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MEASUREMENTS OF INDOOR RADON CONCENTRATION IN ITALIAN RED CROSS WORKPLACES: PRELIMINARY RESULTS

C.Fontana*, R.G. Musumeci*, S.Tonnarini+, R.Trevisi+, F.Valeriani*

(*)Laboratory of Environmental Radioactivity -Department of Health, Italian Red Cross Via B.Ramazzini,15 - 00151 (+)Department of Occupational Hygiene – Italian National Institute for Occupational Prevention and Safety (ISPESL), Via Fontana Candida, 1 – 00040 Monteporzio Catone (RM)

INTRODUCTION In August 2000 in the D.Lgs.241/00 law was passed to implement the 96/29 Euratom Directive (BSS Directive, EC 1996). D.Lgs.241/00 states that workers cannot be exposed to decay products of radon, thoron and gamma radiation at a level higher than action level. (1) (2) The law became effective January 1, 2001. Italian action level of 500 Bq/m3 is the annual average indoor radon concentration. Work activities in zones with greater probability of high indoor radon concentration have to be identified. According to the law, a Commission must establish criteria for clarifying areas at risk. The actual work of classification is then done by the regions. A three year time period was given to define areas at risk. As the normative still must be completed, the Italian Red Cross and the Italian National Institute for Occupational Prevention and Safety initiated this study both because the Red Cross has always been sensitive to health problems and also to offer the Commission further experimental data regarding radon in Italy.(3) (4) Results of the national study of natural radiation in homes

A representative national survey to estimate the exposure of the population to radon in dwellings was conducted from 1989 to 1994 by the Italian National Institute of Health and the National Agency for the Protection of the Environment. (5) (6) The average value of indoor annual radon concentration was 75 Bq/m3 and the average values in Italian Regions falls within 20 - 120 Bq/m3 range: note that Italy is divided into 19 districts called Regions and 2 administratively independent Provinces. The results of the 17 Regions and 2 Provinces that participated in the national survey, (the two southernmost Regions didn’t participate) are described in Table 1. Table 1 Average 222Rn concentration range in Italy (Bq/m3) Number of Names of Regions Average radon Regions concentration range 222Rn (Bq/m3) 3 , , 20 – 40 8 , Puglia, Valle d’, , Trentino, 40 – 60 Emilia Romagna, Toscana, 4 Piemonte, Province Autonome di e 60 – 80 Bolzano, , Sardegna 2 , 80 – 100 2 Lombardia, 100 – 120

Description of the Italian Red Cross The Italian Red Cross is composed of central and peripheral structures as designated by a recent normative. The Central Committee is in Rome, and there are Regional, Provincial and Local Committees. 557 Red Cross centers are located in Italy: 19 Regional Committees, 101 Provincial Committees and 437 Local Committees. The Red Cross has both paid workers and 6 Volunteer Organizations. 3,000 people are paid and 150,000 are volunteers.

Scope of the Study Using the data in Table 2, the Laboratory of Environmental Radioactivity of the Department of Health of the Italian Red Cross (SMRA/SAS - CRI) (7) and the Laboratory of Ionizing Radiation of the Department of Occupational Hygiene of the Italian National Institute for Occupational Prevention and Safety (Lab. RINI - ISPESL) planned to monitor the indoor radon concentration in Italian Red Cross workplaces. Because there are many sites in each district of the Italian Red Cross, the first step was to choose a particular town in each district for study. Districts that in the national survey presented a higher average indoor radon concentration range (see Table 1), in particular Lazio, Lomdardia, Campania and Friuli Venezia Giulia Table 2 were favoured. Within these districts a city or small town was chosen in which the radon risk would have been more significant according to available data from literature and/or the results of a questionnaire sent to each CRI’s office in that city and other questionnaires will follow. Table 2 Italian Red Cross Centers chosen for the radon screening Regions ( Regional, Provincial and Local Committees) ABRUZZO – – L’Aquila BASILICATA CAMPANIA** Napoli – Pozzuoli - Caserta FIULI V.G.** Udine – La Tisana LAZIO** Viterbo – Tarquinia - Roma LIGURIA Savona – Tirano – La Spezia LOMBARDIA** Monza TOSCANA Pistoia – Monsummano Terme - Quarrata UMBRIA Gubbio - Orvieto VENETO Rovigo ** Regions that presented higher than average indoor radon concentration range (1)

