Aberdeen Beach radioactivity detailed information
SUMMARY of research investigations by Prof Stuart Haszeldine. Posted 27 April 2007
• Foot Dee beach contains pollution from Naturally Occurring Radioactive Material, originating from a discharge only tens of metres away.
• Levels of radioactivity in Foot Dee beach sand, are well above the levels at which regulators become involved.
• The radioactive material is much, much, less radioactive than fuel
particles at Sandside beach. But at Foot Dee there are many,
many, particles - so exposure to some additional radioactivity is guaranteed.
• If this sand were transported off the beach, it would be classed as Low Level Radioactive Waste.
• SEPA are uncertain how this radioactivity arrives at the beach, about
how much radioactive material is present on the beach, and about how it
• International standards recommend a very low radioactive dose to protect the public
• The dose calculated by SEPA exceeds the internationally recommended minimum by 16 times
• SEPA have not stated that there is no risk to the public at Foot Dee.
• This dose can be permitted by interpretation of UK law, but that is more lax than international recommended aspirations.
• SEPA calculations suggest a risk of death is 1 in 100,000 for an adult, exposed by being on the beach for many hours
• Children and infants could receive larger doses than
calculated by SEPA, by eating sand - just one sugar cube volume exceeds
• A remedy, in line with international recommendation, is to place information notices on the beach.
This can enable the public to adapt their behaviour and greatly reduce their personal risk.
• Foot Dee may be the most radioactive public beach in the UK.
• Foot Dee beach is much more radioactive than discharges from nuclear power plants.
Simpler introductory information is at http://www.geos.ed.ac.uk/homes/rsh/Aberdeen_Beach_radioactive.html
REPLIES TO COMMENTS RECEIVED
References at base of this page
1) The scale is significantly radioactive
The UK level for radioactivity of regulatory interest is 0.37 Bq/g for
solid material containing radium, and for several other radionuclides
(1). NORM (Naturally Occurring Radioactive Material) scale is
frequently at 40 Bq/g activity (2). The scale at Aberdeen beach
arises from decontamination of oilfield equipment by a company in
Aberdeen. It is my understanding that protective equipment is required
in those operations, and that a licence to discharge radioactive
material has been required. It is therefore apparent that this
scale is regarded by regulators as significantly radioactive.
2) This radioactivity emits alpha particles
It is a matter of record, in a report by the British Geological Survey
(3),that alpha and beta particles are detected in the scale, and in
samples of the beach sand.
3) these are 20 times more dangerous than beta particles
This is an accepted figure for the weighting factor of the absorbed
dose (4). Obviously, as explained elsewhere, that full dose requires
ingestion of some radioactive material.
4) it is probable, but has not been directly measured, that these
particles are 100 times more radioactive ( ... than Foot Dee beach sand
This is an arithmetic calculation, based on the measured activity of
the scale and the activity in samples of beach sand diluted by
5) typically for very low level radioactive waste taken to a
landfill licensed for radioactive disposal, costs can be £5,000 per
Cost estimates are derived from a UKAEA document (5).
6) references to a member of the public.
This person has submitted information which is publicly available on
the SEPA website (6). The calculations are self-evidently highly
plausible, irrespective of their authorship. The person has asked
to remain anonymous. I have no reason to doubt their competence
in the information they have provided.
7) OSPAR has not prohibited the operational discharge of radioactive material.
The OSPAR treaty (7) specifically includes NORM (Appendix 3).
There is a distinction in the treaty between material arising and
disposed of offshore, and material arising on land, even if derived
from offshore. The focus of the present discussion is on waste
material which has arisen onshore. The Radioactive Substances
Strategy of this treaty has an aim that the signatories (including the
UK) are committed to “the ultimate aim of concentrations in the
environment near background values for naturally occurring radioactive
substances”. The definition of discharges covered by OSPAR
includes “ offshore pipelines from which substances or energy reach the
maritime area". The UK has a DEFRA policy that OSPAR
“should be completed within the agreed timeframe”, which is stated to
be 2020 (8). OSPAR does not prohibit discharges to the sea, but
those must be rigorously monitored, and the aspiration is to reduce all
discharges to background levels.
8) Two references … 0.37 Bq/g for radium 226 …… minimum allowed radioactivity for alpha particles ….
