ERRICCA 2 European Radon Research and Industry Collaboration

Concerted Action European Commission Contract No: FIRI-CT-2001-20142

An Evaluation of Radon Reference Levels and Radon Measurement Techniques and Protocols in European Countries

Hugh Synnott

David Fenton

March 2005

Contents List of Figures………………………………………………………………....... ii

List of Tables……………………………………………………………………. ii

Executive Summary………………………………………………………….… iii

1. Introduction………………………………………….................................. 1

2. Description of ERRICCA 2 project ………………………………………. 1

3. Scope of review of radon measurement techniques …………………..…. 2

4. Questionnaire……………………………………………………………….. 2

5. Results……………………………………………………………..……….. 3

5.1 Recommended national reference levels..................................................... 3 Domestic environments……………………………………………………. 4 Above ground workplaces…………………………………………………. 7 Below ground workplaces…………………………………………………. 8 Drinking Water…………………………………………………………….. 10

5.2 Recommendations regarding measurement protocols…………………. 12

5.3 Requirements for commercial radon measurement companies……….. 14

5.4 Radon measurement intercomparison exercises……………………….. 16

6. Main Findings………………………………………………..……………. 17

7 Observations…….……………………………………………………..….. 18

8 Acknowledgements…………………………………………………….…. 19

9 References…………………………………………………………………. 20-

10 Appendices……………………………………………………………….... 21

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List of Figures

Figure 1 Reference levels for radon gas in domestic environments

Figure 2 Reference levels for radon gas in above ground workplaces

Figure 3a Reference levels for radon gas in underground workplaces where the

national regulatory authority has set these levels in units of radon

concentration

Figure 3b Reference levels for radon gas in underground workplaces where the

national regulatory authority has set these levels in units of radon

exposure

Figure 4a Reference levels for radon in drinking water

Figure 4b Reference levels for radon in Czech Republic drinking water

List of Tables

Table 1 Countries that responded to the questionnaire on radon measurement

techniques

Table 2 Countries that have set reference levels for radon in different

environments

Table 3 Countries whose national regulatory authorities have made statements

concerning measurement techniques and protocols for radon in air in

domestic environments, workplaces and for radon in drinking water

Table 4 Details of countries and their respective national regulatory authorities

who have imposed preconditions on commercial measurement

laboratories

Table 5 Views on the need for more national and international intercomparison

exercises

ii

Executive summary

Many international organisations concerned with radiation protection issues such as The European Commission (EC), the International Commission for Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) have made statements and issued advice on exposure to radon gas. This advice has resulted in many nations setting reference/action levels for indoor radon and radon in drinking water and carrying out radon surveys to determine areas where indoor radon exposure to people may be a problem. This information is usually presented in map form which clearly identifies areas of high radon potential.

Numerous methodologies for measuring radon in air and water are well established. However information is generally absent on radon measurement techniques and protocols used in European countries. This report addresses this issue by reviewing the radon measurement techniques used in the 20 participating countries of the European Radon Research and Industry Collaboration Concerted Action project (ERRICCA2). As a topic leader within the ERRICCA2 project, the Radiological Protection Institute of Ireland (RPII) took the lead role in gathering and evaluating the information in this report. Data was gathered by questionnaire sent to the 20 participating countries in the ERRICCA2 project seeking information on the radon measurement techniques used in each county. All 20 countries responded. This questionnaire also provided an opportunity to update information regarding radon reference levels that apply to workplaces, domestic environments and drinking water in these countries.

The questionnaire asked six questions. Question 1 sought information on reference levels for radon in air in domestic environments and workplace and for radon in drinking water. Questions 2-4 sought information on recommended protocols or techniques in each country to measure radon in air and drinking water. Question 5 enquired as to whether commercial measurement companies required laboratory accreditation, validation or similar official approval to operate a commercial radon measurement service. The final question was concerned with gathering the views from member countries regarding the necessity of international radon measurement intercomparison exercises.

The majority of countries have set references levels for radon in air in domestic environments and workplaces whereas less than 50% of countries have set a reference level for radon in drinking water. In general, reference levels for domestic environments are advisory and workplace reference levels are enforceable. For domestic environments most countries set their reference level between 200 and 400 Bq/m3, for workplaces most countries set their reference levels in the range 400-1000 Bq/m3 and 100-1000 Bq/l was the most commonly chosen reference level for radon in drinking water. In setting these levels most countries took account of advice issued by organisations such as the EC, ICRP and the IAEA.

In nine of the 20 countries surveyed, national regulatory authorities have made recommendations concerning measurement protocols and techniques for radon in air in domestic environments. Six countries have made similar recommendations for workplaces. Techniques and protocols for measuring radon differ from country to country. However most countries recommend the use of long-term passive integrating detectors to accurately determine radon concentrations in air. Five countries recommend measurement techniques and protocols for radon in drinking water. Liquid scintillation counting is the most common measurement technique for measuring radon in drinking water.

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Twelve countries have imposed or are in the process of imposing requirements such as laboratory accreditation for official approval of companies wishing to operate a commercial radon measurement laboratory. Five countries require ISO 17025 laboratory accreditation to carry out indoor radon measurements in air. One country (Finland) requires laboratories wishing to carry out commercial radon measurements in drinking water to be accredited. The majority of the remaining countries require measurement laboratories to demonstrate compliance with predefined criteria laid down by the national regulatory authority which specified the measurement techniques and protocols to be used and the method by which results are reported.

The need for future national and international intercomparison exercises was considered. Eleven countries surveyed expressed a preference for further intercomparison exercises. Eight countries were not in favour of this indicating that the National Radiological Protection Board (NRPB) intercomparison scheme was adequate.

While this report does show common approaches adopted by countries in dealing with radon such as the setting of indoor reference levels for radon gas it is not the purpose of this report to advise or to recommend to individual countries as to what course of action one should take. However some observations are possible following a full evaluation of the data.

• There is sufficient information available to allow countries that have yet to set reference levels to make an informed decision on the necessity to do so.

• It is a matter for individual countries when considering what measurement protocols and techniques to implement. The use of long-term passive integrating techniques for measuring radon in air is preferred by most countries. Countries whose national regulatory authorities have yet to make formal recommendations regarding radon measurement techniques and protocols should give consideration to adopting this technique. However it is advisable to draw upon the experiences and expertise of countries that can demonstrate a proven track record in this regard.

• Under a laboratory accreditation scheme a radon measurement company can demonstrate that it has robust procedures and appropriately trained personnel in place. However laboratory accreditation in itself may not be sufficient to assess if a particular measurement laboratory can satisfactorily measure radon. Successful participation in a scheme similar to the NRPB’s intercomparison exercise or other validation scheme can demonstrate a laboratories ability to successfully measure radon. Participation in an intercomparison exercise can complement laboratory accreditation and the two combined would strengthen confidence in the measurement company.

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1. INTRODUCTION Radon gas is ubiquitous in the environment and exposure to its decay products represents what is for most people their greatest source of radiation dose. Radon gas, given certain conditions, can build up to unacceptable concentrations upon entry into a building. Fortunately it is possible to significantly reduce the radon concentrations in a building should this prove necessary. Measures commonly taken to reduce radon concentrations in buildings are relatively inexpensive and can result in substantial reductions in radiation doses to occupants of the buildings.

International organisations such as the International Commission on Radiological Protection (ICRP), the International Atomic Energy Agency (IAEA), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the European Commission (EC) have made numerous statements on radon gas [EC, 1990; ICRP 1994; EC, 1997; UNSCEAR, 2000; IAEA, 2003]. Much of this advice focuses on setting radon reference/action levels for radon in air for different building types, producing maps showing areas of high radon potential and incorporating radon preventive measures into new constructions. As a result many countries now have active radon programmes in operation. The ICRP has considered radon in numerous publications and this has been summarised by Akerblom [1998].

