Commission Recommendation of 20 December 2001 on the protection of the public against exposure to radon in drinking water supplies (notified under document number C(2001) 4580)
Date: 2001-12-20
Institutions: European Commission
Subjects: consumer protection, drinking water, rare gas, water pollution

28.12.2001

EN

Official Journal of the European Communities

L 344/85

COMMISSION

COMMISSION RECOMMENDATION

of 20 December 2001

on the protection of the public against exposure to radon in drinking water supplies

(notified under document number C(2001) 4580)

(2001/928/Euratom)

THE COMMISSION OF THE EUROPEAN COMMUNITIES,

approach is
Directive 96/29/Euratom.

in accordance with Article 6(3)(a) of

Having regard to the Treaty establishing the European Atomic
Energy Community, and in particular Article 30, the second
paragraph of Article 33, the first paragraph of Article 38, and
the second indent of Article 124 thereof,

Having regard to the opinion of
the Group of Experts
appointed by the Scientific and Technical Committee pursuant
to Article 31 of the Treaty,

Whereas:

(1)

(2)

Council Directive 96/29/Euratom of 13 May 1996
laying down basic safety standards for the protection of
the health of workers and the general public against the
dangers arising from ionising radiation (1) lays down a
framework for controlling exposures to natural radiation
sources arising from work activities. Title VII of the
Directive applies to work activities within which the
presence of natural radiation sources leads to a signifi-
cant increase in the exposure of workers or of members
of the public. Member States are required to identify
work activities which may be of concern.

In view of
the large geographical variability in the
natural occurrence of radon and in the extent to which
the population and water supplies are affected, a flexible
approach is needed to allow Member States to apply the
concept of optimisation, while ensuring protection of
the most highly exposed part of the population. Such an

(1) OJ L 159, 29.6.1996, p. 1.

(3)

(4)

(5)

(6)

The Group of Experts set up under Article 31 of the
Euratom Treaty has provided technical guidance (2) for
the implementation of Title VII of Directive 96/29/
Euratom (1). The guidance includes the protection of
workers to inhaled radon in establishments where signif-
icant amounts of radon may be released from water into
indoor air.

Commission Recommendation 90/143/Euratom of 21
February 1990 on the protection of the public against
indoor exposure to radon (3) introduces reference and
design levels for indoor radon. The reference level for
consideration of remedial action is 400 Bq/m3 and the
design level for future constructions is 200 Bq/m3.

Surveys in Member States have shown elevated concen-
trations of radon in some ground waters, particularly in
regions with crystalline rocks. There are circumstances
under which radon concentrations in drinking water are
radiologically significant as they expose the population
to enhanced doses and should not be disregarded from
the radiation-protection point of view. High concentra-
tions are often related to individual drilled wells, but
sometimes also to waterworks utilising rock or soil aqui-
fers.

In many Member States there is increasing awareness of
the significance of exposure of the population to radon
in drinking water. Several countries have already or are
drawing up dose-control policies.
In many cases the
control policies are drawn up in accordance with the
protection principles established by the Council Direct-
ives 96/29/Euratom and 98/83/EC of 3 November 1998
on the quality of water intended for human consump-
tion (4).

(2) Radiation Protection 88. Recommendations for the implementation
of Title VII of the European Basic Safety Standards Directive (BSS)
concerning the significant increase in exposure due to natural radia-
tion sources. European Commission, Luxembourg, 1997.

(3) OJ L 80, 27.3.1990, p. 26.
(4) OJ L 330, 5.12.1998, p. 32.

