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[en] School may be the second largest contributor to radon exposure of students, teachers and stuff,. About 500 measurements have been started in 20 schools located in Campania. Preliminary results showed that higher radon concentrations are in the scientific laboratory. (authors)
[en] R.A.M.O.N.A. (radon monitoring and acquisition) is a compact system for radon and climatic parameters monitoring. The instrument can perform alpha particles spectrometry with a resolution better than .5 %, so it is possible the discrimination of radon and thoron daughters. The development of battery operated electronics with integrated amplifier and micro controller makes the device applicable for in-lab and in-field measurements. Moreover, an ethernet interface allows to remotely drive the system and the download of acquired data. After a wide use of the prototype in laboratory, a lot of systems has been built and installed in some sites to carry out radon monitoring in soil. (authors)
[en] Protection from radon exposure in workplaces and dwellings, as included in the latest relevant international regulations and recommendations, is based on the new concept of 'reference level' whose meaning is significantly different from that of previous 'action level' concept. In fact, whereas remedial actions had to be considered only for radon concentrations above the action level, actions to optimise radon exposure are requested with priority above reference level but optimisation should be applied also for radon concentrations below reference level. Similar considerations can be applied to the usually called 'Rn-prone' areas, which are here proposed to be regulated as 'priority' areas. The main implication of these new challenging concepts is a substantial increase of avertable lung cancer deaths, as it will be shown using Italian data. Some practical examples of possible policy actions fitting an approach based on these new concepts will also be given, which could be useful for the implementation of the Council Directive 2013/59/Euratom. (authors)
[en] Highlights: • Outdoor radon levels can cause departure from lognormal indoor radon distribution. • An analytical method is proposed to evaluate and correct outdoor impact for every radon distribution. • Results of this study can be useful for a correct classification of radon areas. - Abstract: Outdoor radon concentration contributes to indoor radon levels, generally causing a shift from lognormal distribution of measured radon concentration data distribution, and it makes more challenging the estimation of radon distribution parameters on the basis of the lognormal assumption. In particular, lognormal assumption with no correction could lead to a significantly biased estimate of the percentage of dwellings exceeding a certain level, e.g. a reference level (RL), since this is based on biased estimates of geometric mean (GM) and geometric standard deviation (GSD) of radon concentration distribution. Subtracting to each measured data a constant outdoor radon level can usually compensate data distribution departure from log-normality (except for low radon levels), if the appropriate outdoor level value is chosen by means of a lognormal fit of the data. This approach – already (but not always) used in literature – cannot be applied in cases where all the data of radon concentrations are not available (e.g., for a review study). For these cases, this work presents an analytical method to quantitatively evaluate and correct the impact of outdoor on the lognormal distribution parameter estimates and, in particular, on the percentages of dwellings exceeding radon reference levels. The proposed method is applied to a number of possible situations, with different values of outdoor radon level, GM and GSD. The results show that outdoor radon levels generally produce an underestimation of the actual GSD parameter, which increases as the outdoor level increases, and in the worse cases, could lead to an underestimation higher than 50%. Consequently, if the outdoor contribution is not properly taken into account, the percentage of dwellings exceeding a certain RL is almost always underestimated, even by 80%–90% for RL equal to 300 Bq/m3. This could have implications for the classification of areas as regards radon concentration and for the estimation of avertable lung cancers attributable to radon levels higher than some possible RLs.
[en] Many international and national regulations on radon in workplaces, including the 2013/59/Euratom Council Directive, are based on the annual average of indoor radon concentration, assuming it is representative of the long-term average. However, a single annual radon concentration measurement does not reflect annual variations (i.e. year-to-year variations) of radon concentration in the same location. These variations, if not negligible, should be considered for an optimized implementation of regulations. Unfortunately, studies on annual variations in workplaces can be difficult and time-consuming and no data have been published on scientific journals on this issue. Therefore, we carried out a study to obtain a first evaluation of short-term annual variations in workplaces of a research institute in Rome (Italy). The radon concentration was measured in 120 rooms (mainly offices and laboratories) located in 23 buildings. In each room, two 1-year long measurements were performed, with an interval between the two measurements of up to 3 years. The results show variability between the two 1-year long measurements higher than the variability observed in a sample of dwellings in the same area. Further studies are required to confirm the results and to extend the study to other types of workplaces. (authors)
[en] Environmental topics are today at the centre of the public attention, but people mostly does not have cultural tools for an adequate knowledge. The radioactivity, in particular, is generally misunderstood and this had negatively influence debate about the energy. To fill this gap science subjects need to be study in school with a more efficient approach. Many efforts have spent to obtain this goal: in this framework the Envirad project was developed with the aim to make students of high schools of Campania Region (south-Italy) able to practice experimental method involving directly them in a real environmental physics experiment . The aim of this project, developed by the grant of the Istituto Nazionale di Fisica Nucleare, is that the effective experimental activity is the best way to provide for an adequate scientific background. (N.C.)