The terms action level and reference level feature continuously in the scientific literature in relation to radon gas. An action level is defined as a radon level above which an intervention is recommended to reduce the exposure in a building. A reference level is defined as a radon concentration above which some specified action or decision should be taken. For the purposes of this report the term action level will be referred to as a reference level.

2. DESCRIPTION OF ERRICCA2 PROJECT

ERRICCA1 (European Radon Research and Industry Collaboration Concerted Action) identified a number of areas where future work was required. Following consultation with various European organisations with an interest in radon, the following topic areas were identified for further work under the ERRICCA2 project:

• Development of a European radon website

• Increasing public awareness and confidence

• Radon protection of new buildings

• Radon mitigation of existing buildings

• Radon in building materials

• Mapping and measurement of radon.

As leader for topic area 6 on the mapping and measurement of radon, the Radiological Protection Institute of Ireland (RPII) took a lead role in gathering and evaluating information on radon measurement reported here. Information on radon mapping is reported by Synnott and Fenton [2005].

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A new development in ERRICCA2 was the establishment of an industrial forum as a means of promoting the knowledge of risks associated with radon exposure to employers, workers and the general population. This was achieved through the holding of national and international forums for the duration of the project.

3. SCOPE OF THE REVIEW OF RADON MEASUREMENT TECHNIQUES

As part of the ERRICCA1 project Akerblom [1998] undertook a comprehensive review of radon legislation and national guidelines in EU countries as well as in a significant number of countries outside the EU. Akerblom reported on reference levels for radon in air in domestic and workplace environments. One of the aims of the ERRICCA2 project was to update this information for ERRICCA2 participant countries, for example, by compilng information on the reference levels chosen by Member States on implementing the provisions of Council Directive 96/29/Euratom [EC, 1996] which lays down the basic safety standards for the protection of workers health from ionising radiation including controllable natural sources such as radon. It was also thought that information on radon reference levels for drinking water would be valuable following the Commission Recommendation of December 2001 2001/928/Euratom [EC, 2001] which lays down recommendations for the protection of members of the public from radon in drinking water for EU Member States.

Numerous methodologies for measuring radon in air and water are now well established. However radon measurement techniques and protocols were not fully documented. Specifically ERRICCA2 sought to answer the following questions

• What do various national regulatory/advisory bodies recommend with respect to radon measurements?

• What reference levels are currently in force for radon in air in domestic environments and in drinking water?

• What is the position within countries with regard to approval, certification, validation and accreditation of radon measurement services?

• Is there a need for national and international intercomparison exercises?

4. QUESTIONNAIRE

Information on the extent of radon measurement techniques and protocols was sought through a questionnaire which was sent to all the ERRICCA2 members. The response was excellent and all 20 ERRICCA2 member countries replied to the questionnaire (Table 1). Details of the questions asked and the participant responses are given in Appendix 1.

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Table 1

Countries that responded to the questionnaire on radon measurement techniques

Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary,

Ireland, Italy, Netherlands, Poland, Portugal, Romania, Slovenia, Spain, Sweden,

Switzerland, United Kingdom.

5. RESULTS

5.1 Recommended national reference levels Table 2 shows the countries that have set reference levels. All countries except the Netherlands and Portugal have set one or more reference levels for radon in their respective countries. The majority of countries have set reference levels for radon in domestic and workplace environments, however less than 50% of countries have a reference level for radon in drinking water. Seven countries have set reference levels for all four categories. More comprehensive information on reference levels is available in Appendix 1.

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Table 2

Countries that have set reference levels for radon in different environments

Country Domestic Workplace

(above ground)

Workplace

(below ground)

Drinking

water

Austria yes no no no

Belgium yes yes yes no

Czech Republic yes yes yes yes

Denmark yes yes yes yes

Finland yes yes yes yes

France no yes no no

Germany yes yes yes yes

Greece yes yes yes yes

Hungary no yes yes no

Ireland yes yes yes yes

Italy no yes yes no

Netherlands no no no no

Poland no no yes no

Portugal no no no no

Romania no no yes no

Slovenia yes yes yes no

Spain yes no no no

Sweden yes yes yes yes

Switzerland yes yes yes no

United Kingdom yes yes yes no

Domestic environments

Thirteen countries have set reference level(s) for radon in air for domestic environments, the majority of which are in the range 200- 400 Bq/m3 (Figure 1). This is at the lower end of the 200–600 Bq/m3 recommended by ICRP [ICRP, 1994]. However it is in line with the 1990 European Commission recommendations for radon in domestic environments [EC, 1990].

Seven countries have set two reference levels for radon in domestic environments. In Austria, Czech Republic, Finland, Germany and Greece the higher level applies to existing dwellings and the lower one applies to new constructions. In Switzerland the higher reference level is enforceable whereas the lower level is advisory. Both these reference levels apply to new and existing buildings. Denmark has also set two reference levels for domestic environments, but these reference levels refer to the type of intervention required to reduce radon concentrations. At radon concentrations of between 200 and 400 Bq/m3 interventions of a relatively minor

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nature are taken, for example, an improvement in ventilation. At radon concentrations above 400 Bq/m3 more robust intervention is warranted to reduce radon concentrations such as, for example, the provision of a sub slab depressurisation system.

In general, reference levels are advisory and it is ultimately the decision of the householder whether to take remedial action to reduce radon concentrations. A number of countries however have reference levels for dwellings which are compulsory. For example, the 200 Bq/m3 reference level that applies to new and existing constructions in Sweden is compulsory as is the 1000 Bq/m3 reference level in Switzerland and the 200 Bq/m3 reference level that applies to new Finnish dwellings. The maximum permitted radon concentrations allowed in Czech domestic dwellings is 4000 Bq/m3 (not shown in Figure 1). In Sweden the responsibility for enforcing the 200 Bq/m3 reference level lies with local authorities and if measurements show radon concentrations above 200 Bq/m3 the local authority can force the householder to mitigate. In this regard enforcement orders are issued on a regular basis to owners of large dwellings where more than one family is located. In relation to single family homes with elevated radon levels information campaigns are regularly used to highlight the radon issue and the hence the need to carry out remedial work and enforcement orders are very seldom used in such instances. In Switzerland, the Cantons (regions) are responsible for enforcing radon reference levels. They must order the necessary remedial measures if they are not undertaken by the house owner. The cost of all remedial work is borne by the householder. In Finland the 200 Bq/m3 reference level for new buildings is set out in the Building Code of Finland. The reference level for radon in existing houses is given in a decree of the Ministry of Social Affairs and Health and is not compulsory.

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Figure 1

Reference levels for radon gas in domestic environments

0 200 400 600 800 1000 1200

UK

Switzerland

Sweden

Spain

Slovenia

Romania

Portugal

Poland

Netherlands

Italy

Ireland

Hungary

Greece

Germany

France

Finland

Denmark

Czech Republic*

Belgium

Austria

Cou

ntry

Bq/m3

Compulsory reference level

Advisory reference level

*The maximum permitted radon concentration in the Czech Republic is 4000 Bq/m3. This is not shown in

the above figure.

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Above ground workplaces

Fourteen countries have set reference levels for radon in air in above ground workplaces. These range from 200–3000 Bq/m3. Belgium, however expresses it’s reference level for above ground workplaces in terms of radon exposure at 800 kBq/m3h/year (not shown in Figure 2). All countries except Switzerland have reference levels below 1000 Bq/m3. This is in line with recommendations contained in Radiation Protection 88 [EC, 1997] and ICRP 65 [ICRP, 1994].

