Uranium in drinking-water: a unique case of guideline value increases and discrepancies between chemical and radiochemical guidelines

Environ Int. 2015 Apr:77:1-4. doi: 10.1016/j.envint.2014.12.011. Epub 2015 Jan 14.

Abstract

Background: Uranium represents a unique case for an element naturally present in the environment, as its chemical guideline value in drinking water significantly increased from 2 μg/L in 1998 up to 15 μg/L in 2004 and then to 30 μg/L in 2011, to date corresponding to a multiplication factor of 15 within a period of just 13 years.

Objectives: In this commentary we summarize the evolution of uranium guideline values in drinking-water based on both radiological and chemical aspects, emphasizing the benefit of human studies and their contribution to recent recommendations. We also propose a simpler and better consistency between radiological and chemical values.

Discussion: The current chemical guideline value of 30 μg/L is still designated as provisional because of scientific uncertainties regarding uranium toxicity. During the same period, the radiological guideline for (238)U increased from 4 Bq/L to 10 Bq/L while that for (234)U decreased from 4 Bq/L to 1 Bq/L. These discrepancies are discussed here, and a value of 1 Bq/L for all uranium isotopes is proposed to be more consistent with the current chemical value of 30 μg/L.

Conclusion: Continuous progress in the domains of toxicology and speciation should enable a better interpretation of the biological effects of uranium in correlation with epidemiological human studies. This will certainly aid future proposals for uranium guideline values.

Keywords: Drinking-water; Epidemiology; Guidelines; Toxicity; Uranium.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Drinking Water / chemistry*
  • Drinking Water / standards
  • Environmental Exposure / adverse effects
  • Guidelines as Topic / standards*
  • Humans
  • No-Observed-Adverse-Effect Level
  • Reference Values
  • Time Factors
  • Uranium / analysis
  • Uranium / standards*
  • Uranium / toxicity
  • Water Pollutants, Radioactive / analysis
  • Water Pollutants, Radioactive / standards*
  • Water Pollutants, Radioactive / toxicity
  • World Health Organization

Substances

  • Drinking Water
  • Water Pollutants, Radioactive
  • Uranium