Starting from a pilot study carried out in 438 schools located in Puglia, a region in South Italy... more Starting from a pilot study carried out in 438 schools located in Puglia, a region in South Italy, a plan of mitigation actions has been designed and realized in building in which the Italian national radon action level (500 Bq/m3 as annual average radon concentration) was exceeded. Data analysis showed that 7% of schools needed of remedial actions which were supported by a unique measurement protocol. The measurement protocol consists of time integrated monitoring by SSNTD and electrets (EIC) dosimeters and active measurements by ionization chambers. The remedial actions, carried out in twelve schools, identified according to the building characteristics and radon average levels, resulted in an effectiveness between 65 - 85%. Particular attention has been paid to the managing procedure of suction systems in order to reduce the overheads. The different mitigation plans have been discussed with local administrations and take into account both stringent structural requirements and eas...
Il monitoraggio di 438 edifici scolastici della Provincia di Lecce, effettuato nell’ambito di una... more Il monitoraggio di 438 edifici scolastici della Provincia di Lecce, effettuato nell’ambito di una campagna di misure tra il 2005/2006, ha evidenziato una concentrazione media di radon pari a 209±9 Bq/m3, valore di gran lunga superiore a quella stimata per la Puglia 52±2 Bq/m3. L’analisi dei dati ha mostrato che il 7% delle scuole necessitava di azioni di bonifica e a tal fine è stato predisposto un dettagliato protocollo di intervento sottoponendo a bonifica inizialmente sedici edifici scolastici. La totalità degli interventi realizzati ha riguardato prevalentemente la depressurizzazione del suolo o del vespaio mediante sistemi di aspirazione con tubazioni in verticale e/o orizzontale. Nella maggior parte dei casi si sono ottenute buone percentuali di abbattimento tuttavia comprese tra 20 - 90%, attestate con misure di monitoraggio annuo
h i g h l i g h t s Natural radionuclides content in building materials added with NORM. Radon ex... more h i g h l i g h t s Natural radionuclides content in building materials added with NORM. Radon exhalation in concrete added with NORM. Intercomparison of radon exhalation rate results. Effect of the concrete microstructure on radon exhalation rate.
Journal of radiological protection : official journal of the Society for Radiological Protection, Jan 24, 2017
The final results of radon monitoring in 438 schools located in the province of Lecce (Puglia Reg... more The final results of radon monitoring in 438 schools located in the province of Lecce (Puglia Region, South Italy) showed an average radon concentration of 215 ± 20 Bq m(-3) and that 7% of schools exceeded 500 Bq m(-3), the current Italian action level for radon in workplaces, and consequently required remedial actions. The activity described in the present paper includes the main elements of the remediation project in a subgroup of school buildings. The main radon control systems adopted were sub-slab depressurization (in 57% of schools) and the active ventilation of the crawlspace (in 21% of schools). This experience allows us to put in evidence relevant critical aspects, such as the influence of the karstic nature of the area, the optimization of remediation, the architectural constraints in the case of buildings of architectural or historical interest, which are discussion herein. Moreover, considering the new reference level for radon in workplaces introduced by the new EU Basi...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2010
Etched track detectors are widely used for the detection of radon and its decay products. The rel... more Etched track detectors are widely used for the detection of radon and its decay products. The reliability of radon measurement performed with such devices requires that laboratories producing analytical data are able to provide results of the required quality. The need for uniform results from laboratories at an international level therefore requires the implementation of a quality assurance programme, the harmonization of criteria, sampling procedures, calculations and the reporting of results, agreed on the basis of fundamental principles and international standards. The quality assurance programme described here is the first step on the way to ISO/IEC 17025 certification for the RI-RN (ISPESL) laboratory.
An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etch... more An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etching in 5.4 N KOH solution at 80 C is carried out in the present work. The response of PADC samples has been evaluated adopting the fission fragment track diameter method. A standard quality control program for etching has been set up by monitoring the electrical conductivity of the etchant. Since the properties of the etching solution are constant during the etching process the difference in the Vb values are connected to the intrinsic characteristics of the CR-39 plastic such as polymerization processes.