Figure 2

Reference levels for radon gas in above ground workplaces

0 500 1000 1500 2000 2500 3000 3500

UK

Switzerland

Sweden

Spain

S lovenia

Rom ania

Portugal

Poland

Netherlands

Ita ly

Ire land

Hungary

G reece

G erm any

France

Fin land

Denm ark

Czech Republic

Belg ium *

Austria

Cou

ntry

B q /m 3

*Belgium expresses their reference level for above ground workplaces in terms of radon exposure. The

figure chosen is 800 kBq/m3h/year.

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Radiation Protection 88 [EC, 1997] recommends that workplace reference levels in EU Member States should be set in the range 500–1000 Bq/m3. This should ensure that no worker receives an effective dose from radon greater then 6 mSv which is the dose at which a worker must be designated as a category A worker [EC, 1996]. However Member States are free to set a reference level below the specified range if they so wish.

Germany, France and Ireland have set two reference levels for workplaces. In Germany these reference levels apply to domestic type buildings such as offices, kindergartens etc. The lower 200 Bq/m3 figure is a design level for new buildings whereas the higher 400 Bq/m3 level applies to existing buildings. A reference level of 100 Bq/m3 for new and existing buildings is being considered. In France the reference levels only apply to workplaces that have a significant public occupancy such as prisons, hospitals, retirement homes, schools, etc. Simple remedial measures must be implemented when indoor radon concentrations are above 400 Bq/m3, however more extensive remedial work must be undertaken in public buildings with radon concentrations above 1000 Bq/m3. In Ireland an advisory reference level of 200 Bq/m3 applies to schools and long stay institutions such as prisons and nursing homes.

In the majority of countries, reference levels for above ground workplaces are enforceable and if radon concentrations exceed the specified reference level action is required to reduce the risk from exposure to radon.

Below ground workplaces Fifteen countries have set radon reference levels for underground work places (see Figures 3a and 3b). The majority of countries have expressed this reference level in terms of radon concentration (Figure 3a). However Germany, Sweden and Belgium have given this reference level in terms of exposure (Figure 3b). As with above ground workplaces the majority of countries have set reference levels in the range 400–1000 Bq/m3.

No underground worker in Poland is allowed to receive a dose from radon in excess of 20 mSv in any one year. Radon concentrations are not routinely measured in Polish underground workplaces. It is a requirement however to routinely measure the potential alpha energy concentrations in such workplaces.

In Romania the total exposure to radon an underground worker is allowed is 4 working level months per year.

In countries where the national regulatory authority has set reference levels in units of radon exposure, the range is 800 to 2500 kBq/m3h/year. This is equivalent to 400 to 1250 Bq/m3 of radon gas concentration during working hours assuming an equilibrium factor of 0.4 and 2000 hours per year spent at work.

Under the German Radiation Protection Ordinance a control level of 6 mSv per year, equivalent to a radon exposure 2000 kBq/m3h/year, applies to workers in caves, mines, waterworks and spas. The legal effective dose limit from radon exposure for underground workers in Germany is 20 mSv per year which corresponds to a radon exposure of 6000 kBq/m3h/year.

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Figure 3a

Reference levels for radon gas in underground workplaces where the national regulatory authority has set these levels in units of radon concentration

0 500 1000 1500 2000 2500 3000

UK

Switzerland

Spain

Slovenia

Romania**

Portugal

Poland*

Netherlands

Italy

Ireland

Hungary

Greece

France

Finland

Denmark

Czech Republic

Austria

Cou

ntry

Bq/m3

*No underground worker in Poland is allowed to receive a dose from radon in excess of 20 mSv in any

one year

**The total exposure from radon which a Romanian underground worker is allowed to receive in any one

year is 4 working level months

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Figure 3b

Reference levels for radon gas in underground workplaces where the national regulatory authority has set these levels in units of radon exposure

0 500 1000 1500 2000 2500 3000

Sweden

G erm any

Belg ium

Cou

ntry

kB q /m 3h per year

Drinking water Seven countries (Denmark, Finland, Germany, Greece, Ireland, Sweden and the Czech Republic) have set reference levels for radon in drinking water. Reference levels are in the range 20 to 1000 Bq/l (see Figures 4a, 4b) which is in broad agreement with EU recommendations on the protection of the public against exposure to radon in drinking water supplies [EC, 2001]. The United Kingdom has not formally set reference levels for radon in drinking water but adheres to EC guidelines as laid down in 2001/928/Euratom [EC, 2001]. In Poland the radiation dose from all radionuclides in drinking water including radon must not exceed 0.1 µSv per year.

In countries that have taken account of EC recommendations on radon concentrations in drinking water, the lower value applies to public water supplies whereas the higher value applies to private water supplies. This difference is a reflection of the duty of care that water providers have for their customers.

The German Commission on Radiological Protection recommends a reference level of 100 Bq/l which applies to public and private water supplies.

The Italian National Health Council has proposed a reference level of 100 Bq/l be set for mineral water and that infants should not consume mineral water containing radon with a concentration above 32 Bq/l.

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Figure 4a

Reference levels for radon in drinking water

0 200 400 600 800 1000

UK***

Switzerland

Sweden

Spain

Slovenia

Romania

Portugal

Poland**

Netherlands

Italy*

Ireland

Hungary

Greece

Germany

France

Finland

Denmark

Belgium

Austria

Cou

ntry

Bq/m3

Public water supply

Private water supply

Mineral water

All drinking water

*A recommendation has been made by the Italian National Health Council to the Ministry of Health that

a reference level of 100 Bq/l be considered mineral water and that infants should not consume mineral

with radon concentrations above32 Bq/l

**In Poland the radiation dose from all radionuclides including radon must exceed 0.1 uSv per year

***EC guidance on radon concentrations in drinking water (2001/928/Euratom) is adhered to

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The Czech Republic has the most comprehensive set of reference levels for radon in drinking water (Figure 4b). Advisory reference levels of 20, 50 and 100 Bq/l have been set for bottled water for infants, bottled water and public water supplies, and bottled natural mineral water respectively. Respective maximum permitted levels of 100, 300 and 600 Bq/l also apply to these three categories of drinking water.

Figure 4b

Reference levels for radon in Czech Republic drinking water

0 100 200 300 400 500 600 700

Bottled water forinfants

Bottled water/supplied drinking

water

Bottled naturalmineral water

Bq/l

Maximum permittedlevelsGuidance levels

5.2 Recommendations regarding measurement protocols National regulatory authorities in nine of the respondent countries have issued recommendations/guidelines for the measurement of radon in air in domestic environments. Seven have made statements concerning radon in workplaces whereas six have issued guidance on radon in drinking water.

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Table 3

Countries whose national regulatory authorities have made statements concerning measurement techniques and protocols for radon in air in domestic environments,

workplaces and for radon in drinking water Domestic Environments Workplaces Drinking Water

Yes (9) No (11) Yes (6) No (14) Yes (5) No (15)

Austria

Czech-Republic

Finland

France

Ireland

Poland

Sweden

Switzerland

United Kingdom

Belgium

Denmark

Germany*

Greece

Hungary

Italy

Netherlands

Portugal

Romania

Slovenia

Spain

Czech Republic

Finland

France

Ireland

Sweden

Switzerland

Austria

Belgium

Denmark

Germany*

Greece

Hungary

Italy***

Netherlands

Poland*

Portugal

Romania

Slovenia

Spain

United Kingdom

Czech Republic

Finland

Germany

Ireland

Romania

Austria

Belgium

Denmark

France**

Greece

Hungary

Italy

Netherlands

Poland

Portugal

Slovenia

Spain

Sweden

Switzerland

United Kingdom

*No specific technique or protocols recommended but measurements must be carried out by an

accredited laboratory (PN-EN ISO/IEC 17025:2001).

