Association between drinking water uranium content and cancer risk in Bavaria, Germany

To evaluate the possible association between uranium (U) content in public drinking water on the one hand and the risk of cancer of the colorectum, lung, female breast, prostate, kidney, and urinary bladder, total cancer, and leukemia on the other hand in Bavaria, an ecologic study on the level of municipalities was performed.

Cancer incidence data for the years 2002-2008 were obtained from the population-based cancer registry Bavaria according to sex. Current U content data of public drinking water on the level of municipalities were obtained from a publicly available source. The possible association between drinking water U content and cancer risk adjusted for average socio-economic status was evaluated using Poisson regression.

Drinking water U content was below 20 μg/L in 458 out of 461 included municipalities. We found a significantly increased risk of leukemia in men in the intermediate (U level, 1.00-4.99 μg/L; relative risk [RR], 1.14) and in the highest U exposure category (U level, ≥5 μg/L; RR, 1.28). Moreover, in women, a significantly elevated risk was identified with respect to kidney cancer in the highest exposure category (RR, 1.16) and with respect to lung cancer in the intermediate exposure category (RR, 1.12).

The slightly increased risk of leukemia in men, kidney cancer in women, and lung cancer in women may require further investigation. If an increased cancer risk is confirmed, preventive measures (e.g., introduction of U filters in public water systems) may be considered.