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Biomedical subjects

C R Muirhead

Publications and source records attributed to C R Muirhead.

44 records · Page 3Linked to original sources
PubMed1988

A summary of mortality and incidence of cancer in men from the United Kingdom who participated in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes.

Altogether 22,347 men who participated in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes in Australia and the Pacific Ocean between 1952 and 1967 were identified from the archives of the Ministry of Defence and followed up. Their mortality and incidence of cancer were compared with those in 22,326 matched controls selected from the same archives. The risk of mortality in the participants relative to that in the controls was 1.01 for all causes and 0.96 for all neoplasms. Thirty eight causes of death were examined separately. Significant differences in mortality were found for leukaemia, multiple myeloma, and other injury and poisoning, with higher rates in the participants, and for cancers of the prostate and kidney and chronic bronchitis, with higher rates in the controls. The mortality from leukaemia and multiple myeloma in the participants was slightly greater than would have been expected from national values (standardised mortality ratios of 113 and 111, respectively), but in the controls it was substantially lower (standardised mortality ratios of 32 and 0, respectively). Examination of the rates of leukaemia and multiple myeloma in groups of participants showed very little difference between groups characterised by recorded doses of external radiation or type of test participation and failed to indicate any specific hazard. Evidence obtained from participants who reported themselves voluntarily (or were reported by relatives or friends) suggested that 17% of participants may have been omitted from the main study group but that any resulting bias was small. Most of the differences observed between the participants and controls were interpreted as due to chance, but some may be due to differences in smoking habits. Participation in the test programme did not seem, in itself, to have caused any detectable effect on the participants' expectation of life, apart from possibly causing small risks of developing leukaemia and multiple myeloma.

Environmental Exposure↗
PubMed1988

The risk of leukemia in Seascale from radiation exposure.

An excess of leukemias in children has been observed between 1950 and 1980 in the village of Seascale (population about 3,000) which is situated approximately 3 km to the south of Sellafield nuclear fuel reprocessing plant in West Cumbria, England. Radiation doses from all the main sources of radiation exposure of the population and risks of radiation-induced leukemia have been calculated for children born and living in Seascale during the period of operation of the plant. For the Seascale study population of 1225 children and young persons, followed to age 20 y, or followed until 1980 for those born after 1960, 0.016 radiation-induced leukemias are predicted from the Sellafield discharges. This corresponds to an average risk to children in the population of about one in 75,000. For the four fatal leukemias observed in the study population (0.5 expected from United Kingdom statistics) to be attributed to the operations at Sellafield, the average risk would have to be increased by a factor of about 250, to one in 300. Although there is some uncertainty about the releases from the plant and concentrations of radionuclides in environmental materials in the Sellafield area, particularly for the early years of its operation, the possibility that the doses calculated and the risk coefficients used for radiation-induced leukemia could be so substantially wrong is very unlikely. The number of radiation-induced leukemias from all radiation sources is calculated to be 0.1, which corresponds to a risk of about one in 12,250 for the average child in the study population. About two-thirds of the risk is from natural radiation, 16% from the Sellafield discharges, and nuclear weapons fallout and medical exposure each contribute about 9%. The models used for calculating radiation doses from intakes of radionuclides were based upon those recommended by the International Commission on Radiological Protection (ICRP). This presented a number of difficulties in the assessment, which included the lack of any generally accepted age-related dosimetric models, particularly for bone-seeking radionuclides; limited information on gut transfer factors for radionuclides incorporated in foodstuffs; and no dosimetric models for the fetus. These and other problems identified in the analysis that require more information are discussed.

Air Pollutants, Radioactive↗