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(7)

(8)

(9)

(10)

Radon is a naturally occurring radioactive noble gas, the
most significant isotope of which is radon-222 with a
half life of 3,82 days. This isotope is a member of the
uranium-238 decay series and its presence in the envir-
onment is associated mainly with the trace amounts of
in rocks and soil.
its immediate parent, radium-226,
Because radon is an inert gas, it can move rather freely
through porous media such as soil or fragmented rock.
Where the pores are saturated with water, as in soil and
rock under the water table, radon is dissolved into the
water and is then transported by it. Water-saturated soil
with a porosity of 20 % and a radium concentration of
40 Bq/kg, which is the world-wide average in the earth's
crust, causes at equilibrium a radon concentration in
ground water of the order of 50 Bq/l.

to 50 000 Bq/l

Surveys in Member States have shown that
radon
concentrations in surface waters are very low, usually
well below 1 Bq/l. Concentrations in ground water vary
from 1 to 50 Bq/l
for rock aquifers in sedimentary
rocks, to 10 to 300 Bq/l for wells dug in soil, and to
100 Bq/l
in crystalline rocks. The
highest concentrations are usually associated with high
uranium concentrations in the bedrock. A characteristic
of radon concentrations in rock aquifers are their vari-
ability; within a region with fairly uniform rock types
some wells exhibit concentrations far above the average
for that region. Significant seasonal variations in concen-
trations have also been observed.

supplies

Radon in domestic water
causes human
exposure through ingestion and inhalation pathways.
Radon can be ingested by direct consumption of tap or
fresh bottled water. Radon is released from tap water
into indoor air which causes exposure to radon by inha-
lation.

the United Nations Scientific
In its report of 1993,
Committee on the
Effects of Atomic Radiation
(UNSCEAR) (5) estimated that the committed effective
dose from ingestion of radon in water is 10−8 Sv/Bq for
an adult and somewhat higher for a child and an infant.
In 1998, the National Research Council, a committee in
the United States, presented a conversion factor of
0.35.10−8 Sv/Bq (6). The committee did not find suffi-
cient scientific evidence to introduce separate dose esti-
In addition to the
mations for different age groups.
conversion factor, the ingestion dose depends also on
the annual consumption of water. Estimates on the

(5) UNSCEAR 1993 report. Sources and effects of

ionising radiation.
United Nations Scientific Committee on the Effects of Atomic
Radiation, New York, 1993.

(6) Risk Assessment of Radon in Drinking Water. Committee on Risk
Assessment of Exposure to Radon in Drinking Water, Board on
Radiation Effects Research, Commission of Life Sciences, NRC
(National Research Council). National Academy Press, Washington
DC, 1999.

(11)

(12)

(13)

(14)

annual committed effective dose absorbed by an adult
by the ingestion of water containing 1 000 Bq/l vary
between 0,2 mSv and 1,8 mSv, depending on the
annual water consumption and the range of conversion
factors used.

The increase in indoor radon concentration caused by
tap water depends on various parameters such as the
total consumption of water in the house, the volume of
the house and the ventilation rate. Both the UNSCEAR
and the National Research Council
that
1 000 Bq/l of radon in tap water will on the average
increase
radon concentration by
100 Bq/m3.

estimate

indoor

the

air

Radon in drinking water is controllable in the physical
and engineering sense; effective methods for removing
radon from drinking water have been developed (7) and
are commercially available. Accordingly, an appropriate
system needs to be established for reducing significant
exposures. An important part of the system is the adop-
tion of reference levels for consideration of remedial or
preventive action.

The methods and equipment used for removing radon
and long-lived radon decay products from water do not
significantly differ in techniques or in costs between an
existing water supply and a new supply planned for
future use. Consequently, the same criteria, including the
reference levels, may be used for remedial action on the
existing water
setting preventive
requirements for new water supplies.

supplies and for

For an individual water supply, whereby no water is
supplied as part of a commercial or public activity, the
exposure caused by radon in water is a phenomenon
fairly similar to that of radon in dwellings. Accordingly,
similar radiological protection criteria should be applied.
Considering both the ingestion and inhalation pathways,
the annual effective dose caused by water containing
1 000 Bq/l radon is, according to current knowledge,
very comparable to that caused by an indoor radon
concentration of 200 Bq/m3, the design level established
in Recommendation 90/143/Euratom.