It is agreed that the original wording of “safe lower limit for radium
226” does not communicate the intended information. This has been
altered to “radioactivity greater than 0.37 Bq/g for radium is
sufficiently high to become of interest to regulators, because of its
The original sentence “many samples of beach sand are 15 times more
radioactive than the minimum allowed radioactivity for alpha particles”
can potentially be read in different ways. For greater clarity
this is changed to “the maximum un-regulated level of radioactivity
allowed for radium (producing alpha particles) is exceeded by up to 15
times in many bulk samples of Foot Dee beach sand”.
It is also noted that the activity of Foot Dee beach sand places it
within the LLW (Low Level Waste) category, as alpha emitting material
is not included in the definition of VLLW for “dustbin disposal” to
landfill (9). Some public information is un-specific about this
distinction between alpha emitting and beta emitting waste. There
is even a suggestion (10) that double standards have evolved in Europe,
perhaps unintentionally, for NORM versus artificial radioactive
9) Several hundred tons of sand seem to be affected
The surface expression of enhanced radioactivity at Foot Dee is
elongate parallel to the sea defences, and located around the high tide
mark. This material constitutes several hundreds of tons of
sand. Suggestions that storm events may remove NORM can not be
supported either for, or against. At present there is (according
to SEPA (11)) a detectible quantity of fertilizer in this sand, which
is interpreted to originate from discharges from the industrial site
over 20 years ago. Therefore the existing evidence shows that
radioactive material (fertilizer) has persisted on this section of
beach for over 20 years, making it quite possible that NORM will remain
for a similar period. Additionally, there is a low barrier wall
running parallel to the sea defences, but often buried beneath sand
(18). This is considered to have potential to act as a trap for
mobile sediment. It is quite possible that the wall has enabled
hydrodynamic concentration of dense NORM radioactive scale material by
storm wave winnowing, and that radioactivity may increase landward of
the wall. This is the opposite of suggestions that storms will
remove the dense radioactive sand.
SEPA initially stated that radioactivity on the beach was due entirely
to previous discharges from fertilizer processing. However,
following new evidence submitted (6), SEPA have now agreed that
significant NORM occurs on Foot Dee beach (11)
10) Dispersion study
Tracer particles of similar size and density to NORM were released from
the discharge pipe on 13 April 2005, and samples from the beach were
collected during the following days, to identify if anyof this material
returned to the beach (19). The study does conclusively show that
sand-sized material, which is released from the discharge pipe, several
tens of metres from Foot Dee beach, can be transported to the beach
within a few days. This single study is not a good method to
quantitatively determine the overall motion of NORM particles during
the yearly wave and tide cycles. Although the general motion of
sand particles is supposed, historically, to be northwards along
Aberdeen beach, it remains un-clear at what rate this occurs, and what
pathway the sand takes. The uncertainty of sediment movement is
demonstrated by the erosion of Aberdeen beach in the past decades and
years. Dredging of harbours can often promote erosion of
nearby beaches - though that is speculation at Aberdeen.
11) Context and risk assessment
The risk from the radioactivity of beach sand is a matter for a
calculation of dose to a “critical group”. That involves exercise
of judgement as well as standard practise. The overall risk
appears to be lower than many common, but significantly dangerous,
activities like driving a car – such analogies are made to aid
However it cannot be said that there is no risk, and SEPA have
noticeably not made such a statement. The dose, and hence risk,
can be calculated by several exposure routes:
a) My own estimate of dose, and hence risk, was based on
extrapolation from (2), and produces a lower result for adults compared
to the more sophisticated calculations.
b) SEPA have calculated (12) a combination of individuals
residence time on the beach, with minor ingestion and inhalation.
This gives an adult dose to an individual of the critical group of 167
micro Sievert per year.
c) SEPA have also calculated a dose by ingestion (12). This
can result in a 1,000 micro Sievert (1 mSv) dose to a “critical group”
infant by eating 50g of sand. However it is unclear why a dose of 300
micro Sievert has not been chosen, as the dose constraint normally used as appropriate
for a single source of radioactivity – this would result from just 15g sand
ingestion. It is notable that declarations to OSPAR by UK
facilities take the more rigorous 300 micro Sievert as the appropriate
annual dose (13) rather than 1000 micro Sievert.
d) There are proposals to construct a landfill to dispose of this
NORM waste in future, instead of disposal into the nearshore
ocean. These proposals base their performance calculations of
safety on a dose target of 20 micro Sievert per year to an individual
e) The ALARA (As Low As Reasonably Achievable) principle has as its lower limit a dose of 20 micro
Sievert per year, and UK regulation has this as its ambition for
operational facilities (14, 15) by 2020. It is not clear why
international guidelines are not followed by SEPA to reduce public risk.
