Radon levels in underground workplaces – results of a nationwide survey in Italy

Radon exposure and its influencing factors across 3,140 workplaces in Spain

Indoor radon exposure increases the risk of lung cancer. Radon concentration in workplaces is regulated in EU countries, including Spain, based on a reference level of 300 Bq/m3. The objective of this study is to describe workplace radon exposure in Spain and its influencing factors. To do this, we collected long-term radon measurements with alpha track detectors in 3140 workplaces mainly located in radon prone areas. Radon concentration exceeded 300 Bq/m3 in 1 out of 5 workplaces. Median radon concentration was 107 Bq/m3 in radon prone areas, 28 Bq/m3 off radon prone areas, and 101 Bq/m3 globally for the complete sample. Our results indicate that excessive radon concentrations can be expected in radon prone areas at all floor levels, especially below ground. Floor level, working sector, and location significantly influence radon concentration. The highest radon concentrations were found in the Education & Culture sector, comprising schools, universities, libraries, or cultural centers. These results indicate that radon should no longer be considered a risk for marginal occupations, but a risk everyone has if located in a radon prone area. Immediate action, including radon testing and mitigation, is needed to protect workers in Spain against radon exposure. This is already mandatory since EU regulation for radon has been recently transposed in Spain. Competent authorities should enforce this regulation without further delay, and employers must address their responsibility and communicate with workers about this risk.

A methodology for the systematic identification of naturally occurring radioactive materials (NORM)

Naturally occurring radioactive materials (NORM) are present worldwide and under certain circumstances (e.g., human activities) may give radiation exposure to workers, local public or occasional visitors and non-human biota (NHB) of the surrounding ecosystems. This may occur during planned or existing exposure situations which, under current radiation protection standards, require identification, management, and regulatory control as for other practices associated with man-made radionuclides that may result in the exposure of people and NHB. However, knowledge gaps exist with respect to the extent of global and European NORM exposure situations and their exposure scenario characteristics, including information on the presence of other physical hazards, such as chemical and biological ones. One of the main reasons for this is the wide variety of industries, practices and situations that may utilise NORM. Additionally, the lack of a comprehensive methodology for identification of NORM exposure situations and the absence of tools to support a systematic characterisation and data collection at identified sites may also lead to a gap in knowledge. Within the EURATOM Horizon 2020 RadoNorm project, a methodology for systematic NORM exposure identification has been developed. The methodology, containing consecutive tiers, comprehensively covers situations where NORM may occur (i.e., minerals and raw materials deposits, industrial activities, industrial products and residues and their applications, waste, legacies), and thus, allows detailed investigation and complete identification of situations where NORM may present a radiation protection concern in a country. Details of the tiered methodology, with practical examples on harmonised data collection using a variety of existing sources of information to establish NORM inventories, are presented in this paper. This methodology is flexible and thus applicable to a diversity of situations. It is intended to be used to make NORM inventory starting from the scratch, however it can be used also to systematise and complete existing data.

Indoor Radon Monitoring in Kindergarten and Primary Schools in South Italy

Humans are mostly exposed to ionizing radiation through radon and its decay products. The results of indoor radon measurements in 39 kindergartens and primary schools in the Campania region of southern Italy are presented in this paper. The survey was carried out with CR-39 solid-state nuclear track detectors (SSNTDs). Radon concentrations were measured and ranged from 11 to 1416 Bq/m3, with a geometric mean of 77 Bq/m3 and a geometric standard deviation of 2. The findings revealed that 70% of the measures were below the WHO recommended level of 100 Bq/m3 and that 97 percent of the measurements were below the 300 Bq/m3 level set by Italian law.