A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educatio... more A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educational buildings (506 schools) located in South-East Italy (the Salento peninsula, province of Lecce). In this paper the final findings relating to measurements performed with SSNTD dosemeters in 438 schools (86% of the sample) are reported. The average annual activity concentration of radon in schools located in the province of Lecce is 209 ± 9 Bq/m(3). Radon values actually ranged from 21 Bq/m(3) to 1608 Bq/m(3). About 7% of schools showed radon concentration values above 500 Bq/m(3), the Italian action level for workplaces.
In the framework of a collaboration between INAIL and University of Salento, an indoor radon surv... more In the framework of a collaboration between INAIL and University of Salento, an indoor radon survey in 54 buildings belonging to the UniSalento University (Southeast Italy) was carried out. The monitored buildings differ by type, construction period, materials, etc., and are located in an area with a morphology characterized mainly by marls, calcareous marls, and calcarenites (karst area). The sample of the survey includes 963 rooms at different floors: it consists in rooms mainly located at ground floor (67%), first floor (12%), and below ground (12%). SSNTD passive dosimeters measured the average radon activity concentration for two consecutive semesters (spring/summer and autumn/winter) from which annual radon averages were estimated for each room. The spatial variability within buildings was investigated in terms of variation between floors and among rooms at the same floor. Data analysis provides evidence that the distributions (in terms of arithmetic mean, standard deviation, ...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2010
Etched track detectors are widely used for the detection of radon and its decay products. The rel... more Etched track detectors are widely used for the detection of radon and its decay products. The reliability of radon measurement performed with such devices requires that laboratories producing analytical data are able to provide results of the required quality. The need for uniform results from laboratories at an international level therefore requires the implementation of a quality assurance programme, the harmonization of criteria, sampling procedures, calculations and the reporting of results, agreed on the basis of fundamental principles and international standards. The quality assurance programme described here is the first step on the way to ISO/IEC 17025 certification for the RI-RN (ISPESL) laboratory.
The background of CR-39 detectors varies from batch to batch, from foil to foil in the same batch... more The background of CR-39 detectors varies from batch to batch, from foil to foil in the same batch, from one side to another of the same foil and within the same foil surface. In spite of many efforts made in the past, little success has been achieved in producing detectors with a consistently low background. For this reason, new investigations have been undertaken with the specific scope in mind to improve the background of these detectors. The key strategy of these studies was to investigate whether the background tracks originate from the detector surface or from detector bulk, if not from both. From these systematic investigations it was possible to demonstrate that most of the background is due to defects present on the detector surface. For this reason, the simplest way to reduce the background is to carry out a heavy pre-etching prior to the use of the CR-39 detector. This procedure has been successfully exploited not only to increase the signal-to-noise ratio of CR-39-based radon dosimeters but also to carry out different radon measurements with the same CR-39 foil.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
In the period 2005-2006 a survey on natural radioactivity in about 500 schools located in south-e... more In the period 2005-2006 a survey on natural radioactivity in about 500 schools located in south-east Italy (the Salento peninsula, province of Lecce) was carried out. In particular average radon concentration and average absorbed dose rate in air due to gamma radiation have been assessed by using solid state nuclear track detectors (SSNTD) and electret ionization chambers (EIC), as well as thermoluminescence dosimeters (TLD), respectively. SSNTD dosimeters were placed in every school, while electrets and TLD have been employed in a pilot study performed in a selected sample of 56 schools in order to achieve preliminary information. Moreover the study foresaw a quality control on electret dosimeters' perfomances in terms of homogeneity and reliability. The results of this check have been taken into account in the data analysis. In this paper final results concerning the pilot study are reported. The indoor radon levels measured in the schools ranged from 65 Bq/m 3 to 1808 Bq/m 3 , and only six schools (corresponding to 13% of the sample) showed radon annual average above 500 Bq/m 3 , Italian action level for workplaces. For the average absorbed dose rate in air due to gamma radiation, the recorded values ranged between 47 and 83 nGy/h with an average value of 61 nGy/h.
An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etch... more An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etching in 5.4 N KOH solution at 80 C is carried out in the present work. The response of PADC samples has been evaluated adopting the fission fragment track diameter method. A standard quality control program for etching has been set up by monitoring the electrical conductivity of the etchant. Since the properties of the etching solution are constant during the etching process the difference in the Vb values are connected to the intrinsic characteristics of the CR-39 plastic such as polymerization processes.
