Radiological protection of the environment
Andrew Miller MP was asked by the OECD to speak on the political imperatives at the conference “Radiological protection of the environment” 12th-14th
February 2002 in Sicily. The paper sets out some of the problems in improving public understanding of the complex issues, using some examples of man made and natural sources.
POLITICAL IMPERATIVES
Introduction
If you ask people about sunbathing on the beach, flying across the Atlantic or using their microwave, the word radiation is unlikely to be included in
their response. Of those examples the most probable dangers uppermost in the public’s mind are getting burnt on the beach, falling out of the sky, or salmonella from
undercooked food. On the other hand Three Mile Island or Chernobyl create a different response. These are human responses that one sees in other
areas of risk. Compare for example death on the road with aircraft crashes. When the latter occurs there are major enquiries that hit the headlines for
several days, whilst in Europe the tens of thousands of people dying on our roads rarely justify a mention because, by and large, they occur in ones and twos at a time.
So, the 2,000 people a year who die from skin cancer in the UK, largely from over-exposure to the sun, are barely mentioned because they are again individual cases. It is
far too simple to either blame the media or ignorance of science, but we need to examine carefully how relative risk is communicated to those potentially at risk.
Let us look at some examples:
Radon
The natural radioactive gas radon occurs in varying concentrations in all homes and workplaces. Inhaling radon causes the sensitive
cells of the lungs to be irradiated. Under most circumstances the risk is small but nevertheless, living for a lifetime in a house where radon is at the Action Level of
200 Bq m–3 carries about a 3% risk of fatal lung cancer (a quarter to a half of all such deaths are in non-smokers). It is estimated to be the second leading
cause of lung cancer after cigarette smoking.
In both of these maps one can see the need for
action in the field of construction, but I doubt that more than one or two percent of the population would use this data as a basis for determining where they should live.
Yet if one looks at some of the research perhaps a different conclusion may be justified.I want to draw on the work of the Radiological Protection Institute of Ireland
to illustrate my point.On 26 July 2001, RPII[i][i] announced “Within coming weeks the Radiological Protection Institute of Ireland (RPII) is
to launch a new campaign focusing on the hazards associated with radon gas in workplaces in High Radon Areas. The campaign will give effect to new legislation, implementing
an EU Directive on radiation safety, under which employers may be required to measure the radon concentration in a workplace. The campaign is to begin with a pilot
programme centred on Ennis, Co. Clare. Over the next month the RPII will be writing to all of the 1500 workplaces in the Ennis area. Employers will be
given information on radon and directed to have radon measurements made in their workplaces within a six-month period. These measurements can be made relatively easily and
inexpensively.”This is typical of the work that is going on throughout Europe but at a political level it is not what attracts the attention of our
Parliaments.In Ireland it is far more likely to be Sellafield that hits the headlines. And yet a paper published last year by the RPII[ii][ii]
said“The Radiological Protection Institute of Ireland (RPII) accepts the finding of a recent study, that a cluster of Down’s syndrome births in Ireland in the 1960s
and early 70s was not linked to Sellafield. The study¹, carried out by an international group of scientists led by an Irish epidemiologist, Dr Geoffrey Dean, was reported
in a UK medical journal last December. It investigated a suspected link between a serious fire in a nuclear reactor at Sellafield (then called Windscale) in
1957,”I am not seeking to brush aside the arguments in Ireland about Sellafield, I am merely trying to put it into perspective. Again the
RPII[iii][iii]are helpful here in a comment dated 5th October 2000. It says, “The radiation dose to Irish people due to
Sellafield fell slightly in 1999, continuing the slowly declining trend of recent years. This is one of the main findings of a new report on radioactivity levels in the
Irish marine environment in 1998 and 1999, which is published today by the Radiological Protection Institute of Ireland. The consumption of fish and shellfish is the
main pathway through which the Irish public are exposed to radiation as a result of discharges from Sellafield. The doses received via this pathway, at 1.4 microsieverts in
1998 and 1.3 microsieverts in 1999, are a very small fraction of the dose of approximately 3000 microsieverts received by the average person in Ireland each year from all sources of
radiation.”Surely therefore inhalation of radon should be a higher concern than the risk of eating prawns from the Irish Sea.