Occupational Radon Assessment in Underground Storage Facilities in Saudi Arabia

ABSTRACT

An occupational radon assessment was conducted at five underground storage facilities in the Kingdom of Saudi Arabia to evaluate the radon concentration and determine if remedial action is required to ameliorate conditions and ensure compliance with international guidance on acceptable radon levels in working environments. The assessment was carried out in four operational areas in the underground storage facilities routinely occupied or visited by workers. Initial radon concentrations were obtained using 293 passive CR-39 Nuclear Track Detector (NTD) radon dosimeters installed in the four operational areas for all the underground storage facilities. The detectors were left in place for 12 mo. As some of the radon measurements exceeded the International Atomic Energy Agency reference level of 1,000 Bq m-3 for radon in workplaces, a follow-up assessment was conducted using a real-time monitoring device in locations where high radon levels were observed. The measured radon concentrations in the four operational areas in three of the five underground storage facilities were below the reference level, and in the remaining two storage facilities, low ventilation rates in one operational area were identified as the principal cause of elevated radon concentrations. Notwithstanding, the potential radiation dose from radon exposure was determined to be well below the International Commission on Radiation Protection reference annual dose level of 10 mSv in all five underground storage facilities. Radon exposure to workers in all the underground storage facilities was found to be within the reference dose level for workplaces and does not pose an acute health risk.

Radon Survey in Bank Buildings of Campania Region According to the Italian Transposition of Euratom 59/2013

222Rn gas represents the major contributor to human health risk from environmental radiological exposure. In confined spaces radon can accumulate to relatively high levels so that mitigation actions are necessary. The Italian legislation on radiation protection has set a reference value for the activity concentration of radon at 300 Bq/m3. In this study, measurements of the annual radon concentration of 62 bank buildings spread throughout the Campania region (Southern Italy) were carried out. Using devices based on CR-39 solid-state nuclear track detectors, the 222Rn level was assessed in 136 confined spaces (127 at underground floors and 9 at ground floors) frequented by workers and/or the public. The survey parameters considered in the analysis of the results were: floor types, wall cladding materials, number of openings, door/window opening duration for air exchange. Radon levels were found to be between 17 and 680 Bq/m3, with an average value of 130 Bq/m3 and a standard deviation of 120 Bq/m3. About 7% of the results gave a radon activity concentration above 300 Bq/m3. The analysis showed that the floor level and air exchange have the most significant influence. This study highlighted the importance of the assessment of indoor radon levels for work environments in particular, to protect the workers and public from radon-induced health effects.

Assessment of occupational exposure from radon in the newly formed underground tourist route under Książ castle, Poland

In the present study, 222Rn activity concentrations in a newly formed underground tourist route under Książ castle, Poland, were investigated for periods undisturbed and disturbed by construction works. This preliminary assessment is based on the almost 3-year long continuous measurements (28 Oct. 2016-02 Jul. 2019) done with an SRDN-3 instrument. In detail described are radon concentrations for periods of renovation (11 Aug. 2018-10 Oct. 2018), opening (15 Oct. 2018-10 Apr. 2019) and operation and monitoring (11 Apr. 2019-02 Jul. 2019) of the facility. It was observed that after the termination of construction work, when natural ventilation returned to the state preceding this work, the absolute values of radon activity concentration decreased. The mean annual radon concentrations were higher than the reference level of radon concentration in underground spaces recommended by IAEA, ICRP, and by the EU Council Directive for workplaces. They reached 1179 Bq/m3 and 943 Bq/m3 in 2017 and 2018, respectively. Cyclically recurring daily changes in radon concentrations occurred only in April and October (so-called transitional periods) and only outside the period of construction work. The results confirmed; however, that these changes need not be considered when planning the work in the tunnel. The minimum effective dose rate from radon exposure occurs in colder periods of the year, from November to the end of March, where the mean effective dose rate value was found to be 0.0003 mSv/h. In contrast, the maximum dose rate of 0.014 mSv/h was observed from April to August.