**Protocols in preparation

***Proposed for underground workplaces

The most common measurement technique reported for measuring radon in air in domestic environments and workplaces is the use of a long term (one month to one year) passive integrating detector. Some countries such as Sweden, Finland and France recommend that measurements are carried out during the heating season (October to April) as during this period higher radon concentrations indoors would be expected. Other countries, for example United Kingdom and Ireland, carry out radon measurements over any three-month period throughout the year and apply seasonal correction factors to the measurements.

Recommendations by national regulatory authorities on measurement protocols for drinking water are at a less advanced stage. The most common measurement technique used for measuring radon in drinking water is liquid scintillation counting.

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Specific details of radon measurement protocols and techniques used by each country are given in Appendix 1.

5.3 Requirements for commercial radon measurement companies Twelve countries have imposed or are in the process of imposing conditions on commercial radon measurement laboratories wishing to carry out indoor radon measurements (Table 4). The imposed or proposed conditions vary from country to country and are fully described in Appendix 1.

Accreditation according to ISO 17025 is a general requirement for all Austrian testing laboratories.

In the Czech Republic commercial radon measurement laboratories must be licensed by the State Office for Nuclear Safety.

In Finland, STUK has issued requirements for accepted indoor radon measurement equipment. For both integrating devices and monitors used for continuous measurements, these requirements include the measurement range, standard deviation of repeated measurements and the total accuracy. STUK also states that commercial laboratories wishing to carry out radon measurements in drinking water must be accredited.

In France the Health Ministry lays down preconditions for commercial radon measurement companies wishing to carry out radon measurement in workplaces. Laboratories should have implemented a quality system and be technically competent to carry out radon measurements.

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Table 4

Details of countries and their respective national regulatory authorities who have imposed preconditions on commercial measurement laboratories

Preconditions

Imposed (12)

Name of Regulatory

Authority who imposed

preconditions

Type of Preconditions

Austria No details given Accreditation to ISO 17O25

Czech Republic

State Office for Nuclear

Safety (SONS)

Commercial measurement companies must

have licence issued by SONS

Finland Radiation and Nuclear

Safety Authority of Finland

(STUK)

STUKs requirements for radon measurements

include; range, standard deviation of repeated

measurements and total accuracy

France

French Health Ministry

Commercial measurement companies must have

a quality system in place and be technically

competent to measure radon

Germany Federal Office for Radiation

Protection (BfS)

Commercial measurements companies wishing

to undertake measurements in domestic

environments and workplaces must be

accredited to ISO 17025 or its equivalent

Ireland

Radiological Protection

Institute of Ireland (RPII)

Commercial measurements companies wishing

to undertake measurements in workplaces must

be accredited to ISO 17025 or its equivalent

Italy No details available The 2000 law implementing the EU Directive

96/29 establishes that laboratory accreditation

should be made at central level and this has not

yet happened. However accreditation at a local

level is underway

Poland Economic Ministry in

agreement with the Polish

Atomic Energy Agency

Commercial measurements companies wishing

to undertake measurements in workplaces must

be accredited to ISO 17025 or its equivalent

Romania No details available No details available

Spain Nuclear Safety Council

(CSN)

Under discussion between CSN and Catalonia

Politechnical University

Switzerland

Swiss Federal Office of

Public Health (SFOPH)

All radon measurements shall be recognised by

SFOPH

United Kingdom National Radiological

Protection Board (NRPB)

Commercial radon measurement laboratories

must be validated

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In Germany commercial measurements companies wishing to undertake measurements in domestic environments and workplaces must be accredited to ISO 17025 or its equivalent.

In Ireland commercial radon measurement companies wishing to undertake radon in air measurements in workplaces must be accredited to ISO 17025 or its equivalent. This requirement does not extent to carrying out measurements in drinking water or radon in air in domestic environments.

Italian legislation which implements Council Directive 96/29/Euratom requires that laboratory accreditation of commercial radon measurement laboratories be centrally coordinated. This has yet to happen. However, accreditation at a local level is underway.

In Poland commercial laboratories wishing to carry out radon measurements in workplaces must be accredited to ISO 17025.

In Spain the development of a protocol for the accreditation of laboratories carrying out radon measurements by means of an agreement between the Nuclear Safety Council (CSN) and the Catalonia Politechnical University is being undertaken.

In Switzerland all commercial radon measurements must be recognised by the Swiss Federal Office for Public Health (SFOPH)

In the United Kingdom the National Radiological Protection Board recommends that commercial measurement laboratories be validated. This requires that every six months laboratories meet conditions laid down in a performance test which demonstrates their competence to measure radon and report results. Details of the NRPB validation scheme are given in Miles and Howarth [2000].

5.4 Radon measurement intercomparison exercises Opinion is equally divided as to whether there is a necessity to carry out further intercomparison exercises. Sweden, United Kingdom and Italy indicated that the intercomparison exercise run by NRPB is sufficient. The United Kingdom however suggested that it would be of interest to have intercomparisons of active devices although it recognised that this would be expensive and difficult to operate. Italy said that it would be useful to compare the performance of European and US measurement laboratories and to work in close cooperation with metrological institutes. In Switzerland, SFOPH has mandated the PSI to organise yearly an intercomparison exercise in its accredited radon chamber.

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Table 5

Views on the need for more national and international intercomparison exercises Yes (11) No (8)

Austria

Belgium

Czech Republic

Finland

Greece

Hungary

Poland

Portugal

Romania

Switzerland

Spain

Denmark

Germany

Ireland

Italy

Netherlands

Slovenia

Sweden

United Kingdom*

*UK indicated that while the present intercomparison was adequate for passive detectors a similar

intercomparison for active detectors may be worthwhile.

France did not provide any information

A programme entitled “Comparison of Calibration Facilities for Radon Activity Concentration” is also under consideration of Euromet (project N° 657, www.euromet.org). This project was initiated by Rn-DACH (an informal platform of “german speaking” representatives from Germany, Austria, Switzerland, Italy, Belgium, Luxemburg and Czech Republic). A report from the Euromet project was not available at time of writing this report.

6. MAIN FINDINGS

• Thirteen countries have set reference levels for radon in air in domestic environments. The majority of countries set this reference level in the range 200 -400 Bq/m3. In most countries the domestic reference level is advisory with the exception of Czech Republic, Finland, Sweden and Switzerland which have set compulsory reference levels.

• Fourteen and fifteen countries respectively have also set reference levels for radon in air for above and below ground workplaces. Occupational exposure to radon is treated differently from exposure to radon in domestic environments insofar as most countries have set reference levels which are enforced. The most frequently chosen reference level for radon in above and below ground workplaces is 400 Bq/m3; however some countries choose to express reference levels in underground workplaces in terms of radon exposure.

• Seven countries have set references levels for radon in drinking water. The UK has not formally set a reference level for drinking water but adheres to EC guidelines on this

17

issue. The majority of these countries have set at least two reference levels: the lower level, most commonly 100 Bq/m3, applies to public water supplies, whereas the higher level, most commonly 1000 Bq/m3, applies to private water supplies.

• The national regulatory authority or Government advisory body for radiological matters in nine countries have recommended techniques or protocols for measuring radon in air in domestic environments. Only six countries have recommended techniques or protocols for measuring radon in air in workplaces. The most common technique stated for measuring radon in air in both domestic and workplace environments is the use of long-term passive integrating detectors.

• The national regulatory authorities or government advisory bodies for radiological matters in five countries have made recommendations concerning radon measurement protocols or techniques in drinking water. The most common technique for measuring radon is liquid scintillating counting.

