Health Canada has drafted an assessment of uranium in drinking water for public consultation. The document focuses on uranium’s chemical toxicity as opposed to its radiological properties, as it has been determined that it is not present at a high enough concentration in Canadian drinking water to pose any radiation-related danger to the population. The primary health concern from the oral ingestion of natural uranium is kidney toxicity and a tolerable daily intake (TDI) of 0.6 μg/kg bw/day was based on a lowest-observed-adverse-effect level (LOAEL) for kidney lesions of 60 µg uranium/kg bw/day in rats given drinking water containing uranyl nitrate hexahydrate for 91 days. The weight of evidence suggested that assessment factors additional to the standard factor of 100 for inter- and intraspecies differences were not required (e.g. for the use of subchronic data, or for the use of a LOAEL). From the TDI, a maximum acceptable concentration (MAC) of 20 µg/L was proposed. Data from a national survey of Canadian drinking water in 2015 found an average level of 0.52 µg/L, with a range of <0.1-32 µg/L, indicating a possible health concern in some areas.

Health Canada (2017). Federal-Provincial-Territorial Committee on Drinking Water. Document for public consultation. Uranium in drinking water. https://www.canada.ca/content/dam/hc-sc/documents/programs/consultation-uranium-drinking-water/consultation-uranium-drinking-water-eng.pdf

 

The above items were taken from the December 2017 issue of Toxicology and Regulatory News which is sent automatically to members of bibra.

News Home Guest Write For Us? Contact Us