Indoor Radon Concentration and Risk Assessment in 27 Districts of a Public Healthcare Company in Naples, South Italy

Radon is a major source of ionizing radiation exposure for the general population. It is known that exposure to radon is a risk factor for the onset of lung cancer. In this study, the results of a radon survey conducted in all districts of a Public Healthcare in Italy, are reported. Measurements of indoor radon were performed using nuclear track detectors, CR-39. The entire survey was conducted according to a well-established quality assurance program. The annual effective dose and excess lifetime cancer risk were also calculated. Results show that the radon concentrations varied from 7 ± 1 Bq/m3 and 5148 ± 772 Bq/m3, with a geometric mean of 67 Bq/m3 and geometric standard deviation of 2.5. The annual effective dose to workers was found to be 1.6 mSv/y and comparable with the worldwide average. In Italy, following the transposition of the European Directive 59/2013, great attention was paid to the radon risk in workplaces. The interest of the workers of the monitored sites was very high and this, certainly contributed to the high return rate of the detectors after exposure and therefore, to the presence of few missing data. Although it was not possible to study the factors affecting radon concentrations, certainly the main advantage of this study is that it was the first in which an entire public health company was monitored in regards to all the premises on the underground and ground floor.

Assess the annual effective dose and contribute to risk of lung cancer caused by internal radon 222 in 22 regions of Tehran, Iran using geographic information system

Radon gas is one of the most influential sources of indoor exposure. All its physical properties together make it a significant risk factor for lung cancer in the population. The research aims are outlined as (1) to measure the radon concentration in Tehran city and compare results with the international standards (2) to determine spatial distribution of radon gas concentration using Geographical Information System (GIS) software and (3) to estimate the annual effective dose and potential risk of lung cancer by radon-222 in Tehran city. In this study, 800 Alpha Track detectors were installed in houses in 22 regions of Tehran city and retrieved after 3 months. The measurements were repeated for spring and summer and autumn seasons. The annual effective dose and risk of lung cancer were assessed using standard equations. Data were analyzed using SPSS 20. Result showed the minimum and maximum radon concentration were observed in and Ghalee-kobra (0.13 Bq.m^-3) and Charbagh-ponak district (661.11 Bq.m^-3) respectively. There was no observed relationship between radon concentration and houses' model, cracking condition and constructionn materials. Expectedly, the storehouses and basements had significantly higher (P = 0.016) radon concentration than occupied rooms. The min and max of the estimated annual effective dose were 0.65 and 2.03 mSv, respectively. Result showed that around 5% of the sampling sites had higher level of radon than the maximum allowed by EPA. A rough estimation of the expected radon-attributed lung cancer incidences yielded approximately 5958 cases in the total population of Tehran every year. In view of the growing trend in cancer incidences, appropriate measures addressing radon should be undertaken in areas of increased exposure to this noble gas.

THE NATIONAL RADON ARCHIVE AS A USEFUL TOOL FOR DEVELOPING AND UPDATING THE NATIONAL RADON ACTION PLAN

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.

Radon levels in underground workplaces: a map of the Italian regions

The indoor radon exposition is a widely recognised health hazard, so specific laws and regulations have been produced in many countries and so-called radon-risk maps have consequently been produced. In Italy the regulation applies to general workplaces and a national survey was carried out in the 1990s to evaluate the exposure to radon in dwellings. Failing a national coordinated mapping programme, some Italian regions performed a survey to identify radon-prone areas, nevertheless with different methodologies. In this work a national map of the average annual radon concentration levels in underground workplaces, obtained from the results of 8695 annual indoor radon measurements carried out by U-Series laboratory between 2003 and 2010, was presented. Due to underground locations, the mean radon concentration is higher than that from previous map elaborated for dwellings and a significant radon concentration was also found in Regions traditionally considered as low-risk areas.

Indoor radon concentration measurements in some dwellings of the Penisola Sorrentina, South Italy

In this study, the indoor radon concentrations have been measured in 93 dwellings of the Penisola Sorrentina, using LR115 detectors. The detectors were placed in the bedrooms and living rooms for two consecutive semesters starting from December 2010 to December 2011. The annual average indoor radon concentrations vary from 25 to 722 Bq m(-3), with a mean value of 132 ± 114 Bq m(-3). Correlation between indoor radon measurements and same building characteristics was also studied. Based on the obtained results, the mean annual effective dose of 2.4 mSv y(-1) received by inhabitants was estimated.

Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.