(15) Where water is supplied as part of a commercial or
the
public activity, such as through a waterworks,
consumer does not have the same opportunity to
control the received dose as an owner of an individual
supply. It follows that the consumer must be confident
that the water does not pose any risk to human health.
In addition, remedial action taken on that water affects a
large number of people, which makes the action more
cost-effective at lower radon concentrations than is the
case with an individual supply. Consequently, it is justi-
fied to adopt a more stringent control policy, including a
lower reference level, for water supplied as part of a
commercial or public activity than for an individual
supply. Small amounts of radon in water are ubiquitous

(7) The Commission has funded and is funding several research projects
on the risk of exposure to radon. The TENEWA project (Treatment
Techniques
from Drinking
Water) carried out under the CEC contract No FI4PCT960054 has
produced a significant amount of information on the removal tech-
niques,
including information on the possible radiological hazards
caused by removal devices.

for Removing Natural Radionuclides

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and therefore no remedial action should be required if
the concentration is less than 100 Bq/l. National surveys
might show that a higher reference level needs to be
adopted for implementing a practical radon programme.
However,
is unlikely that public or commercial
distribution water with a radon concentration exceeding
1 000 Bq/l could be considered justifiable from the
radiation protection point of view.

it

(16)

The radon concentration of water at
the point of
delivery is unlikely to be greater than that at the source,
as in the case of a waterworks. Usually a measurement
at the source is sufficient to demonstrate compliance
with the reference concentration and no separate meas-
urements are needed at
the various points of use.
However, the radioactive decay and possible aeration of
radon during delivery may need to be taken into
account, for example,

in assessing the doses.

(17) Directive 98/83/EC requires

are

circumstances

the Member States

to
monitor the concentrations of natural radionuclides in
drinking water, but in addition to radon, radon decay
the
products are also excluded from the scope of
Directive. There
under which
polonium-210 and lead-210 (long-lived decay products
of radon)
in drinking water pose a comparable or a
higher radiation risk than some natural radionuclides
monitored in accordance with the Directive. Accord-
ingly, polonium-210 and lead-210 should not be disre-
garded in monitoring and in taking action to reduce
exposures caused by natural radionuclides in drinking
water. Reference concentrations for polonium-210 and
lead-210 should be established and they should be
monitored according to the principles set for natural
radionuclides by the Directive. The indicative dose of
0,1 mSv and the principles of dose calculation estab-
lished in the Directive should be used for deriving the
reference concentrations.

(18) High radon concentrations indicate a potential presence
of other radionuclides of the uranium decay series in the
water, although the correlation is not always unambig-
uous. When remedial action is taken to reduce radon
concentration, the presence of other natural radionu-
clides should be screened and, where appropriate, be
analysed in more detail so that a suitable technique can
be chosen to remove all the radiologically significant
natural radionuclides from the water at the same time, in
a cost effective way.

(19)

Specific guidance should be made available to the water-
works and to the owners of public water supplies on the
different methods available for removing radon and
from water. The
long-lived radon decay products

guidance should include, in particular, instructions on
the handling and disposal of accrued radioactive waste
and on the ways of minimising possible exposure due to
radon released from a removal device or by the increase
in external gamma radiation in the vicinity of a removal
device.

(20)

Simple metrological procedures should be established to
ensure that measurements of radon and radon decay
products in water yield data of the appropriate quality
and reliability.

(21) Owing to the special characteristics of

the problem,
adequate public information is an important element
both in improving the controllability of exposure and in
securing a positive public response.

(22)

this Recommendation is to provide
The purpose of
guidance to the Member States for setting controls on
exposures caused by radon and radon decay products in
drinking water,

HEREBY RECOMMENDS:

1. This Recommendation concerns the radiological quality of
drinking water supplies regarding radon and long-lived
radon decay products.

2. An appropriate system should be established for reducing
exposures to radon and long-lived radon decay products in
domestic drinking water supplies. Within this system
adequate public information and response to public
concern deserve particular attention. Under the system
attention should concentrate on the highest exposures and
on those areas where action is most likely to be effective.

3. For the purpose of this Recommendation, ‘drinking water’

shall mean:

(a) all water either in its original state or after treatment,
intended for drinking, cooking, food preparation or
other domestic purposes, regardless of its origin and
whether it is supplied from a distribution network,
from a tanker, or in bottles or containers,

(b) all water used in any food-production undertaking for
the manufacture, processing, preservation or marketing
of products or
intended for human
consumption unless the competent national authorities
are satisfied that the quality of the water cannot affect
the wholesomeness of
in its finished
form.

the foodstuff

substances

Natural mineral waters covered by Council Directive 80/
777/EEC (8) and waters which are medical products
according to Council Directive 65/65/EEC (9) are excluded
from the scope of this Recommendation, since special
rules for those types of water have been established.

