title: Uranium and other natural radionuclides in drinking water and risk of leukemia: a case-cohort study in Finland.
abstract: OBJECTIVE
  We assessed the effect of natural uranium and other radionuclides in drinking water on risk of leukemia.
  
  
  METHODS
  The subjects (n = 144,627) in the base cohort had lived outside the municipal tapwater system during 1967-1980. A subcohort was formed as a stratified random sample of the base cohort and subjects using drinking water from drilled wells prior to 1981 were identified. A case-cohort design was used comparing exposure among cases with leukemia (n = 35) with a stratified random sample (n = 274) from the subcohort. Activity concentrations of uranium, radium-226, and radon in the drinking water were analyzed using radiochemical and alpha-spectrometric methods.
  
  
  RESULTS
  The median activity concentration of uranium in well water was 0.08 Bq/L for the leukemia cases and 0.06 Bq/L for the reference group, radon concentrations 80 and 130 Bq/L, respectively, and radium-226 concentrations 0.01 Bq/L for both groups. The hazard ratio of leukemia for uranium was 0.91 (95% confidence interval 0.73-1.13) per Bq/L. for radon 0.79 per Bq/L (95% CI 0.27-2.29), and for radium-226 0.80 (95% CI 0.46-1.39) per Bq/L.
  
  
  CONCLUSIONS
  Our results do not indicate an increased risk of leukemia from ingestion of natural uranium or other radionuclides through drinking water at these exposure levels.
authors.affiliation: STUK--Radiation and Nuclear Safety Authority, Research and Environmental Surveillance, Helsinki, Finland. anssi.auvinen@uta.fi
authors.forename: Anssi
authors.initials: A
authors.lastname: Auvinen
authors.forename: Päivi
authors.initials: P
authors.lastname: Kurttio
authors.forename: Juha
authors.initials: J
authors.lastname: Pekkanen
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
authors.forename: Taina
authors.initials: T
authors.lastname: Ilus
authors.forename: Laina
authors.initials: L
authors.lastname: Salonen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D016001:Confidence Intervals; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007938:Leukemia / Q000453:epidemiology*; D008297:Male; D016016:Proportional Hazards Models; D011883:Radium / Q000032:analysis; D011886:Radon / Q000032:analysis; D012016:Reference Values; D012307:Risk Factors; D014501:Uranium / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
chemical_list: D014875:Water Pollutants, Radioactive; D014501:Uranium; D011886:Radon; D011883:Radium