South African Perspective for Radon in Dwellings and the

Anticipated Regulatory Control Measures

John Pule and Wilcot Speelman

NNR Regulatory Information Conference

05 – 07 October 2016

DISCLAIMER

• The information presented is not an official record of the NNR; • The NNR makes no warranties, whatsoever, either express or implied,

concerning the accuracy, completeness, reliability, or suitability of the information. Neither does it warrant that use of the information is free of any claims of copyright infringement;

• The use of particular designations of countries or territories does not imply

any judgment by the NNR as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries;

• The mention of names of specific companies or products (whether or not

indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the NNR.

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Talk Outline

• Background

• Summary from Epidemiological Studies

• International Reference Levels

• Concern about Indoor Radon

• Radon Exposure Scenarios

• Current National Situation

• Reference Levels

• Justification of the Approach

• Anticipated Legislative Changes

• Existing Exposure Situations

• Preparatory Activities

• Expected Challenges

• Way Forward

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• Radon is a naturally occurring radioactive gas • Half-life - 3.8 days with progeny generating capacity • Radon migrates from the soil into ambient and indoor air • Radon builds up inside houses when it cannot disperse • Radon progeny are electrically charged and can attach

themselves to tiny dust particles in indoor air, can be inhaled with dust particles

• Inhaled atoms decay emitting alpha radiation - can cause DNA damage

Background

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Radon Entry Mechanisms

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Summary from Studies

• Epidemiological studies confirm that radon

increases the risk of lung cancer in the general

population

• The proportion of all lung cancers linked to radon is

estimated to lie between 3% and 14%, depending

on the average radon concentration in the country

and on the method of calculation (WHO)

• Radon is the second most important cause of lung

cancer after smoking in many countries

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Summary from Studies (cont’d)

• There is no known threshold concentration below

which radon exposure presents no risk

• Even low concentrations of radon can result in a

small increase in the risk of lung cancer

• The majority of radon-induced lung cancers are

caused by low and moderate radon

concentrations rather than by high radon

concentrations

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Summary from Studies (cont’d)

• Numerous countries do regulate radon either on a

mandatory or advisory basis

• There is international shift towards stringent

approach to indoor radon regulation

• From the above conclusions, clearly regulatory

controls are necessary, however there are

challenges to overcome

• Planned Exposure Situations are already authorised

by the National Nuclear Regulator

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Countries Regulating Radon

Country Reference level (Existing

dwelling) in Bq.m-3

Reference level (New dwelling) in

Bq.m-3

Austria - 200

Belarus - 400

200

Czech Republic 500 -

Denmark - 200

Finland - 200

Germany - 250

Greece - 200

Poland 400 -

Russia 400 -

Slovenia 400 -

D. Sweden - 20

Switzerland 1000

400

-

A. USA 150 160 - 240 Bq.m-3 including

background

B. UK - 200 - 400 Bq.m-3

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Reference: Åkerblom G

Indoor Concern of Radon in RSA

• More than 100 years of gold mining in South Africa • Radioactivity contamination of land during early years of

mining due to lack of regulatory control • Continuous deposition of radioactive dust from Tailings

Storage Facilities (TSFs) • Tailings material run-off onto land occupied by the public

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Concern about Indoor Radon

• Mine waste readily accessible to the public and its possible use for construction (i.e. waste rock, tailings)

• Uranium prospecting and mining in the Karoo • Certain geological formation can give rise to excess risk

due to radon exposure (natural phenomena) e.g. Paarl in Western Cape Parts in Mpumalanga

• Resulting in possible exposure scenarios

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Dwellings Proximity to TSFs

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TSFs in Johannesburg

2001

2015

2010

Ref: Google Earth Images

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Uranium Ore used in Construction

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Typical Radon Exposure Situation

Scenario 1: House built using radioactive uranium

ore

• Beaufort West farm (Karoo) house foundation built

from abandoned uranium ore stockpiles

• Average concentration : 476 Bq.m-3 ~ 11.99 mSv/a

• Maximum value: 536 Bq.m-3 ~ 13.5 mSv/a

• Occupancy and habits dependent

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Typical Radon Exposure Situation

Scenario 2: Houses built on radon prone area

• Tshepisong Township in Soweto

• Average concentration : 211.9 Bq.m-3, ~ 5.32 mSv/a

• Highest value: 1728.5 Bq.m-3, ~ 43.5 mSv/a

• Occupancy

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Current National Situation

• Indoor radon exposure situations exist in South

Africa, and may be very extensive (to be confirmed by

studies)

• Not unique to South Africa (cases around the world)

• Current regulatory framework does not provide for

regulatory control of radon in dwellings

• Hence the NNR must advise government accordingly

on measures to be taken to assure protection of

persons

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Current National Situation (cont’d)

• It is appropriate for South Africa to include in its

regulatory framework existing exposures, including

indoor radon

Definition:

existing exposure situation means a situation of exposure that already

exists when a decision on the need for control needs to be taken. Existing

exposure situations include exposure to natural background radiation that is

amenable to control; exposure due to residual radioactive material that arose

from past practices that were never subject to regulatory control

Question: What reference levels of radon concentrations will be

introduced?