MATERIALS AND METHODS Indoor radon passive measurements Radon concentration measurements were carried out by Solid State Nuclear Track Detectors (SSNTDs); in particular, the NRPB/SSI type radon monitors. This passive radon monitor consists of a diffusion chamber made of conductive plastic less than 2-cm tall, containing a CR-39 film (Columbia Resin 1939) as track detector. (8) (9) The NRPB/SSI type radon monitors were exposed for a period of about three months (April- July). After the exposure the CR-39 detectors were chemically etched with a 30% KOH solution at 80° C for 5.5 hours, washed in distilled water and dried. Given these etching conditions, a low power microscope with magnification of x 50 was used for the automatic counting . The average radon concentration was calculated by :

CRn = G – B S x T

3 Where CRn is the radon concentration (Bq/m ), G and B are the gross and the background tracks densities (tracks cm-2), S is the calibration factor (tracks cm-2 Bq-1 m3 h-1) and T is the exposure time (h). Detectors calibration was done at the National Radiation Protection Board (UK) and the value obtained for the detector calibration factor was tracks  m 3 S  2,8 M 0,2 cm 2  kBq  h

Indoor radon active measurements Short time radon measurements were taken in some Italian Red Cross sites for screening purposes, and in particular, preliminary radon active measurements were taken to estimate the necessity of reducing the exposure time of radon passive monitors. An Alphaguard 2000 Pro (Genitron) was used and an ionizing chamber in diffusion “mode”. The sampling was done on an average for three hours with integration every ten minutes and with simultaneous recording of the main microclimatic parameters (humidity and temperature).

RESULTS AND DISCUSSION Two regions were monitored in the spring of 2002: Lazio and Campania. Lombardia is still being studied. Three places were individuated in each region: Caserta, Pozzuoli and (Campania region) and Viterbo, Tarquinia and Rome (Lazio region) with the agreement of the Regional Presidents of the CRI. Table 3 A questionnaire was prepared to assist the evaluation of the typology of the centers: address of the site, age of the building, construction materials used, floor, number of rooms, and personnel by floor and room. The floor plans of the sites were given to facilitate measurement. The dosimeters were positioned by specialized personnel from both the Red Cross and Ispesl with the permission of the Directors of the centers. The lowest floors were chosen for the study as they are the areas most at risk.

Table 3 Italian Red Cross Sites – 1st measurement campaign (April-July 2002)

Locality Age of the Place of Floor Region (CRI site) Building g Measurement 1800 Place 1 Ground Floor Campania Caserta (CE) Place 2 Ground Floor (CRI Provincial Committee) Place 3 1st floor Place 4 1st Floor Pozzuoli (NA) 1984 Place 1 Ground Floor Place 2 Ground Floor (CEM–CRI Provincial Committee) Place 3 Ground Floor Place 4 Ground Floor

Napoli 1948 Place 1 6 th Floor (CRI Regional Committee) Place 2 6 th Floor Place 1 Ground Floor Viterbo Lazio 1998 Place 2 Ground Floor (CRI Provincial Committee) Place 3 Ground Floor Tarquinia (VT) 1100 1st Floor Place 1 (CNF- CRI Local Committee) Tarquinia (VT) 1990 Ground Floor Place 1 (CRI Local Committee ) Roma Ground Floor Place 1 (CNTS-LC CRI) 1953 Place 2 Ground Floor Roma 1900 Place 3 Ground Floor (VdS- CRI Provincial Committee) Place 4 1st Floor Figures 1 and 2 show the concentration of radon in the diverse centers of the Italian Red Cross (CRI) that were examined in the Campania and Lazio regions. As expected, Lazio average values were higher than Campania ones. About Figure 1, the values of 222Rn concentration found in the center at Caserta falled within 37 and 202 Bq/m3 range and the concentrations found at the ground floor were higher than on the 1st floor. This allows us to consider that the ground has an important role. Even though the building is an old one made of tufa, one cannot exclude the contribution of the building materials. The variability of data found between rooms within the same center can be attributed to the different ventilation. (10) In Pozzuoli, where the center is located entirely on the ground floor, the values were between 31 and 138 Bq/m3 rang. The graphs show the lowest concentration of radon at Pozzuoli. The only relatively high data is from place 4, which was little used during the period of exposure. The experimental data is coherent with the building typology of the CRI center in Pozzuoli. It is a new, prefabricated, cement structure (1948). In Naples, the CRI center is on the 6th floor of the building and the concentration was on the average the same in both locations: 64 Bq/m3.

