Conclusion

We found no statistical significant association between arsenic concentrations in Danish drinking-water and the risk for cancers of the lung, bladder, kidney, liver, prostate, or colorectum. The results indicated inverse associations between arsenic concentrations in Danish drinking-water and risk for skin cancers, suggesting that arsenic might have a protective effect at low concentrations. The results also indicated that arsenic in drinking-water might increase the risk for breast cancer. The findings should be interpreted with caution, and more studies are needed to confirm the results.