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Reference Levels (i)

Reference Level

(RL) as Radon

Concentration

Comments and Possible Actions

200 Bq.m-3

Lower bound

reference level

Radon concentration should be kept below 200 Bq.m-3

Existing houses should implement moderate and

inexpensive mitigation measures to reduce radon to

below 200 Bq.m-3 with measures such as

o Increase of ventilation in the house (more windows,

keep windows open, install airbricks, install simple

extraction fans, etc.)

All new houses including those in radon prone areas

should comply with radon levels below 200 Bq.m-3

o Ensure that building materials do not contain

elevated radium content leading to elevated radon

concentration

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Reference Levels (ii)

Reference Level

(RL) as Radon

Concentration

Comments and Possible Actions

300 Bq.m-3

Upper bound

reference level

• Reduce radon concentrations to below 300

Bq.m-3 and ensure optimisation

• Educate the public

• Install active radon reduction equipment

• Building pressurization

• Increase ventilation rate

• Increase natural ventilation (i.e. fit more

windows, open windows, install airbricks, etc.).

• Ensure that building materials for all new

dwellings is not contaminated with radium

• Prohibition of using mining waste for

construction

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Justification of the Approach

• Provide optimisation targets for various exposure

situations (lower and higher radon concentrations)

• Alignment to international recommendations

• Advisory approach, hence compliance with the RL should

be achievable without excessive cost

• There is no defined safe level (threshold) for radon, so

keep it as low as reasonably achievable (optimise)

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Anticipated Legislative Changes

• Currently the NNR Act and Regulations are being

revised to include existing exposures as well

• Indoor radon is included in the draft regulations

In future

• The NNR will advise government to include

mandatory radon measurements in housing

regulations and building codes

• Control must be at level of housing regulation

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Anticipated Legislative Changes

• It will be proposed for indoor radon to be controlled at

local government level

• Amendment of local government legislation will be

necessary to accommodate the change.

• Local government should require that radon

measurements are performed and should strictly

control the developments in areas classified as radon

prone and prevent the usage of contaminated

building materials for construction

• Introduction of Rn (222 and 220) to Exclusion Levels

applicability

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Existing Exposure Situations

• Reference Levels applicable to the representative

person in the range of 1 – 20 mSv (feasibility in

controlling the situation)

• Public Exposure Due to Indoor Radon (Draft

Regulations) – not exceed an average of 300 Bq.m-3

• Persons or organisations responsible for the

planning, implementation and verification of radon

protection measures shall ensure that:

– Priority to reduce radon activity concentrations of 222Rn shall be assigned

– Reduction to level at which is optimised

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Preparatory activities

• The general extent of indoor radon problem across the

country must be investigated to identify radon prone

areas. Investigations of certain areas will be prioritised.

• Implementation of controls will only be in areas

identified as radon prone areas

• Solicit funding for implementation of appropriate

corrective measures. i.e. government, other relevant

parties, etc.

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Preparatory activities

• Public education and communication programme must

be launched on the risk associated with radon

exposures in dwellings:

– To educate local government and its relevant

employees

– To get public support and buy-in (stakeholder

engagement)

– Improve on chances of success of the project

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Expected Challenges

The National Nuclear Regulator does not have

capacity to oversee the implementation of controls

for each affected household due to limited footprint:

• Large numbers expected, may be widespread

across the country

Households may not have sufficient funds to

implement the necessary corrective actions:

• Most houses likely to be affected are low cost

housing due to their proximity to mining areas.

• Owners unable to cover the costs

Government funding may be limited or deferred

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Way Forward

a) Propose a national study to identify radon prone

areas

b) Update legislation and regulations to include radon

in dwellings

c) Engage local government departments on

incorporation of radon in dwellings in their building

codes and its regulatory control

d) Educate the public on risks due to radon exposure

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Wilcot Speelman - Senior Specialist: Environment & Radiation Protection National Nuclear Regulator – South Africa Eco Glades 2 Block G, 420 Witch Hazel Avenue, Highveld, Centurion PO Box 7106 Centurion, 0046 c: +27 (0) 83 744 7492 - t: +27 (0) 12 674 7102 - f:+27 (0) 86 589 0368 e: wjspeelman@nnr.co.za I w: www.nnr.co.za

The End – Thank You