1, i v(- Mr-w-:.-l.;~':"i'Il,""J"' ,""",, ' ------------"'-----------. .. tZtJi __ •••~ :. //~ •...\ (JL~ : \. '-----_ ..- .. A Study on Cancer Mortality in Tarapur-Based Atomic Energy Community KSV NAMBI, Ph.D. Y. S. MAYYA, M.Sc. D. D. RAO, M.Sc. S. D. SOMAN, M.Sc. Health and Safety Gro:lIp Bhabha Atomic Research Centre Bombay, India ABSTRACT.Cancer mortality risks for individuals who were employed at nuclear facilities' in Tarapur and for their respective family members with whom they lived were examined. Cancer deaths that occurred in this population between 1971 and1988 were compared with death rates published by the Bombay City Cancer Registry. Risks were expressed as standardized mortality ratios (SMRs), which were computed by dividing the observed number of deaths by the expected number of deaths and multiplying this value times 100. There ~iere 11 deaths from cancer among the employees, and this figure was too small to permit any trend analysis with respect to radiation exposures. The SMRs for allcancers and leukemia for male employees and for middle-aged male family members who were notex- posed to any radiation were not statistically significant. A much larger database of person years at risk would be required to reach definite conclusions. The combined cancer risks for employees and families combined were similar to risks experienced by individuals in Bombay. IN THIS STUDY, we examined the incidence of cancer deaths that occurred between 1971 and 1988 in employees at the Department of Atomic Energy (Tarapur) and in their respective, family membe'rs with whom they lived (i.e., "Tarapur-based DAE communi- ty"). All individuals resided approximately 10 km from the work site. Records of the DAE community are com- plete until the employees leave the Department's medical scheme or until death. The data on cancer deaths were based on the death certificates issued by well-recognized cancer hospitals in Bombay and other major cities where pat ents are invariably referred for diagnosis and treatment. The DAE complex in Tarapur houses a power station with a presently rated :apacity of 160x2 MWe, a fuel reprocessing plant, and a waste management facility. In 1988, approximately 2700 individuals were employed at thecomplex in Tarapur. Baseline cancer mortality data for persons who were not employed at DAE were not available; therefore, the cancer mortality data of theBombay city population was lIsed to compute the exped:ed number of cancer deaths in t~e study popula- tion. Bombay and Tarapur are cosmopolitan popula- tions that are separated by 100 km. Materials andmethods Theexpected number of cancerdeaths were com- puted with the age-specific cancerdeath rates published by the Bombay Cancer Registry; 1983 was thebaseline.!