• Twelve countries have imposed or are considering imposing preconditions on the operation of commercial radon measurement laboratories. Accreditation to ISO 17025 is a requirement in five countries. In the majority of the remaining countries, commercial radon measurement companies must comply with requirement set out by their respective regulatory authority for radiological matters or its equivalent.

• There was an approximately 50:50 split as to the need for future intercomparison schemes. Several countries suggested that the NRPB intercomparison exercise was adequate.

7. OBSERVATIONS

• The purpose of this report is to show how individual countries have addressed the setting of reference levels for radon, the development of radon measurement techniques or protocols and the regulation of commercial radon measurement laboratories. It is not the purpose of this report to issue formal recommendations to individual countries in relation to these issues. Nonetheless a number of observations are possible following a full evaluation of the data.

• It is now well established that setting reference levels for radon in air in dwellings and workplaces is one of the principal foundations of an active radon campaign. Countries that have yet to set reference levels may use the experience of other countries to now consider doing so. Akerblom [1998] recommends that countries that have a serious radon problem should set compulsory reference levels placing emphasis on new buildings with radon legislated into planning and building codes.

• The use of long-term integrating passive techniques for measuring radon in air is the most common method used by countries surveyed in this report. Countries that have yet to formally recommend techniques for measuring radon in air should consider the use of a long-term passive integrating technique such CR-39 detection plastics. However the choice of what radon measurement technique to use should be made by

18

individual countries based on their experience and available expertise in measuring radon.

• Measurement protocols seem to have been decided by individual countries based on their experience to date in measuring radon. This perhaps explains why measurement protocols vary from country to country. This report cannot recommend a specific radon measurement protocol but can make a general observation that whatever protocol is chosen must complement the chosen measurement technique. Countries with no formally recommended radon measurement protocols could draw upon the experiences of other countries with a proven track record in this area before ultimately deciding upon which protocols and techniques best suit their circumstances.

• The measurement of radon in drinking water is at a less advanced stage. The measurement technique used by the majority of countries that carry out such measurements is liquid scintillation counting.

• Under a laboratory accreditation scheme a measurement company can demonstrate that it has robust procedures and appropriately trained personnel in place. However laboratory accreditation in itself may not be sufficient to assess if a particular measurement laboratory can satisfactorily measure radon. Successful participation in a scheme similar to the NRPB’s intercomparison exercise or other validation scheme can demonstrate a laboratories ability to successfully measure radon. Laboratory accreditation and radon measurement intercomparison exercises are complementary and the two combined would strengthen confidence in the measurement company.

8. ACKNOWLEDGEMENTS

This work was carried out under Contract No: FIRI-CT-2001-20142 of the European Commissions 6th Framework Programme.

The authors also wish to acknowledge the financial support of the European Commission without which this would not have been possible.

The authors of this report wish to thank all the participants of the ERRICCA2 project for all the information they provided and for their constructive comments on the text.

19

9. REFERENCES Akerblom, G. 1998. Radon Legislation and National Guidelines. SSI-99/18, Stockholm: Swedish Radiation Protection Institute. EC, 1990. Commission recommendation of 21 February 1990 on the protection of the public against indoor exposure to radon. (90/143/Euratom). Official Journal of the European Commission 1996 39 L80 26-27. EC, 1996. Council Directive 96/29/Euratom of 13 May 1996 laying down the basic safety standards for the protection of health of workers and the general public against the dangers of ionising radiation. Official Journal of the European Commission 1996 39 L159 1-114. EC, 1997. Recommendations for the implementation of Title VII of the European Basic Safety Standards concerning significant increases in exposure due to natural radiation sources. Radiation Protection 88. European Commission, Office for Official Publications of the European Commission. Radiation Protection Series EC, 2001. Commission recommendation of 20 December 2001 on the protection of members of the public to exposure of radon in drinking water supplies. 2001/928/Euratom. Official Journal of the European Commission, L344, 85-88. IAEA, 2003. Radiation protection against radon in workplaces other than mines. International Atomic Energy Agency, Safety Report Series no. 33. Vienna. ICRP, 1994. Protection against radon-222 at home and at work. International Commission on Radiological Protection, Publication 65. Oxford: Pergamon Press. Miles, J and Howarth, C.B. 2000. Validation scheme for laboratories making measurements of radon in dwellings. NRPB-M1140 National Radiological Protection Board, Chilton, Didcot, Oxfordshire. Synnott, H and Fenton D. 2005. An Evaluation of Radon Mapping Techniques in Europe. Project deliverable for the European Radon Research and Industry Collaboration Concerted Action project. Contract No: FIRI-CT-2001-20412 of the European Commissions 6th Framework Programme. www.rpii.ie/reports UNSCEAR, 2000. Sources and effects of ionising radiation. United Nations Scientific Committee on the Effects of Atomic Radiation, UNSCEAR 2000 report to the General Assembly. New York.

20

10. APPENDICES Appendix 1

Response of members to measurement questionnaire Answers from Austria (AT), Belgium (BE), Czech Republic (CZ), Denmark (DK), Finland (Fl) France (FR), Germany (DE), Greece (GR), Hungary (HU), Ireland (IE), Italy (IT), Netherlands (NL), Poland (PL), Portugal (PT), Romania (RO), Slovenia (SL), Spain (ES), Sweden (Se), Switzerland, (CH), United Kingdom (UK).

1 Has your national regulatory authority or Government advisory body on radiological protection issues made any statements regarding recommended national radon reference levels for radon exposure in domestic environments, in workplaces (both above and below ground) and from drinking water supplies in your country? yes (18) no (2)

AT, BE, CH, CZ, DE, DK, ES, Fl, FR, GR, HU, IE, IT, PL, RO, SE, SL, UK NL, PT

1a: If yes, what are the recommended national references levels in your country? Country Domestic Workplace

(Above Ground) Workplace (Below Ground)

Radon in Drinking Water

Austria 200 Bq/m3 (new buildings) 400 Bq/m3 (existing buildings)

none none none

Belgium 400 Bq/m3 800 kBq/m3h/year 800 kBq/m3h/year

none

Czech Republic

200 Bq/m3; 400 Bq/m3

4000 Bq/m3

1000 Bq/m3 1000 Bq/m3 20-600 kBq/m3

Denmark 200: 400 Bq/m3 400 Bq/m3 400 Bq/m3 100: 1000Bq/l

Finland 200 Bq/m3 (new buildings) 400 Bq/m3 (existing buildings)

200 Bq/m3 (new buildings) 400 Bq/m3

(existing buildings) annual working hours 1600

400 Bq/m3 (annual working hours 1600)

300 Bq/l (waterworks) 1000 Bq/l (private water supplies)

France none 400 Bq/m3; 1000 Bq/m3 (spas, hospitals, prisons, etc)

none none

Germany: 200 Bq/m3 (new buildings) 400 Bq/m3 (existing buildings)100 Bq/m³ under discussion

For waterworks and radon spas: Reference level of 2000 kBq/m³h Limit of 6000 kBq/m³h

Reference level of 2000 kBq/m³h Limit of 6000 kBq/m³h

100 Bq/l recommended

21

1a: If yes, what are the recommended national References Levels in your Country? continued

Country Domestic Workplace (Above Ground)

Workplace (Below Ground)

Radon in Drinking Water

Ireland 200 Bq/m3 400 Bq/m3 400 Bq/m3 500 Bq/l (public water supplies): 1000 Bq/l private water supplies

Italy none 500 Bq/m3 500 Bq/m3 100; 32 Bq/l

Poland none none 1, 20 mSv 0.1 uSv/y

Romania none none 1110 Bq/m3 (4WLM)

none

Slovenia 400 Bq/m3 1000 Bq/m3 1000 Bq/m3 none

Spain 200 Bq/m3 none none none

Sweden 200 Bq/m3 400 Bq/m3 2500 kBq/m3h per year

100; 1000 Bq/l

Switzerland 400; 1000 Bq/m3

3000 Bq/m3 3000 Bq/m3 none

UK 200 Bq/m3 400 Bq/m3 400 Bq/m3 As in 2001/928/Euratom

Further information on Reference Levels is given below

Czech Republic: • Domestic Environments: 200 Bq/m3 in living or accommodation rooms in new

buildings and 400 Bq/m3 in living and accommodation rooms in existing (old) buildings. The maximum permitted level of radon concentration in living or accommodation rooms is 4000 Bq/m3.