Flying
My second example is related to flying. All of us have been on a
plane and have been nervous at take off or landing, but has anyone ever heard a nervous passenger ask the steward about the radiation dose they are about to receive?A
paper, “Assessing Exposure to Cosmic Radiation during Long-haul Flights[i][i][iv]”, says:“The assessment of exposure to cosmic radiation on board aircraft is one of the concerns
of organizations responsible for radiation protection. Cosmic-particle flux increases with altitude and latitude and depends on solar activity. To
illustrate the effect of these parameters, exposure has been estimated on several airlines operating subsonic and supersonic aircraft on transatlantic, Siberian and transequatorial
routes. Measurements have been made with a tissue-equivalent proportional counter using the microdosimetric technique. This type of system provides the
absorbed dose, the ambient dose equivalent, the mean quality factor, and the dose distribution as a function of lineal energy. Data were collected at maximum solar activity
in 1991–1992 and at minimum activity in 1996–1998. The lowest mean dose rate measured was 3 Sv h–1 during a
Paris–Buenos Aires flight in 1991. The highest rates were 6.6 Sv h–1 during a Paris–Tokyo flight on a Siberian route
and 9.7 Sv h–1 on Concorde in 1996–1997. The mean quality factor is around 1.8. The corresponding
annual effective dose, based on 700 h of flight for subsonic aircraft and 300 h for Concorde, can be estimated at between 2 mSv for the least-exposed routes and 5 mSv for the more-exposed
routes.”
As I understand the current position, the ICRP “does not consider it necessary to treat the exposure of business passengers as
occupational exposure. The principal occupational group exposed to elevated levels of cosmic rays is aircrew. The exposure of jet aircrew should be treated as occupational exposure. The annual effective doses should be derived from the flying time and
typical effective-dose rates for the relevant routes. Since there are no other practical control measures, there is no need to consider the use of designated
areas. It is likely that the existing restrictions on the flying time of aircrew will provide sufficient control of exposures. Pregnant members of
aircrew are usually relieved of flying duties well before the end of pregnancy. The Commission sees no reason to invoke further protective measures for the
conceptus.”
But once again we have an example that shows the dramatic i.e. the plane crash has a greater resonance with the public rather than the continued albeit
small risk of the radiation dose.
Similarly doses from nuclear power plants are a cause of much greater public concern than risks from frequent flying.
Mobile telephony
The third area I want to examine is that of mobile telephony.
Half of the UK has mobile phones but there is an argument about the placement of every mast.
Although some campaigns are legitimate because of impact on visual amenity they are often associated with claims of health risk to the surrounding population.
If we look at the facts from the individual point of view of the individual user, one would have thought that the heating of the brain might cause greater
concern than the growth of the industry indicates.
Complex terminology such as SAR might cause worries.
Pictures of heated brains might cause even more panic, even though we are only talking about
.1°C.
This again illustrates the way in which the human response to the radiation levels is very much driven by the concerns over the large-scale
development rather than the impact on the individual. The typical response, however ill founded, is about the mast being too close to a child’s school rather than the
parents desire to own and use mobile phones.
The way
forward
We will never arrive at a point where all decision makers, whether they are parents or Prime Ministers, fully understand all the scientific issues
surrounding the key decisions that are needed.
And yet everyone makes decisions about risk many times each day.
Some risk assessment is at the subconscious level such as judgements about crossing the road.
We receive basic training from parents and teachers but so much of the decision to cross is based upon a complex judgement relating to speed and distance.
The formula is complex but we all do it regularly .
Some are much more conscious, like smoking or participating in dangerous sports. We know about the risk, yet many are prepared to take
it. Perhaps the common factor is that we make an assessment of relative risk and that this is the best way to help people deal with radiation risk. I
think Vodaphone present this in a sensible manner:
They help us gauge the relative risk from big things like masts and pylons by comparing them with commonplace items around the home.
The public understanding of science is best achieved by openness and honesty. In previous years all nations have been guilty of avoiding
these principles. That was understandable as many developments particularly relating to radiation were classified for obvious reasons.
Radiation information relating to depleted uranium shells is in the public domain. Whilst there is a lot of controversy about the causes
of, for example Gulf War illnesses (and frankly I doubt there is any general connection with DU), the nature of the ordnance used is well known. The open nature of the
debate is quite new and very different to similar arguments from previous conflicts and weapons testing.
In being open it is also important to avoid scaremongering. Let me be clear, I am not going to stop going into the sun whilst on holiday
in Cornwall, neither am I going to travel the world avoiding heights over 20,000 feet. But at the same time we need to encourage considered and sensible judgements,
just like those we use when crossing the road.
To enable people to make sensible judgements we have to de-mystify the language of both scientists and politicians. We also have to
avoid confusion caused by different standards that have been used in various countries – in other words use debates like this to try and ensure that common standards are
used. And finally, using concepts such as relative risk, help overcome very natural fears that surround radiation concerns.
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