Expanding on the above:
ai) An estimate was made because the full calculation of dose is highly
complex, depending on the radionuclides and on the summation of
individual body organs. My estimate calculated that adult
ingestion of about 1cm3 of pure NORM would produce an additional dose
of 20 micro Sv, ie an additional risk of death of 1 in 1,000,000.
bi) This dose to the public is exceptionally high, when compared to a
compilation of doses to the public from UK radioactive sites reported
to OSPAR (13). Many doses from operational nuclear sites are 5 or
10 micro Sievert. A comparable dose to Foot Dee is only obtained
in the UK from Sellafield, and that exposure route envisages
substantial consumption of contaminated food. By contrast the
Foot Dee dose calculated by SEPA is involuntary, is received mainly by
simply being on the beach, and is located in a public and exceptionally
popular place. It seems possible that Foot Dee is the most
radioactive public beach in the UK.
ci) The ingestion exposure route is, to some extent, a matter of
behaviour judgement. There are standard typical habit data for
radiological assessment, which can aid or guide such
calculations. This exposure route is particularly relevant at
Foot Dee, as this is a beach which is close to a children’s playpark,
and a section of beach where children can and do dig in the sand.
Ingestion of 15g of sand during several beach visits is, in my opinion,
within the bounds of possibility. This exposure route therefore could
be given especial attention. To argue that only 5g or 10g may be
ingested misses the point that the principles of ALARA and BPM point
towards a high standard of protection for the public. This
exposure route can be greatly reduced by public information, so that
public know this particular sand contains unexpected particles.
di) There at present is no clear disposal route in the UK for NORM
waste derived from onshore operations, in spite of this problem being
known for many years. Special Precaution Burial appears now to be
the preferred route (15). It is noted that the design of such a
facility takes 20 micro Sievert as the reference of public dose for its
design (14). Obviously, this is not the same as guaranteeing that
levels of contamination will not exceed that limit. However the
same NORM material is present on Foot Dee beach in activities up to 6 Bq/g,
which could result in doses of 167 micro Sievert per year to
adults. This translates conventionally (16) into a 1 in 100,000
risk of death. This has been known since 2003. Because the NORM
has been “disposed of” by the site operator, this un-intended beach
accumulation has now become the disposal site for part of that
NORM. Because of the long half life for much of the radioactive
material, the beach activity will only decrease by natural sand
dispersion. However there is evidence that some radioactive
material has been present for over 20 years, so NORM could well remain concentrated on the beach for that timespan. Neither are the processes
of concentration of the waste understood by SEPA. It is quite
possible that this level of radioactivity will persist for many decades
into the future. Logically, equally high standards of public
protection should apply to this beach “disposal site” compared to a
landfill site. Similar public standards are not being
ei) The ALARA (As Low As Reasonably Achievable) principle means that
all reasonable steps should be taken to protect people, whilst also
weighing costs against benefit. The international Precautionary Principle notes
that lack of scientific certainty should not postpone cost-effective
Since 1954 the ICRP (International Commission on Radiological
Protection) has recommended that “every effort be made to reduce
exposures to all types of ionizing radiation to the lowest possible
level” (17). The ICRP recommend that additional dose to the
public be as low as 1,000, 300, 100 or 10 micro Sv, depending on
context. The maximum risk constraint from a single source is
recommended to be 10-5, ie 300 micro Sv (ref 17, p67). The ICRP
emphasise the need to justify and optimize the benefit to the public if
greater radiation doses to the public are anticipated, with a maximum
dose of 1,000 micro Sv (1 mSv/yr). This optimized reference level
should take account of all exposure routes to the public – for example
in the Grampian Region especially, the dose from radon in housing may
still be significant for some individuals. Consequently to adopt
1 mSv/yr as a reference level for Foot Dee alone is too simplistic.
Where the exposure is prolonged to long lived radionuclides in waste
disposal, the ICRP recommend a public exposure constraint of 300 micro
Sv /yr (ref 17, Table 8, p78) as the upper bound on the dose. If the
dose is uncertain or verification is uncertain, the dose constraint
could be as low as 100 micro Sv/yr (ref 17, para 253, p65). Where
individuals are exposed to a dose from which there is no societal
benefit, then the ICRP recommendation is that dose should be less than
0.01mSv/yr, ie 10 micro Sv (17 para 232, and Table 5).
