ISO 11665 discusses the measurement of radioactivity in the environment. Since radon present in soil can leech into the environment, it can pose a health risk to occupants of buildings where it has entered indoor air. It is important to measure the quantity of radon in this air to determine whether the occupants are safe.
ISO 11665‑5 is the fifth part of the multi-series on measurement of radioactivity in the environment that describes continuous measurement methods for radon-222. ISO 11665 gives indications for continuous measuring of the temporal variations of radon activity concentration in open or confined atmospheres.
ISO 11665‑5 is for assessing temporal changes in radon activity concentration in the environment, in public buildings, in homes, and in workplaces; as a function of influence quantities such as ventilation and/or meteorological conditions. The measurement method described applies to air samples with radon activity concentration is greater than 5 Bq/m3.
ISO 11665‑5 on measurement of radioactivity in the environment is useful for:
Radon present in soil enters buildings via diffusion. Over time, radon concentration in indoor air can increase, posing a health hazard for occupants of the building. Indoor radon activity concentration depends on radon activity concentration in the underlying soil, the building structure, the equipment (chimney, ventilation systems, among others), the environmental parameters of the building (temperature, pressure, etc.) and the occupants’ lifestyle.
To limit the risk to individuals, a national reference level of 100 Bq.m-3 is recommended by the World Health Organization. ISO 11665‑5 deals with continuous measurement methods for radon-222.
ISO 11665‑5 provides a continuous measurement method to reduce the risk to the overall population. Building codes should be implemented that require radon prevention measures in buildings under construction and radon mitigating measures in existing buildings. Radon measurements are needed because building codes alone cannot guarantee that radon concentrations are below the reference level.
BS EN ISO 11665‑5:2020 supersedes EN ISO 11665‑5:2015.
The main changes compared to the previous version are as follows:
ISO 11665-5
EN ISO 11665-5