Starting from a pilot study carried out in 438 schools located in Puglia, a region in South Italy... more Starting from a pilot study carried out in 438 schools located in Puglia, a region in South Italy, a plan of mitigation actions has been designed and realized in building in which the Italian national radon action level (500 Bq/m3 as annual average radon concentration) was exceeded. Data analysis showed that 7% of schools needed of remedial actions which were supported by a unique measurement protocol. The measurement protocol consists of time integrated monitoring by SSNTD and electrets (EIC) dosimeters and active measurements by ionization chambers. The remedial actions, carried out in twelve schools, identified according to the building characteristics and radon average levels, resulted in an effectiveness between 65 - 85%. Particular attention has been paid to the managing procedure of suction systems in order to reduce the overheads. The different mitigation plans have been discussed with local administrations and take into account both stringent structural requirements and eas...
Il monitoraggio di 438 edifici scolastici della Provincia di Lecce, effettuato nell’ambito di una... more Il monitoraggio di 438 edifici scolastici della Provincia di Lecce, effettuato nell’ambito di una campagna di misure tra il 2005/2006, ha evidenziato una concentrazione media di radon pari a 209±9 Bq/m3, valore di gran lunga superiore a quella stimata per la Puglia 52±2 Bq/m3. L’analisi dei dati ha mostrato che il 7% delle scuole necessitava di azioni di bonifica e a tal fine è stato predisposto un dettagliato protocollo di intervento sottoponendo a bonifica inizialmente sedici edifici scolastici. La totalità degli interventi realizzati ha riguardato prevalentemente la depressurizzazione del suolo o del vespaio mediante sistemi di aspirazione con tubazioni in verticale e/o orizzontale. Nella maggior parte dei casi si sono ottenute buone percentuali di abbattimento tuttavia comprese tra 20 - 90%, attestate con misure di monitoraggio annuo
h i g h l i g h t s Natural radionuclides content in building materials added with NORM. Radon ex... more h i g h l i g h t s Natural radionuclides content in building materials added with NORM. Radon exhalation in concrete added with NORM. Intercomparison of radon exhalation rate results. Effect of the concrete microstructure on radon exhalation rate.
Journal of radiological protection : official journal of the Society for Radiological Protection, Jan 24, 2017
The final results of radon monitoring in 438 schools located in the province of Lecce (Puglia Reg... more The final results of radon monitoring in 438 schools located in the province of Lecce (Puglia Region, South Italy) showed an average radon concentration of 215 ± 20 Bq m(-3) and that 7% of schools exceeded 500 Bq m(-3), the current Italian action level for radon in workplaces, and consequently required remedial actions. The activity described in the present paper includes the main elements of the remediation project in a subgroup of school buildings. The main radon control systems adopted were sub-slab depressurization (in 57% of schools) and the active ventilation of the crawlspace (in 21% of schools). This experience allows us to put in evidence relevant critical aspects, such as the influence of the karstic nature of the area, the optimization of remediation, the architectural constraints in the case of buildings of architectural or historical interest, which are discussion herein. Moreover, considering the new reference level for radon in workplaces introduced by the new EU Basi...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2010
Etched track detectors are widely used for the detection of radon and its decay products. The rel... more Etched track detectors are widely used for the detection of radon and its decay products. The reliability of radon measurement performed with such devices requires that laboratories producing analytical data are able to provide results of the required quality. The need for uniform results from laboratories at an international level therefore requires the implementation of a quality assurance programme, the harmonization of criteria, sampling procedures, calculations and the reporting of results, agreed on the basis of fundamental principles and international standards. The quality assurance programme described here is the first step on the way to ISO/IEC 17025 certification for the RI-RN (ISPESL) laboratory.
An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etch... more An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etching in 5.4 N KOH solution at 80 C is carried out in the present work. The response of PADC samples has been evaluated adopting the fission fragment track diameter method. A standard quality control program for etching has been set up by monitoring the electrical conductivity of the etchant. Since the properties of the etching solution are constant during the etching process the difference in the Vb values are connected to the intrinsic characteristics of the CR-39 plastic such as polymerization processes.
A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educatio... more A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educational buildings (506 schools) located in South-East Italy (the Salento peninsula, province of Lecce). In this paper the final findings relating to measurements performed with SSNTD dosemeters in 438 schools (86% of the sample) are reported. The average annual activity concentration of radon in schools located in the province of Lecce is 209 ± 9 Bq/m(3). Radon values actually ranged from 21 Bq/m(3) to 1608 Bq/m(3). About 7% of schools showed radon concentration values above 500 Bq/m(3), the Italian action level for workplaces.
