Radon
Rolling revision of the WHO Guidelines for Drinking-water Quality
Radon is included in the plan of work of the rolling revision of the WHO Guidelines for Drinking-water Quality.
Background
Radon may be present in indoor air, as it may enter through the foundation or through the water supply drawn from some groundwaters. It can then be taken up by both ingestion through drinking-water and inhalation of indoor air. The Guidelines for Drinking-water Quality Final Task Force meeting (Geneva, 2003) recommended that the WHO Radiation and Environmental Health Programme prepare guidance on the inhalation of radon from drinking-water sources. The WHO Radiation and Environmental Health Programme has proposed a special project on radon in drinking-water that may impact on the guideline.
Expected end-product(s)
- Additional paragraphs on treatment of radon and mitigation measures, for second addendum;
- Updated guidance in section 9.5 of GDWQ on radon risk assessment and management, for inclusion in Fourth Edition;
- Updated section 9.5 for Fourth Edition
Progress to date
The WHO Radiation and Environmental Health Programme is about to embark on a project in collaboration with the USEPA, Health Canada and others. The Guidelines for Drinking-water Quality Working Group meeting (Geneva, 2004) recommended that the study focus on exposures in developing countries with different indoor inhalation conditions due to less use of showers and more highly ventilated spaces, since most water inhalation calculations have been done under North American-type conditions. No progress had been made on this by the time of the 2005 Guidelines for Drinking-water Quality Working Group meeting. The Guidelines for Drinking-water Quality Working Group meeting (Geneva, 2006) met with representatives of the Radiation and Environmental Health Programme and decided on a path forward for both the second addendum and Fourth Edition.
The draft text is now available for review. Comments are welcome following the format on the comment sheet, below.
Comments on the draft background documents above should be sent before 15 May 2007 to gdwqtreatment@who.int.