(8) OJ L 229, 30.8.1980, p. 1.
(9) OJ Special Edition 1965–1966, p. 20.

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4. Representative surveys should be undertaken to determine
the scale and nature of exposures caused by radon and
long-lived radon decay products in domestic drinking
water supplies originating from different types of ground
water sources and wells in different geological areas unless
this information is already available. The surveys should be
designed in such a way that underlying parameters, and
especially the geology and hydrology of the area, radioac-
tivity of rock or soil, and well type, can be identified and
used later for directing further action on the highest expos-
ures. The surveys should cover,
(a) drilled wells, especially those in crystalline rock areas,
(b) waterworks using rock or soil aquifers.

in particular:

5. For water supplied as part of a commercial or public

activity, the following action should be taken:
(a) above a concentration of 100 Bq/l, Member States
should set a reference level for radon to be used for
consideration whether remedial action is needed to
protect human health. A level higher than 100 Bq/l
may be adopted if national surveys show that this is
radon
a
necessary
programme.
of
concentrations
1 000 Bq/l, remedial action is deemed to be justified
on radiological protection grounds;

practical
in

implementing

excess

For

for

(b) measurements of

radon concentration should be
required if there is a specific reason to suspect, on the
basis of the results of representative surveys or other
reliable information, that the reference level might be
exceeded;

(c) where significant concentrations of polonium-210 and
lead-210 are suspected, on the basis of the results of
representative surveys or other reliable information,
monitoring of these nuclides should be arranged in
conjunction with the monitoring of other natural
radionuclides required by Directive 98/83/EC;
(d) above a reference concentration of 0,1 Bq/l

for
polonium-210 and 0,2 Bq/l for lead-210, considera-
tion should be given to whether remedial action is
needed to protect human health.

6. For an individual water supply, from which no water is
supplied as part of any commercial or public activity, the
following action should be taken:
(a) a level of 1 000 Bq/l should be used for consideration

of remedial action;

(b) the urgency of the remedial action should be commen-
surate with the extent to which the reference concen-
tration is exceeded;

(c) where remedial action is considered necessary because
the levels of other natural radionuclides
of radon,
should be screened and where appropriate as a result
of the screening, other natural radionuclides should be

analysed and removed from the drinking water with
the same remedial action;

(d) where remedial action is considered necessary,

the
consumers concerned should be informed of the radon
levels of the water and of the remedies available to
reduce such levels.

7. Where measurements indicate that the radon in tap water
contributes significantly to exceeding the threshold set for
indoor radon, remedial action on this source should be
considered.

8. Drinking water distributed in public premises such as resi-
dential homes, schools, and hospitals should comply with
the principles of point 5.

9. Measurements should be made with appropriate methods
and equipment which have undergone approved calibra-
tion and quality assurance programmes.

10. Member States

should provide guidance on different
methods available for removing radon and long-lived
radon decay products from water. Member States should
provide instructions on the handling and disposal of radio-
active waste generated by the removal process and on
ways to minimise possible exposure caused by radon
released from a removal device or by the increase in
external gamma radiation in the vicinity of a removal
device.

11. The exposure of workers to inhaled radon in establish-
ments where significant amounts of radon may be released
from water into indoor air, in particular in waterworks,
spas and swimming pools, should be controlled according
to Title VII of the Directive 96/29/Euratom and according
to the Recommendations, ‘Radiation Protection 88’, made
in 1997 for the implementation of that Title by the Group
of Experts established under Article 31 of the Euratom
Treaty.

12. Member States should consider to what extent the inten-
tional use of radon-bearing water for its prospective thera-
peutic effects is justified by its economic, social or other
it may
benefits when set against
cause.

the health detriment

This Recommendation is addressed to the Member States.

Done at Brussels, 20 December 2001.

For the Commission

Margot WALLSTRÖM

Member of the Commission