• Workplaces: The guidance reference level is 1000 Bq/m3 for all workplaces. • Drinking Water: Guidance levels and maximum permitted levels are defined only for

suppliers of drinking water to general public. Guidance levels are: 20 kBq/m3 for bottled water for infants; 50 kBq/m3 for bottled water, or supplied drinking water; 100 kBq/m3 for bottled natural mineral water. Maximum permitted levels are: 100 kBq/m3 for bottled water for infants; 300 kBq/m3 for bottled water, or supplied drinking water; 600 kBq/m3 for bottled natural mineral water. As for private sources of drinking water, the above mentioned levels are only recommended. The guidance level means an index or a criterion used for the evaluation of the radiation protection level in the case where details on radiation activities or interventions enabling to evaluate the optimisation of radiation protection in particular given case are not available. The maximum permitted level means an index or a criterion for regulation of inadmissible exposure to natural radionuclides.

Denmark:

• Domestic Environments; 200 Bq/m3 (above which minor remedial work required), 400 Bq/m3 (above which major remedial work required).

• All workplaces; 400 Bq/m3 (average for working hours). • Drinking water; the radiation protection authorities in Denmark, Finland, Iceland,

Norway and Sweden have made the following recommendations: The recommended exception for radon in drinking water is 100 Bq/l. The recommended upper level for radon in drinking water is 1000 Bq/l.

• Danish reference levels are advisory for domestic environments and compulsory for workplaces.

22

Further information on Reference Levels is given below (continued)

Finland: • In Finland an advisory (400 Bq/m3: existing buildings) and compulsory (200 Bq/m3

new buildings) exists for domestic environments and above ground workplaces. However legislation dealing with real estate transactions makes the 400 Bq/m3 reference level in effect compulsory.

• The two stated reference levels for radon in Drinking Water (300 Bq/l public water supplies) and (1000 Bq/l private water supplies) are compulsory.

France: • No Reference levels exist for radon in air for domestic environments, underground

workplaces and drinking water. • However IRSN recommend that householders carry out remedial work in domestic

environments should radon levels exceed 1000 Bq/m3. • For some above ground workplaces i.e. workplaces that have a high public

occupancy such as prisons, hospitals, residential care centres etc. an advisory (400 Bq/m3) and compulsory (1000 Bq/m3) reference levels exist.

Germany: • Underground workplaces; For workers in mines, caves and visitor caves,

waterworks, medical radon baths, and galleries compulsory regulated by the Radiation Protection Ordinance: Control Level; 6 mSv/y, equivalent to 2000 kBq/m3h per year. Legal limit 20 mSv/yr which is equivalent to 6000 kBq/m3h per year.

• Drinking Water: : Recommendation of the German Commission on Radiological Protection: 100 Bq/l.

Greece: • Domestic 200 Bq/m3 (new buildings); 400 Bq/m3 (existing buildings). • Workplaces; The action levels concerning the effective dose to workers due to radon

concentration is 400 Bq/m3 (mean annual radon concentration corresponding to 2000 working hours per year). Work activities with mean annual radon concentration less than 400Bq/m3 are excluded from further investigation. Areas with work activities leading to mean annual radon concentration greater than 400 Bq/m3 but less than 1000 Bq/m3, are characterized as supervised areas and appropriate measures must be taken in order to minimize the dose, taking into account their effectiveness and cost. Areas with work activities leading to mean annual radon concentration more than 1000 Bq/m3 but less that 3000Bq/m3, are characterized as controlled areas. Special authorization by Greek Atomic Energy Commission (GAEC) is required. Work activities where the mean annual radon concentration exceeds 3000 Bq/m3, are prohibited.

• Drinking water: Implementation of 2001/928/Euratom. Ireland:

• Workplace reference revel of 400 Bq/m3 is compulsory. If a workplace has radon concentrations in excess of this level the person responsible for the workplace must carryout an evaluation to determine whether remedial work is justified.

• Domestic reference level of 200 Bq/m3 is advisory. It is up to individual householders to decide whether remedial work is justified.

Italy: • Workplaces; no remedial action is required in workplaces – except kindergartens

and schools for children up to 13 years – if no worker is exposed to an effective dose higher than 3 mSv/y.

• Drinking water; A concentration of 100 Bq/l for mineral water was suggested by the Italian National Health Council (Consiglio Superiore di Sanità) to the Ministry of Health for the renewal of the authorisations of mineral water production. The suggestion also contains an indication that infants should not consume mineral water with radon activity concentration higher than 32 Bq/l. These recommended levels for radon are accompanied by recommended levels for U, Ra and radon decay products.

23

Further information on Reference Levels is given below

Poland: • According to a Economy Ministry Decree of 28 June 2002, In underground mines

where there is a possibility of exposure to natural ionising radiation (in air, water and in sediments) results in an effective dose in excess of 1 mSv per year, prevention methods and organisation of labour are introduced to prevent exceeding the dose constraint of 20 mSv per year.

• In underground mines concentration of radon gas in air is not measured. According to the requirements described in mentioned above Decree, potential alpha energy concentration of short-lived radon daughters (paec) should be measured. The required control frequency is as follows: paec < 0.8 mJ/m3 – once every three months; paec between 0.8 and 1.4 mJ/m3 - once a month; paec > 1.4 mJ/m3 – three times a month.

Spain: • Domestic Environments: A Reference Level of 200 Bq/m3 for new domestic

dwellings is to be included in the next Spanish Technical Building Code. No reference level set for existing homes.

Sweden:

• Domestic Environments; new dwellings (National Board of Housing, Building and Planning): 200 Bq/m3, existing dwellings (National Board of Health and Welfare): 200 Bq/m3.

• Drinking Water; (National Food Administration): under 100 Bq/l: fit for consumption, over 1000 Bq/l: unfit for consumption (only waterworks distributing more than 10 m3 per day or to more than 50 persons).

• The reference levels for new buildings as well as for existing dwellings and public premises are enforced reference levels as they are found in regulations or general advice. The level for new houses is found in the Swedish Building Regulations. The reference level for existing dwellings and public premises is found in a document “General Advice on Radon”. If the radon concentration in a house is higher than 200 Bq/m3 it can be considered a detriment to human health, according to the Environmental Code. Although the reference level is found in a general advice it is considered compulsory. The reference level for existing dwellings used to be 400 Bq/m3 but was changed to 200 Bq/m3 in the beginning of July 2004.

• Workplaces; The reference level for workplaces is still 400 Bq/m3 and a compulsory. level.

Switzerland: • All Swiss domestic environment and workplace references levels are compulsory

except for a guideline value of 400 Bq/m3 that exists for radon in new and existing buildings.

United Kingdom: • Radon reference levels are advisory for domestic environments and compulsory for

workplaces. • There are no specific reference levels for radon in drinking water. The levels

specified in 2001/928/Euratom are used as a guideline.

24

2

Has your national regulatory authority or Government advisory body on radiological protection issues made any statements regarding recommended radon measurement techniques and measurement protocols for evaluating radon concentrations in domestic environments in your country?

