Roselyne Ameon, project leader of the series of standards comments: “By proposing standardized measurement methods for testing laboratories, the ISO 11665 series of standards will help to reduce health risks due to exposure to radon i in taking measures for preventing and mitigating radon effect. Radon measurements in homes are easy to perform, but need to be based on standardized protocols to ensure accurate and consistent measurements. Quality assurance and quality control measures are strongly recommended to assure the reliability of radon test results."

“Radon is a chemically inert, naturally occurring radioactive gas. It has no smell, colour or taste. Radon is produced from the natural radioactive decay of uranium, which is found in rocks and soil. Radon escapes from the ground into the air, where it disintegrates through short-lived decay products called radon progeny. As radon progeny decay, they emit radioactive alpha particles and attach to aerosols, dust and other particles in the air. As we breathe, radon progeny are deposited on the respiratory tract and can cause cancers.”

The ISO 11665 series of standards provides several testing methods. Selection of the appropriate method will depend on the intended use of the data and the site under investigation, such as underground mines, outdoors, houses, buildings open to the public, workplaces, etc.

ISO 11665 consists of the following parts, under the general title; Measurement of radioactivity in the environment - Air: radon-222:

• Part 1: Origins of radon and its short-lived decay products and associated measurement methods
• Part 2: Integrated measurement method for determining average potential alpha energy concentration of its short-lived decay products
• Part 3: Spot measurement method of the potential alpha energy concentration of its short-lived decay products
• Part 4: Integrated measurement method for determining average activity concentration using passive sampling and delayed analysis
• Part 5: Continuous measurement method of the activity concentration
• Part 6: Spot measurement method of the activity concentration
• Part 7: Accumulation method for estimating surface exhalation rate
• Part 8: Methodologies for initial and additional investigations in buildings

The following parts are in preparation:

• Part 9: Method for determining exhalation rate of dense building materials
• Part 10: Determination of diffusion coefficient in waterproof materials using activity concentration measurement
• Part 11: Test method for soil gaz.

The measurement results will notably help to ensure compliance with the WHO recommendations on the reduction of indoor radon concentrations; “WHO recommends that countries implement national programmes to reduce the population’s risk from exposure to the national average radon concentration, as well as reducing the risk for individuals exposed to high radon levels. Building codes should be implemented to reduce radon levels in homes under construction.”

ISO 11665-1 to ISO 11665-8 were prepared by ISO technical committee ISO/TC 85, Nuclear energy, nuclear technologies, and radiological protection, subcommittee SC 2, Radiological protection. They are available from ISO national member institutes (see the complete list with contact details). They may also be obtained directly from ISO Central Secretariat, respective prices 128, 80, 98, 122, 80, 80, 108 and 98 Swiss francs, through the ISO Store or by contacting the Marketing, Communication & Information department.