Körblein A, Hoffmann W. Background radiation and cancer mortality in Bavaria:
an ecological analysis.
Arch Environ Occup Health. 2006 May-Jun;61(3):109-14.


The authors investigated a possible association between background gamma radiation (BGR) and cancer and infant mortality rates. In an in-country ecological study, they performed a population-weighted linear regression of cancer (infant) mortality rates on BGR, adjusted for unemployment rate and population density. Crude cancer rates showed a highly significant increase with BGR: 38 excess cases per 100,000 person-years per millisievert/year (p < .0001).
After adjusting for unemployment rate and population density, the authors found that the excess absolute risk reduced to 23.6 cases per 100,000 person-years per mSv/year (p = .0014). The corresponding excess relative risk was 10.2% (95% confidence interval = 3.9-16.7) per mSv/year. The excess relative risk for infant mortality rates was 24% (95% confidence interval = 9-42) per mSv/year. The cancer risk derived from this ecological study is 0.24/Sv, which compares with an International Commission on Radiological Protection value of 0.05/Sv. However, because they are based on highly aggregated data, the results should be interpreted with caution.

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