Yes (9) No (11)

AT, CH, CZ, FR, Fl, IE, PL, SE, UK BE, DE, DK, ES, HU, GR, IT, NL, PT, RO, SL

2a A summary is given below for each recommended measurement technique and

measurement protocol in respect of domestic dwellings.

Austria • Protocols are given in Austrian Standard ÖNORM S5280-1.

Czech Republic: • Integral measurements of radon concentration in air are recommended for the

assessment of radon exposure in constructions. • The minimal required exposure period of integral measurement devices is one week. • The optimal exposure period is one year. • Continuous measures are used in special circumstances.

Finland: • The measurement method must be accepted by the national regulatory authority

(STUK). • An integrating measurement method is required Minimum measurement period: two

months. • Measurement time: heating season, November-April.

France: • NF M 60-771 : Radon 222 in buildings : methodologies applied for the screening and

for the complementary investigations Use of integrated passive measurement for the screening (normalized method – NF M 60 766) Measurement protocol described in the NF 60-771.

Ireland: • Two long-term passive radon detectors to be placed in the main living area and main

bedroom of the dwelling for a minimum period of 3 months. • The average annual radon value for the house is the seasonally adjusted average of

these two detectors. • It is this value that is compared to the Reference Level.

25

A summary is given below for each recommended measurement technique and measurement protocol in respect of domestic dwellings (continued)

Poland: • Guidelines no 352/98 issued by Building Research Institute, Warsaw, 1998, entitled

In above mentioned Guidelines requirements regarding radon measurements are presented.

• Passive methods of radon measurements are recommended: electrets for grab sampling. charcoal detectors for short time measurements (2-7 days). solid state nuclear track detectors for long time measurements (3 month – 1

year). • The above guidelines also details on the following:

Description of how to chose investigation sites. Recommended equilibrium factor: F=0.5. Requirements concerning equipment for each of recommended methods, Requirements for applied methods, concerning accuracy, precision,

detection limits, uncertainties etc. Recommendations relating to the reports of measurements.

Slovenia: • There are no formally recommended measurement techniques and protocols for

measuring radon in domestic environments. • It is the responsibility of radiation experts to choose the best possible measurement

techniques and protocols for evaluating radon concentrations in domestic environments.

Spain: • Regarding next Technical Building Code, a protocol for the measurement of radon in

new buildings has been suggested .Martin Matarranz. J.L.; “Protocol for the measurement of radon in new buildings” CSN/TGE/AEIR- /1002/1614 .October 2002.

• The Spanish laboratories usually follow EPA protocols in the measurements

Sweden: • The present measurement protocol was established in 1994. It describes how the

radon measurement should be made in order to estimate an annual mean value and compare it to action levels. It also includes recommendations for advisory short-term measurements.

• The shortest measurement period (long term measurement) is two months. The measurement has to be done during the heating season, between October and April. The device used has to be calibrated at SSI or another laboratory recommended by SSI. The protocol describes where the devices should be localised both in the building and in the room. Rooms that are frequently occupied should be measured. The result has to be representative for the radon level in rooms used for living, i.e. bedroom and living room, not the kitchen or a wet area. The minimum number of devices is two, and there has to be at least one measurement per floor. The devices should be localised in the room where the result represents the area used and where direct air-flow is likely not to affect the measurement: devices should not be placed on the floor, no closer than 25 cm from the wall, at least 1,5 meter from doors, windows or air inlets and at least 0,5 meters from air out let.

• There is information to the measurement companies about how the mean value is calculated as well as how the inaccuracy span can be estimated. The mean value shall first be calculated for each floor and then for the whole building.

26

A summary is given below for each recommended measurement technique and measurement protocol in respect of domestic dwellings (continued) Sweden continued:

• The measurement protocol also states what information the measurement report shall contain:

Name of the measurement company. Address of the house. What sort of building it is; single-family house, multi-family house and type of

ventilation system. The time period of the measurement, the date the report was established. Measurement method used. Measurement devise used, last calibration and calibration laboratory. When radon daughters have been measured information about the F-factor

must be included. The mean value for each measured room with estimated uncertainties The annual mean value or the mean value, both with inaccuracy spans

estimation. Information about visit to the house, if any. Result from gamma measurements in the house, if any. Information about action levels. Signature of the person responsible for the measurement.

• Eight measurement techniques are accepted;

Closed alpha track detectors. Open alpha track detectors. Electrets-based integrating radon meters. Activated charcoal with TLD-based integrating meter. Activated charcoal with gamma spectronomy. TLD-based integrating meter. Continuously recording filter measurement. Continuously recording radon gas measurement.

• Every method is described in more detail about calibrations and control. In 1994 a five year transitional period was given to allow measurements of radon daughters, there fore according to the protocol, only measurements of radon gas is allowed today. This protocol will be revised within 2004.

Switzerland:

• Radon gas has to be measured by a recognised measuring laboratory using passive samplers for one month minimum; 3 recommended.

• The Swiss Federal Office of Public Health shall recognise the measuring laboratories.

United Kingdom: • Measurement using passive radon detectors exposed in living room and bedroom for

at least 3 months and results corrected to estimate the annual average radon concentration.

27

3

Has your national regulatory authority or government advisory body on radiological protection issues made any statements regarding recommended radon measurement techniques and measurement protocols for evaluating radon concentrations in workplace environments (above and below ground) in your country?

Yes (6) No (14)

CH, CZ, FL, FR, IE, SE. AT, BE, DE, DK, ES, GR, HU, IT, NL, PT, PL, RO, SL UK

3a A summary is given below for each recommended measurement technique and measurement protocol in respect of workplace environments

Czech Republic: • The same as measurements in domestic environments. • Instances where the radon level is higher than 1000 Bq/m3 (guidance level), the

owner is usually obliged to ensure that measurements were carried out in accordance with a special monitoring programme approved by the Regulatory Authority (State Office for Nuclear Safety; SONS).

Finland:

• The measurement method must be accepted by the national regulatory authority (STUK).

• An integrating measurement method is required Minimum measurement period: two months.

• Measurement time: heating season, November-April. • Recommended number of measurements for large buildings has been given. • Instructions for cases where >400 Bq/m3 is observed.

o 400-<500 Bq/m3, control measurement in another season. o 500-<2000 Bq/m3, radon concentration during working hours must be

determined or radon reduction. o >2000 Bq/m3, radon reduction.

France: • NF M 60-771: Radon 222 in buildings methodologies applied for the screening and

for the complementary investigations. • Use of integrated passive measurement for the screening (normalized method – NF

M 60 766). • Measurement protocol described in the NF 60-771.

Germany: I • Guideline for measurements of radon corresponding to Radiation Protection

Ordinance of Germany. Radon Services shall be accredited according DIN EN ISO 17025. Devices for measurement shall fulfil relevant technical standards or shall be included in intercomparisons.

• It is under discussion that the use of calibrated equipment by measurement laboratories should be mandatory. And such labs should participate in annual intercomparisons.

Ireland: • The RPII recommends that radon in workplaces be measured for a minimum period

of 3 months using long-term passive detectors such as Cr39 or electret detectors. • Guidance is also given on the number of detectors to be used for the survey.

28

A summary is given below for each recommended measurement technique and measurement protocol in respect of workplace environments (continued)

Italy: • Proposed (Indeed, waiting for a National Guidance- which the law establishes should

be prepared by a National Official Committee of experts- a working group of experts of the Regions and Autonomous Provinces elaborated a detailed proposal for below ground workplaces (the first to be monitored as required by the 2000 law which implemented Title VII of the Euratom Directive 96/29).

• The proposal was adopted by the Conference of Presidents of Regions and Autonomous Provinces.

