among the Ukraine, Belarus or Russia and the European Commission, the United States, Japan, Germany, France and a number of other countries. Outside the 3 most affected states of Belarus, Russia and Ukraine, activities to evaluate or mitigate the consequences of the accident have mainly been carried out at local or national levels [apart from the European Childhood Leukaemia and Lymphoma Incidence Study (ECLIS; Parkin et al., 1993, 1996) and the study of the European Registration of Congenital Anomalies and Twins (EUROCAT EUROCAT Working

Radiation and health Ionising radiation is one of the most studied and best quantified carcinogenic agents in our environment (US NAS, 1988; US NAS, 1990; UNSCEAR, 1994). Cancer is the main long-term consequence of exposure to ionising radiation. Although the risk of cancer can be increased by exposure in virtually every tissue of the human body, organs vary with respect to their radiosensitivity. Overall, leukaemia, excluding chronic lymphocytic leukaemia (CLL), is one of the cancers most strongly related to radiation exposure, and numerous studies have shown that radiation-related increases in the risk of this disease can be observed soon, as early as 2-5 years after exposure (UNSCEAR, 1994). For most other cancers, the time between an exposure and the resulting neoplasm appears to be longer, 10 years or more (UNSCEAR, 1988). Exposure in childhood entails a greater risk than exposure in later life for a number of cancers, particularly thyroid cancer (UNSCEAR, 1994; Shore, 1992). In the last 3 years, reports (Kazakov et al., 1992; Demidchik et al., 1994) of a large increase in thyroid cancer incidence in children, particularly in the Gomel area of Belarus, have been

'*To whom correspondence and reprint requests should be addressed, at the RCA-IARC, 150 Cours Albert Thomas, 69 372 Lyon Cedex, France. Fax: (33) 72 73 85 75. Received: March 14,1996.

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published. They were initially met with scepticism, because of the early occurrence of the increase (as early as 4 years after the accident) and the very high incidence of the disease reported [annual age-specific incidence in children under the age of 15 in 1991-1994: 9.6 in 100,000 in Gomel region and 2.9 in 100,000in Belarus as a whole (Stsjazhko et aL, 1995)l. Since then, increases have, however, also been reported in the Ukraine (Tronko et aZ., 1994) and in the part of Russia most contaminated by the accident (Tsyb et al., 1994; Stsjazhko et al., 1995). Average levels of radiation exposure and dose in European countries have been published by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (UNSCEAR, 1988) and by national and local organisations. First-year and committed doses estimated from UNSCEAR are summarized in Table I by large geographical areas. The average first-year thyroid dose equivalents for infants and adults and effective dose equivalents (DE) for populations in individual contaminated countries in Europe are shown in Table 11. Because the geopolitical situation has changed in Europe since the publication of the UNSCEAR (1988) report, Table I1 presents doses for the countries of Europe as currently defined; these values have been derived by extrapolation (on the basis of the size of the country and of its population) from the original UNSCEAR data. On the basis of these dose levels, it has been estimated that, in Europe outside the former USSR, an additional cancer mortality of up to 0.018% could be expected (Sztanyik, 1991). Increases of this magnitude would be very difficult to detect epidemiologically. However, both the population and local public health authorities have considerable concern concerning the consequences of the accident. Ten years after the Chernobyl accident it is useful to review the results of one decade of studies of cancer risk carried out in Europe after the accident to judge whether this concern is fully justified.

UICC Workshops on the Long-TermFollow-Up of the Chernobyl Disaster In 1991, the UICC, in collaboration with the Hellenic Cancer Society, organised a 1st Workshop to review the consequences of the Chernobyl accident in the most contaminated countries of Europe, outside the USSR (UICC-HCS, 1991). Although much information was presented concerning levels of contamination measured in these countries, little concrete information was available on the health impact on the population. The feasibility and cost of studies of relatively low levels of radiation were discussed, and the meeting concluded with recommendations concerning: Passive monitoring of the health of populations through population-based disease registries; TABLE I- REGIONAL AVERAGE EFFECTIVE DOSE EQUIVALENTS IN EUROPE DUE TO THE CHERNOBYL ACCIDENT'

North Central Southeast West Southwest Altogether

1.0 7.65 10.7 1.25