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This is the 14th report in a series of periodic general reports on mortality in the Life Span Study (LSS) cohort of atomic bomb survivors followed by the Radiation Effects Research Foundation to investigate the late health effects of the radiation from the atomic bombs. During the period 1950-2003, 58% of the 86,611 LSS cohort members with DS02 dose estimates have died. The 6 years of additional follow-up since the previous report provide substantially more information at longer periods after radiation exposure (17% more cancer deaths), especially among those under age 10 at exposure (58% more deaths). Poisson regression methods were used to investigate the magnitude of the radiation-associated risks, the shape of the dose response, and effect modification by gender, age at exposure, and attained age. The risk of all causes of death was positively associated with radiation dose. Importantly, for solid cancers the additive radiation risk (i.e., excess cancer cases per 10 4 person-years per Gy) continues to increase throughout life with a linear dose-response relationship. The sex-averaged excess relative risk per Gy was 0.42 [95% confidence interval (CI): 0.32, 0.53] for all solid cancer at age 70 years after exposure at age 30 based on a linear model. The risk increased by about 29% per decade decrease in age at exposure (95% CI: 17%, 41%). The estimated lowest dose range with a significant ERR for all solid cancer was 0 to 0.20 Gy, and a formal dose-threshold analysis indicated no threshold; i.e., zero dose was the best estimate of the threshold. The risk of cancer mortality increased significantly for most major sites, including stomach, lung, liver, colon, breast, gallbladder, esophagus, bladder and ovary, whereas rectum, pancreas, uterus, prostate and kidney parenchyma did not have significantly increased risks. An increased risk of non-neoplastic diseases including the circulatory, respiratory and digestive systems was observed, but whether these are causal relationships requires further investigation. There was no evidence of a radiation effect for infectious or external causes of death.

BackgroundThe accidents that occurred at the Fukushima Daiichi Nuclear Power Plant after the Great East Japan Earthquake on 11 March 2011 have resulted in long-term, ongoing anxiety among the residents of Fukushima, Japan. Soon after the disaster, Fukushima Prefecture launched the Fukushima Health Management Survey to investigate long-term low-dose radiation exposure caused by the accident. Fukushima Medical University took the lead in planning and implementing this survey. The primary purposes of this survey are to monitor the long-term health of residents, promote their future well-being, and confirm whether long-term low-dose radiation exposure has health effects. This report describes the rationale and implementation of the Fukushima Health Management Survey.MethodsThis cohort study enrolled all people living in Fukushima Prefecture after the earthquake and comprises a basic survey and 4 detailed surveys. The basic survey is to estimate levels of external radiation exposure among all 2.05 million residents. It should be noted that internal radiation levels were estimated by Fukushima Prefecture using whole-body counters. The detailed surveys comprise a thyroid ultrasound examination for all Fukushima children aged 18 years or younger, a comprehensive health check for all residents from the evacuation zones, an assessment of mental health and lifestyles of all residents from the evacuation zones, and recording of all pregnancies and births among all women in the prefecture who were pregnant on 11 March. All data have been entered into a database and will be used to support the residents and analyze the health effects of radiation.ConclusionsThe low response rate (<30%) to the basic survey complicates the estimation of health effects. There have been no cases of malignancy to date among 38 114 children who received thyroid ultrasound examinations. The importance of mental health care was revealed by the mental health and lifestyle survey and the pregnancy and birth survey. This long-term large-scale epidemiologic study is expected to provide valuable data in the investigation of the health effects of low-dose radiation and disaster-related stress.

Objective To investigate the degree to which ionising radiation confers risk of mortality from heart disease and stroke. Design Prospective cohort study with more than 50 years of follow-up. Setting Atomic bomb survivors in Hiroshima and Nagasaki, Japan. Participants 86 611 Life Span Study cohort members with individually estimated radiation doses from 0 to >3 Gy (86% received <0.2 Gy). Main outcome measures Mortality from stroke or heart disease as the underlying cause of death and doseresponse relations with atomic bomb radiation. Results About 9600 participants died of stroke and 8400 died of heart disease between 1950 and 2003. For stroke, the estimated excess relative risk per gray was 9% (95% confidence interval 1% to 17%, P=0.02) on the basis of a linear dose-response model, but an indication of possible upward curvature suggested relatively little risk at low doses. For heart disease, the estimated excess relative risk per gray was 14% (6% to 23%, P<0.001); a linear model provided the best fit, suggesting excess risk even at lower doses. However, the dose-response effect over the restricted dose range of 0 to 0.5 Gy was not significant. Prospective data on smoking, alcohol intake, education, occupation, obesity, and diabetes had almost no impact on the radiation risk estimates for either stroke or heart disease, and misdiagnosis of cancers as circulatory diseases could not account for the associations seen. Conclusion Doses above 0.5 Gy are associated with an elevated risk of both stroke and heart disease, but the degree of risk at lower doses is unclear. Stroke and heart disease together account for about one third as many radiation associated excess deaths as do cancers among atomic bomb survivors.

The heart has traditionally been considered a radio-resistant organ that would be unaffected by cardiac doses below about 30 Gray. During the last few years, however, evidence that radiation-related heart disease can occur following lower doses has emerged from several sources. These include studies of breast cancer patients, who received mean cardiac doses of 3–17 Gray when given radiotherapy following surgery, and studies of survivors of the atomic bombings of Japan who received doses of up to 4 Gray. At doses above 30 Gray, radiation-related heart disease may occur within a year or two of exposure and risk increases with higher radiotherapy dose, younger age at irradiation, and the presence of conventional risk factors. At lower doses the typical latent period is much longer and is often more than a decade. However, the nature and magnitude of the risk following lower doses is not well characterized, and it is not yet clear whether there is a threshold dose below which there is no risk. The evidence regarding radiation-related heart disease comes from several different disciplines. The present review brings together information from pathology, radiobiology, cardiology, radiation oncology and epidemiology. It summarises current knowledge, identifies gaps in that knowledge, and outlines some potential strategies for filling them. Further knowledge about the nature and magnitude of radiation-related heart disease would have immediate application in radiation oncology. It would also provide a basis for radiation protection policies for use in diagnostic radiology and occupational exposure.