DIN ISO 11665-1:2013-05

Radon is today considered to be the main source of human exposure to natural radiation. The UNSCEAR (2006) report suggests that, at the worldwide level, radon accounts for around 52 % of global average exposure to natural radiation. The radiological impact of isotope 222 (48 %) is far more significant than isotope 220 (4 %), while isotope 219 is considered negligible. Exposure to radon and its decay products varies tremendously from one area to another. It depends firstly on the amount of radon emitted by the soil and, secondly, on the degree of containment and weather conditions in the areas where exposure takes place. When disintegrating, radon emits alpha particles and generates solid decay products, which are also radioactive (polonium, bismuth, lead, etcetera). The potential effects on human health of radon lie primarily in its decay products. Whether or not they are attached to atmospheric aerosols, radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size. This part of the DIN ISO 11665 standard series outlines guidance for measuring ²²²Rn activity concentration and the potential alpha energy concentration of short-lived decay products of ²²²Rn in the air. The responsible committee is GUK 967.2 "Aktivitätsmessgeräte für den Strahlenschutz" ("Activity measuring instruments for radiation protection") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE, Joint Committee with the Radiology Standards Committee (NAR).