Study Protocol for Radiation Exposure and Cancer Risk Assessment: The Taiwan Nuclear Power Plants and Epidemiology Cohort Study (TNPECS).

BACKGROUND: This cohort was established to evaluate whether 38-year radiation exposure (since the start of nuclear reactor operations) is related to cancer risk in residents near three nuclear power plants (NPPs). METHODS: This cohort study enrolled all residents who lived within 8 km of any of the three NPPs in Taiwan from 1978 to 2016 (n = 214,502; person-years = 4,660,189). The control population (n = 257,475; person-years = 6,282,390) from three towns comprised all residents having lived more than 15 km from all three NPPs. Radiation exposure will be assessed via computer programs GASPAR-II and LADTAP-II by following methodologies provided in the United States Nuclear Regulatory Commission regulatory guides. We calculated the cumulative individual tissue organ equivalent dose and cumulative effective dose for each resident. This study presents the number of new cancer cases and prevalence in the residence-nearest NPP group and control group in the 38-year research observation period. CONCLUSION: TNPECS provides a valuable platform for research and opens unique possibilities for testing whether radiation exposure since the start of operations of nuclear reactors will affect health across the life course. The release of radioactive nuclear species caused by the operation of NPPs caused residents to have an effective dose between 10-7 and 10-3 mSv/year. The mean cumulative medical radiation exposure dose between the residence-nearest NPP group and the control group was not different (7.69; standard deviation, 18.39 mSv and 7.61; standard deviation, 19.17 mSv; P = 0.114).

Assessment of resident doses near nuclear power plants in Taiwan for epidemiology study.

Dose assessments were required for the epidemiological study of residents living near nuclear power plants. In the present work, environmental pathway models have been applied to estimate radiation doses to residents living near the nuclear power plants in Taiwan. Best estimates of doses were made for residents by their age groups in different compass sectors centered at the nuclear power plants. In each sector, radiation doses were assessed using the averaged environmental, consumption and lifestyle data. For epidemiological analyses of cancer risks in different organs or tissues, individual organ absorbed doses were assessed for both the airborne and waterborne effluent releases. Such assessments were performed based on the historic data, including measured effluent releases, detected meteorological parameters, and surveyed data on the production and consumption of local agricultural, fishery and livestock products, etc. Exposure pathways consisted of the external irradiations from air submersion, ground deposition and water immersion plus the internal irradiations from inhalation and ingestion. Age-dependent annual intakes and occupancy time were locally surveyed. Dose conversion coefficients were taken from published data after International Commission on Radiological Protection Publication 60. Annual doses and cumulated doses during residence were assessed and examined for their dependence on age, organ and compass sector.