[en] Measurements covering a 1 year period are often used and required by legislation to assess the average radon concentration within a house or a workplace. This kind of long-term measurement—generally carried out with techniques based on nuclear track detectors—can be affected by a reduction in sensitivity due to ageing and fading of latent tracks during the exposure period, thus resulting in an underestimation of the actual average concentration. In order to evaluate in field conditions the ageing and fading effects on annual radon concentration measurements, two different studies in a large sample of rooms in dwellings (162) and in workplaces (432) were conducted using two different techniques (detector and track read-out system): (i) CR-39 plastics readout with a fully automated image analysis system, and (ii) LR 115 films with a spark-counter for track counting. Study design and data analysis aimed to evaluate both the average and the variability of ageing and fading effects in real conditions, and to reduce and separate the contribution of measurement uncertainty to the observed variability. For the CR-39 based technique, the results show that radon concentration measurements over a 12month period are on average about 16% lower than those evaluated with measurements of two consecutive 6 month periods, implying the need for a correction factor to avoid measurement bias (i.e. underestimation) due to ageing and fading effects. The observed variability of ageing and fading effects among the sampled rooms is not negligible (coefficient of variation about 18%), although a considerable fraction is attributable to measurement uncertainty, which is presumably not related to ageing and fading. For the technique based on LR 115 spark counting, ageing and fading do not significantly affect the results of radon concentration measurement. (paper)
[en] International recommendations and regulations require developing of National Radon Action Plans (NRAPs) to effectively manage the protection of workers and population from radon exposure. In Italy, a NRAP was published in 2002 and several activities have been carried out in this framework. Information and data regarding these and previous activities have been collected in a National Radon Archive (NRA). Activities carried out by institutionally involved institutes and agencies include several national and regional surveys, involving more than 50 000 indoor environments (dwellings, schools and workplaces), and remedial actions performed in ∼350 buildings, largely in schools. Data collected in the NRA allowed also to estimate that lung cancer deaths attributable to radon exposure in Italy are ∼3400 per year. On-going developments of the Italian NRA finalized to effectively use it as tool for developing, monitoring and updating the NRAP are also described. (authors)
[en] Extensive radon surveys have been carried out in many countries only in dwellings, whereas surveys in workplaces are rather sparse and generally restricted to specific workplaces/activities, e.g. schools, spas and caves. Moreover, radon-prone areas are generally defined on the basis of radon surveys in dwellings, while radon regulations use this concept to introduce specific requirements in workplaces in such areas. This approach does not take into account that work activities and workplace characteristics can significantly affect radon concentration. Therefore, an extensive survey on radon in different workplaces have been carried out in a large region of Italy (Tuscany), in order to evaluate radon distribution in workplaces over the whole territory and to identify activities and workplace characteristics affecting radon concentration. The results of this extensive survey are compared with the results of the survey carried out in dwellings in the same period. The workplaces monitored were randomly selected among the main work activities in the region, including both public and industrial buildings. The survey monitored over 3500 rooms in more than 1200 buildings for two consecutive periods of ∼6 months. Radon concentration was measured by means of passive nuclear track detectors. (authors)
[en] Radon concentration in air is subject to significant variations at different time scales, owing to several factors. In general, the shorter the time period considered, the larger the variations in radon concentration, e.g., day-to-day variations are usually higher than month-to-month variations. An average over 12 consecutive months is generally considered the best estimate of the long-term average radon concentration. Due to practical reasons, however, very few data are available on year-to-year variations. Year-to-year variations can have quite a relevant impact on radon policies and on the assessment of health risks from exposures to radon. Therefore, a project was started in 1996 aimed to evaluate year-to-year variations in a sample of dwellings. Systematic radon measurements have been made with LR 115 based radon detectors (closed type) in the living room and one bedroom of a sample of dwellings in Rome (Italy). The analysis of the results of the first five consecutive years of measurements, regarding the 76 dwellings included in the final analysis, showed relatively low year-to-year variations, with a median coefficient of variation of 14% (range 3%-42%), smaller than that observed in studies from other European countries. Therefore, in the analyzed sample, 12-month measurements can be considered a good estimate of the average radon concentration, at least within a 5-year period. This is quite important for radon regulations and policies, e.g. annual measurements could be recommended and repetition of radon measurements could not be necessary within periods of 5 years. Moreover, the impact of the observed year-to-year variations on the lung cancer risk estimated in the Italian epidemiological study is expected to be not high, if variations on periods up to about 30 years can be assumed similar to those observed in this study.