ABSTRACT
OBJECTIVE: To determine postaccident changes in health status of the Chornobyl cleanup workers 1986 1987, pecu liarities of nontumor incidence. MATERIALS AND METHODS: Long term cohort epidemiological study (period of observation 1988-2012) has been con ducted using data of the State Registry of Ukraine of Persons Affected by the Chornobyl Accident. Study cohort - 196,423 males participants of the Chornobyl recovery operations in 1986-1987. Epidemiological and mathematical and statistical methods were used. RESULTS: We have found a dramatic deterioration of the Chornobyl cleanup workers' health due to the growth of wide range of nontumor diseases, especially circulatory, digestive, respiratory, endocrine, genitourinary and nervous sys tem diseases. In postaccident period, disability and mortality have increased significantly due to nontumor dis eases. Circulatory diseases make major contribution to the structure of causes of disability and death. When study ing the dynamics of nontumor incidence, we have found that in 1988-1992 the highest, throughout postaccident period, rate of mental and behavioral disorders, diseases of the nervous system was mainly due to disorders of the autonomic nervous system. Since 1993-1997, rate of this pathology has significantly reduced and remained stable in subsequent years of observation. Thus, we can assume that in the early postaccident period, stress factor in com bination with radiation one had the greatest impact on health of cleanup workers, resulting in the development of other nontumor diseases in the remote postaccident period. CONCLUSIONS: The study revealed an evident increase in nontumor incidence, disability and mortality from nontumor diseases among Chornobyl cleanup workers 1986-1987; the highest rate of nontumor incidence was observed 12-21 years after the Chornobyl accident.
ABSTRACT
The characteristics of the contamination resulting from the Chernobyl accident are defined, as a basis for epidemiological investigations. Due to loss of integrity of the nuclear fuel and thermal buoyancy from fire and nuclear heating, a large quantity of radioisotopes were released over a period of up to 16 days. The areas affected were very large, 37 million hectares in Ukraine alone. About 5 million persons were affected in one way or another, over 2 million of them in Ukraine. For registration and follow-up of health consequences from the accident, 4 main groups were distinguished, namely: (1) the participants in the containment of the accident and its cleanup ("liquidators"); (2) evacuees; (3) residents of contaminated areas; and (4) children born to parents with significant radiation exposure. Registration and epidemiological follow-up in the former USSR and the three republics afterwards are presented with an emphasis on Ukraine. Considering the long incubation times for some of the expected illnesses and relatively low average doses, the difficulties of confirming significant effects become evident. For example leucosis morbidity among cleanup personnel within a 30 km zone around the accident was 3.4 per 100,000 before the accident and 7 per 100,000 afterwards. The question of the statistical significance of such numbers is discussed by the authors, in the context of confounding factors. For some of the observed effects it has already been established that stress and anxiety caused by the accident and living conditions in the affected areas are the principal cause rather than radiation. According to the authors, more detailed retrospective and prospective epidemiological studies are needed in the future, in order to clarify the causes of observed health effects.