• The 2000 law, establishing the reference level for radon concentration, requires “mean annual values”. Therefore the proposal, mentioning the scarce data about “seasonal factors” in our country, suggests annual measurements (eventually divided in more than one period) with passive integrating detectors (this means nuclear track detectors or electrets), putting them at a height between 1 and 3 m.

• In the proposal other details are specified as regards how many measurements should be done in connection with room dimensions, the evaluation of the exposure of dosimeters during transit, etc).

Poland: • Regulatory Act issued by Ministry of Economy (28 June 2002) recommends: no

specific technique of radon and radon progeny concentrations measurements at workplaces but requires that such monitoring must be performed by accredited laboratory (PN-EN ISO/IEC 17025:2001).

Romania: • There are no formal preconditions laid down in Romania for commercial companies

wishing to carryout radon measurements. • Each laboratory uses different techniques, for example, alpha measurements using

filters and special radon measuring equipment. • Only one laboratory has the capability to conduct radon measurements using CR-39

detectors.

Slovenia: • There are no formally recommended measurement techniques and protocols for

measuring radon in workplace environments. • It is the responsibility of radiation experts to choose the best possible measurement

techniques and protocols for evaluating radon concentrations in workplace environments.

29

A summary is given below for each recommended measurement technique and measurement protocol in respect of workplace environments (continued)

Sweden: • Proposed guidelines for measuring radon in workplaces are as follows:

Measurements can be done in two steps. • The first step, called an orientating measurement is done as a long term integrating

measurement for at least two months. If the orientating measurement shows levels exceeding the action level a follow-up measurement has to be done.

• For the orientating measurement alpha track detectors or electrets can be used. • This follow-up measurement has to show the radon level during working hours. It can

be done either by using a continuous measurement device or an integrating method but with the ventilation system running constantly during the measurement period.

• Three measurement techniques are allowed according to the protocol: the use of closed alpha track detectors for 10 days with the ventilation

system constantly running; b) electret based integrating radon meters (5 days continuous measurements

with ventilation system constantly running or 5 day measurements with ventilation system running normally but the electret device must be closed when the working day is over and opened when the working day starts again

continuously recording radon gas monitors for 2 days. • If an annual mean level is needed the orientating measurement has to be done,

otherwise one of the follow up methods can be used immediately. • Only radon gas measurements are allowed according to the protocol.

Switzerland: • Same as Domestic Environments

4

Has your national Regulatory Authority or Government Advisory Body on radiological protection issues made any statements regarding recommended radon measurement techniques and measurement protocols for evaluating radon concentrations in Drinking Water in your Country?

Yes (5) No (15)

CZ, DE, FL, IE, RO BE, CH, DK, ES, FR, GR, HU, IT, NL, PL, PT, SE, SL, UK

4a A summary is given below for each recommended measurement technique and measurement protocol in respect of Drinking Water

Czech Republic: • Different methods approved by SONS (national regulatory authority for radiological

issues) are used (liquid scintillation, emanometric methods).

Finland: • The Act given by the Ministry of Social Affairs and Health requires the use of

methods in accordance with SFS-EN, SFS or ISO-standards or methods which are equivalent in accuracy and reliability.

• STUK recommends the use of accredited measurement services. France:

• Measurements techniques and protocols for radon in drinking water are being prepared and these will be published in the near future.

Ireland:

• The RPII uses liquid scintillation counting to measure radon in drinking water • Guidance has also been issued on how to take sample.

30

A summary is given below for each recommended measurement technique and measurement protocol in respect of Drinking Water (continued) Romania:

• Romania has a standardised method for measuring radon in drinking water. Tap is let run and after 10 min a glass bottle is filled with water and then closed with a Curie connector. In the closed system air is bubbled through the water and radon enters a Lucas Cell connected with photo-multiplier and counting system. The chamber is closed and measurements are made after 3 hours.

Switzerland: • It is recommended that measurements should be carried out according to guideline

h-=Rn 222 TWASS – 01.

5 Has your national Regulatory Authority or Government Advisory Body on radiological protection issues set down any formal preconditions such as Laboratory accreditation (ISO/IEC 17025), Laboratory approval, Laboratory certification or Laboratory validation for commercial radon measurement companies operating in your Country?

Yes (12) No (8)

AT, CH, CZ, DE, *ES, Fl, FR, IE, IT, PL, RO, UK, BE, DK, GR, HU, , NL, SE, SL

* Proposed Preconditions

5a A brief summary is given below of the formal preconditions laid down in each country for commercial radon measurement companies.

Czech Republic: • The preconditions are given in the Czech Atomic Law and the implementing legal

regulation. • Any commercial company operating in the field of radon measurements must have a

licence issued by national Regulatory Authority (SONS). • To get the licence, several requirements have to be accomplished: the application

must be accompanied by a document proving a special professional competence of a responsible representative; the quality assurance programme must be prepared, etc.

• All measurement devices must be regularly verified according to the Czech Law on Metrology.

Finland: • STUK has issued the requirements for accepted indoor radon measurement

equipments, for both integrating devices and monitors used for continuous measurements e.g. in order to check the indoor radon concentration during working hours.

• The requirements include e.g. the measurement range, standard deviation of repeated measurements and the total accuracy.

Germany: • Radon Services shall be accredited according DIN EN ISO 17025. Devices for

measurement shall fulfil relevant technical standards or shall included in intercomparisons.

Ireland: RPII. • For measuring radon in domestic dwellings no laboratory accreditation is required.

However laboratories based in Ireland wishing to carry out commercial measurements in workplaces need INAB accreditation and if based in another EU state should be approved by the relevant competent authority of that state.

31

A brief summary is given below of the formal preconditions laid down in each country for commercial radon measurement companies (continued). Poland:

• Economy Ministry in agreement with the Polish Atomic Energy Commission. • In Poland commercial laboratories wishing to carry out radon measurements in

workplaces mush be accredited to PN-EN ISO/IEC 17025:2001.

Romania: • No details available.

Spain: • Spanish preconditions are at a proposal stage and have not yet been enforced. • Laboratories doing radon measurements should have a quality assurance program in

operation to ensure the correct operation of equipment and that procedures are correctly implemented.

• Laboratories should also participate in national and international intercomparison exercises.

Switzerland: • The measuring laboratories shall be recognised by the Swiss Federal Office of Public

Health. • The requirements were laid by the SFOPH together with the Swiss Federal Office of

Metrology and Accreditation (Metas) and the Paul Scherrer Institute (PSI). • Metas has also issued a directive for the traceability of radon gas concentrations.

United Kingdom: • NRPB set down the preconditions – Laboratories may be validated if they

demonstrate that their measurement and reporting procedures are appropriate, and if they meet a performance test every 6 months. Miles, JCH and Howarth, CB. 2000. Validation scheme for laboratories making measurements of radon in dwellings: 2000 revision NRPB-M1140.

6

Do you think there is a need for more national and international radon measurement intercomparison exercises?

Yes (11) No (8)

AT, BE, CH, CZ, ES, Fl, GR, HU, PL, PT, RO, UK. DE, DK, IE, IT, NL, SE, SL, UK

6a Comments

Sweden: • The NRPB intercomparison exercise is enough.

Germany: • No national radon intercomparisons have been established.

United Kingdom: • The annual exercises by NRPB suffice for passive detectors. • It would certainly be of interest to have intercomparisons of active devices, but it

would be expensive and difficult to justify.

Italy: • long European experience was made with runs organised by NRPB. • It is necessary to coordinate the efforts in this field between national, European and

USA initiatives and between radon laboratories which already organised runs of intercomparison and metrological institutes.

Switzerland: • There should be a coordination between NRPB, BfS, PSI, etc., maybe this could be

achieved under Euromet.

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