The 2013/59/Euratom Council Directive has introduced the new concept of reference level (RL) which will lead the regulatory bodies applying the optimization principle also below it. For indoor radon exposure situations, RL, as well as the previous concept of action level (AL), is expressed in terms of annual average activity concentration of radon in air. This definition assumed that annual average concentration is representative of long-term average – i.e., over periods much longer than one year – considering that radon-related risks were estimated in function of a continuous radon exposure over a period of about 30 years. However, the estimates of this long-term average using a single annual radon concentration measurement could be affected by year-to-year variations (or annual variations) of radon concentrations in the same workplace. These variations, if not negligible, could have an impact on regulations which are based on the comparison between measured annual average concentration and RL. For this reason, in the framework of a survey mainly focused on the evaluation of radon spatial variability in workplaces, we carried out a study aimed to evaluate annual variability. Radon measurements were carried out in 120 rooms located in 23 different buildings of a research institute and repeated after few years (at maximum after 3 years). About 70% of the rooms were located at ground or lower floors. Results show that median CV (coefficient of variation between two measurements in the same room at different years) is 16%, very close to that found for dwellings located in nearby areas. Moreover, for rooms with the first annual average higher than 200 Bq m–3, it was found a median CV slightly higher (21%), and for 80% of these rooms, radon concentrations measured after few years resulted generally lower than the previous ones, with an average reduction of about 30%. In this work, the possible explanations of these results as well as their implications on radon regulations will be discussed.
Annual variations of indoor radon concentration in workplaces / Venoso, G.; Ampollini, M.; Antignani, S.; Caprio, M.; Carpentieri, C.; Di Carlo, C.; Bochicchio, F.. - (2019). (Intervento presentato al convegno 9th International Conference on Protection against Radon at Home and at Work tenutosi a Praga; Repubblica Ceca).
Annual variations of indoor radon concentration in workplaces
Di Carlo C.;
2019
Abstract
The 2013/59/Euratom Council Directive has introduced the new concept of reference level (RL) which will lead the regulatory bodies applying the optimization principle also below it. For indoor radon exposure situations, RL, as well as the previous concept of action level (AL), is expressed in terms of annual average activity concentration of radon in air. This definition assumed that annual average concentration is representative of long-term average – i.e., over periods much longer than one year – considering that radon-related risks were estimated in function of a continuous radon exposure over a period of about 30 years. However, the estimates of this long-term average using a single annual radon concentration measurement could be affected by year-to-year variations (or annual variations) of radon concentrations in the same workplace. These variations, if not negligible, could have an impact on regulations which are based on the comparison between measured annual average concentration and RL. For this reason, in the framework of a survey mainly focused on the evaluation of radon spatial variability in workplaces, we carried out a study aimed to evaluate annual variability. Radon measurements were carried out in 120 rooms located in 23 different buildings of a research institute and repeated after few years (at maximum after 3 years). About 70% of the rooms were located at ground or lower floors. Results show that median CV (coefficient of variation between two measurements in the same room at different years) is 16%, very close to that found for dwellings located in nearby areas. Moreover, for rooms with the first annual average higher than 200 Bq m–3, it was found a median CV slightly higher (21%), and for 80% of these rooms, radon concentrations measured after few years resulted generally lower than the previous ones, with an average reduction of about 30%. In this work, the possible explanations of these results as well as their implications on radon regulations will be discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