Figure 1 Concentration of 222Rn in the Campania region

Rn 222 Concentration

250

200 PLA CE 1 150 PLA CE 2 PLA CE 3

Bq/m3 100 PLA CE 4 50

0 CASERTA POZZUOLI NAPOLI CRI SITES (Campania region)

About Figure 2, in Viterbo the values were between 27 to 114 Bq/m3, in Tarquinia values were between 162 to 720 Bq/m3 and in Rome they were between 70 to 1,253 Bq/m3 . Figure 2 Concentration of 222Rn in the Lazio region

Rn 222 Concentration

1400 1200 1000 PLA CE 1 800 PLA CE 2 600 PLA CE 3 Bq/m3 400 PLA CE 4 200 0 VITERBO TARQUINIA ROMA CRI SITES (Lazio region)

The concentrations found in Viterbo are relatively low. The CRI center there is located in a new, prefabricated building. Place 3 of Viterbo had a relatively higher concentration because it was never opened during the measurement period. The data for Tarquinia refer to two different CRI centers and the highest concentration of 720 Bq/m3 was found in the CRI Volunteer Center. This center is located in a Convent built in 1100 AD, entirely of tufa. The other data (162 Bq/m3 ) refers to a building constructed in 1990 which would have superior isolation between the ground and the building. The measures taken in Rome show medium to high values and in place 3, a storage area with little ventilation, the value was 1253 Bq/m3. As we expected, the highest values were measured at the ground floor level. A substantial agreement was found between the data obtained from measurements with Alphaguard and the Cr-39 dosimeters. Figure 3 contains a demonstration graph showing the concentration of radon in the Tarquinia center (Place 1). Figure 3 Concentrations of 222Rn measured with Alphaguard (Lazio region).

CRI Commitee Tarquinia

800 700 ) 3 600 500 (Bq/m 400 300 Concentration Radon 20 120 220 320 Time (min)

CONCLUSION The results of average value of indoor radon are reported in Table 4.

Table 4 Average concentration of 222Rn in CRI Centers

Region City Average indoor radon concentration (222Rn) Bq/m3 Lazio Roma 175 ± 3.0 Tarquinia 441 ± 3.0 Viterbo 71 ± 1.2 Campania Pozzuoli 61 ± 2.6 Caserta 106 ± 2.9 Napoli 64 ± 1.9

The average concentration of radon found in the localities of the CRI centers in the Campania region was within the regional average. For the centers in Lazio, the average concentrations measured in Tarquinia and Rome were higher than the average regional values. Such values cannot be directly compared to the 500 Bq/m3 which is the action level given by the legislative decree as the average annual concentration, because our results are representative of only a trimestral sampling and they have not been adjusted by seasonal factor. It would be opportune to repeat the measurements. If the repetition of the measurements in Tarquinia and Rome should confirm the data of this first campaign, it would be necessary for the two centers to enact remedial actions. (11) In Rome, frequent ventilation of the rooms could definitely constitute a first step towards improving the situation. Place 2 has a significantly lower value than the adjacent one as the former is larger and well ventilated. The work of the A.A. confirms the necessity to broaden the research and to continue to monitor the levels of radon in all of the centers that have an analogous construction in order to prevent harm to and protect the health of all Red Cross Italy workers.

Acknowledgments: the authors acknowledge the great assistance and support of Prof. Nicola Marinosci, Board of Directors, Italian Red Cross.

The authors would you like to acknowledge the great co-operation of Sig.ra A.Maria Docimo, President of the Naples Regional Board and Dott. Antonella Piacente President of the Rome Regional Board of the Italian Red Cross. We would you like to give special thanks also to the President of the Provincial Board and to Volunteers of the Italian Red Cross that participated in the first step of the study.

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