“exposure of members of the public from the planned operation of
practices is a prime example of this type of situation”. The
maximum dose calculated by SEPA is less than 300 micro Sv, but more
than 100 micro Sv. Given the uncertainty in knowledge of the
transport of particles, uncertainty in knowledge of physical
concentration, and the knowledge the natural processes of particle
dispersion are slow, my opinion is that the lowest ICRP limit should be
It is noted in the calculations (a, ai; b, bi and c, ci above) that
these exposure routes depend on the behaviour of people. A low
cost intervention, consistent with ALARA, could be to provide people
with information, and then individual choices can be made to modify
behaviour. In the particular circumstance of Foot Dee, one or
more information notices could cheaply and easily provide public
information that this section of beach is contaminated, whereas the
sections of beach in the intertidal zone, and northwards beneath the
Esplanade, are not significantly contaminated. To avoid ingestion and other
exposure routes the public, particularly children, could be recommended
to not handle Foot Dee sand or habitually spend long periods on that
section of beach.
12) Additional facts
• NORM discharge assessments and risk: As explained in point 11,
although these risks are low, it is not agreed that these risks are
• No breaches to disposal licence; That is not the concern
• No alternative disposal options: That is not the concern.
• Industry NORM management plan: The past, existing, and future
contamination of Foot Dee beach will remain an issue of public exposure
long after the oil industry has moved to less polluting methods.
There is good evidence that significantly radioactive scale particles
occur commonly on Foot Dee beach. These produce a 6Bq/g activity of bulk beach
sand, which is well above the 0.37 Bq/g limit of radiation for
regulatory interest. There is a poor understanding of the
concentration, and future duration of contamination. SEPA have chosen
1000 microSv/yr as their dose maximum, rather than a maximum dose from
a single source of 100-300 microSv/yr. Where societal benefit is
minimal, international standards recommend a dose reference level of 10
microSv/yr, and 20 microSv/yr is now being used to plan disposal
facilities for the same NORM waste in landfill (14). SEPA calculate
feasible exposure routes at Foot Dee which produce 167 microSv/yr doses
to adult public; children and infants could receive greater doses from
ingested material. This exceeds international recommendations for
a dose where there is no benefit to the exposed population. This
dose conventionally translated into risk of death or cancer is 1 in
100,000 of the population with that exposure route. This is at
the maximum dose limit recommended internationally for the
public. A simple remedy, aligned with the precautionary
principle, is to erect explanatory or information notices, so that public
can modify their behaviour and so eliminate the worst exposure routes.
Disagreement remains about such a simple intervention, with SEPA
refusing to recommend it.
1 Radioactive Substances Act 1993
2 NORM in the oil and gas industries. National Radiological Protection
Board information sheet 1999 http://www.hpa.org.uk/radiation/
3 Mineralogical and geochemical characterization of beach sand and
scale samples for SEPA. British Geological Survey CR/05/207
Available from SEPA
4 eg p 43 http://www.sepa.org.uk/pdf/radioactivity/prospective_public_dose.pdf
5 Establishing dialogue and sustainable practices G. Linekar, UKAEA
6 Letter from consultees in consultation SEPA 2006
8 DEFRA aspirations for OSPAR
9 CoRWM 2006
Also for example DEFRA 2005 Disposal Of Low Level Radioactive Waste
From Non-Nuclear Premises
Recycling and NORM. World nuclear association 2004
11 SEPA 2006 Response to consultees comments Page 5 “Having reviewed
the content of the new assessment of the data SEPA now accepts that, on
the basis of the assumptions made, minerals associated with oilfield
scale appear to contribute to a greater proportion of the radioactivity
on the beach than minerals associated with fertilizer production.”
12 SEPA Sept 2005
Summary of updated dose assessment for Aberdeen Beach.
Obtained from SEPA
13 OSPAR Commission 2005 The Application of BAT in UK Nuclear
14 SNIFFER 2005 Project UKRSR03 pp 10-11 The development of
a framework for assessing the suitability of controlled landfills to
accept disposals of solid low-level radioactive waste:
15 DEFRA 2007 Policy for the Long Term Management of Solid Low Level
Radioactive Waste in the United Kingdom.
16 Radiation effects at low doses Lawrence Livermore 2000
18 Radioactive Contamination on Aberdeen Beach: B Tilly and A Hills
Available from SEPA
19 Scotoil outfall dispersion study, Aberdeen. Report
05/J/1/12/0731 Sept 2005
Available from SEPA