In the framework of a collaboration between INAIL and University of Salento, an indoor radon surv... more In the framework of a collaboration between INAIL and University of Salento, an indoor radon survey in 54 buildings belonging to the UniSalento University (Southeast Italy) was carried out. The monitored buildings differ by type, construction period, materials, etc., and are located in an area with a morphology characterized mainly by marls, calcareous marls, and calcarenites (karst area). The sample of the survey includes 963 rooms at different floors: it consists in rooms mainly located at ground floor (67%), first floor (12%), and below ground (12%). SSNTD passive dosimeters measured the average radon activity concentration for two consecutive semesters (spring/summer and autumn/winter) from which annual radon averages were estimated for each room. The spatial variability within buildings was investigated in terms of variation between floors and among rooms at the same floor. Data analysis provides evidence that the distributions (in terms of arithmetic mean, standard deviation, ...
Journal of radiological protection : official journal of the Society for Radiological Protection, 2010
Etched track detectors are widely used for the detection of radon and its decay products. The rel... more Etched track detectors are widely used for the detection of radon and its decay products. The reliability of radon measurement performed with such devices requires that laboratories producing analytical data are able to provide results of the required quality. The need for uniform results from laboratories at an international level therefore requires the implementation of a quality assurance programme, the harmonization of criteria, sampling procedures, calculations and the reporting of results, agreed on the basis of fundamental principles and international standards. The quality assurance programme described here is the first step on the way to ISO/IEC 17025 certification for the RI-RN (ISPESL) laboratory.
The background of CR-39 detectors varies from batch to batch, from foil to foil in the same batch... more The background of CR-39 detectors varies from batch to batch, from foil to foil in the same batch, from one side to another of the same foil and within the same foil surface. In spite of many efforts made in the past, little success has been achieved in producing detectors with a consistently low background. For this reason, new investigations have been undertaken with the specific scope in mind to improve the background of these detectors. The key strategy of these studies was to investigate whether the background tracks originate from the detector surface or from detector bulk, if not from both. From these systematic investigations it was possible to demonstrate that most of the background is due to defects present on the detector surface. For this reason, the simplest way to reduce the background is to carry out a heavy pre-etching prior to the use of the CR-39 detector. This procedure has been successfully exploited not only to increase the signal-to-noise ratio of CR-39-based radon dosimeters but also to carry out different radon measurements with the same CR-39 foil.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
In the period 2005-2006 a survey on natural radioactivity in about 500 schools located in south-e... more In the period 2005-2006 a survey on natural radioactivity in about 500 schools located in south-east Italy (the Salento peninsula, province of Lecce) was carried out. In particular average radon concentration and average absorbed dose rate in air due to gamma radiation have been assessed by using solid state nuclear track detectors (SSNTD) and electret ionization chambers (EIC), as well as thermoluminescence dosimeters (TLD), respectively. SSNTD dosimeters were placed in every school, while electrets and TLD have been employed in a pilot study performed in a selected sample of 56 schools in order to achieve preliminary information. Moreover the study foresaw a quality control on electret dosimeters' perfomances in terms of homogeneity and reliability. The results of this check have been taken into account in the data analysis. In this paper final results concerning the pilot study are reported. The indoor radon levels measured in the schools ranged from 65 Bq/m 3 to 1808 Bq/m 3 , and only six schools (corresponding to 13% of the sample) showed radon annual average above 500 Bq/m 3 , Italian action level for workplaces. For the average absorbed dose rate in air due to gamma radiation, the recorded values ranged between 47 and 83 nGy/h with an average value of 61 nGy/h.
An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etch... more An analysis concerning the bulk etch rate of different type of CR-39 subjected to a chemical etching in 5.4 N KOH solution at 80 C is carried out in the present work. The response of PADC samples has been evaluated adopting the fission fragment track diameter method. A standard quality control program for etching has been set up by monitoring the electrical conductivity of the etchant. Since the properties of the etching solution are constant during the etching process the difference in the Vb values are connected to the intrinsic characteristics of the CR-39 plastic such as polymerization processes.
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Papers by Sabrina Tonnarini