ALARA - UK union pronouncement on worker radiation risk

["Franta, Jaroslav" <frantaj@aecl.ca>]

...this seems to fit the on-going ALARA thread:

http://www.newscientist.com/letters/letters_22339.html
High risk jobs
IN the issue of "Inside Science" on radiation and risk (18 March), you make
the statement: "Workers choose to risk exposure, whereas the public is
likely to be exposed unwittingly or unknowingly." 
The idea that workers are sufficiently empowered to make decisions on the
risk they face is a dangerous one. It is managers who control the processes,
and managers who carry out risk assessments. Workers are rarely given
sufficient information about the hazards they face or the consequences of
exposure. Even when they are informed, what choice do they have but to
accept the risk or leave their job?
The public sector union UNISON has argued for years that the levels of
radiation exposure deemed acceptable for workers in this country are far too
high. 
There is no "safe" level, yet the European Union's recommended maximum dose
for workers in any one year is 50 times that for the public, and even that
is often exceeded.
Hugh Robertson 
London 
UNISON

...the 18 March article included the following (note item on Roger Clarke,
the chairman of ICRP, near bottom):

http://www.newscientist.com/archive/archive.jsp?id=22306900
<SNIP>
Clearly, no practice involving exposure to radiation should be adopted
unless it produces a net benefit to those exposed or to society as a whole.
This is the principle of "justification". Even then, radiation doses and
risks should be kept as low as possible, taking economic and social factors
into account. This conclusion follows from the linear, no-threshold
assumption and has resulted in huge efforts to reduce doses to patients,
workers and the general public.
It is considered unacceptable to expose someone to a high risk of death,
even if society would benefit. Just what should the limit be? Two bodies in
Britain have attempted to quantify "acceptable" risk: the Royal Society,
reporting in 1983, and the Health and Safety Executive-the government's main
health and safety organisation-in 1988 and 1992.
Workers choose to risk exposure, whereas the public is likely to be exposed
unwillingly or unknowingly. So the studies looked at the different attitudes
in each case, comparing the risks from radiation with commonly accepted
risks such as those from driving a car.
For workers, the Health and Safety Executive recommends a dose limit of 20
mSv in a year, equivalent to an annual risk of death due to irradiation of 1
in 1000. The public dose limit is 1 mSv in a year, equivalent to a risk of
fatal cancer of 1 in 20 000. The ICRP says a higher dose is acceptable in
some years, providing the average over 5 years does not exceed 1 mSv a year.
Most developed countries have enshrined these principles of radiation
protection in law.
<SNIP>
Radioactive materials, especially potassium-40, are particularly
concentrated in some foods, so people who eat a lot of these foods can
receive doses well above the average. The main culprit is shellfish: eating
an 80-gram jar of mussels every week would add about 50 per cent to your
dietary dose in Britain.
Finally, uranium and thorium in rocks and soil decay to form the radioactive
gas radon. Radon leaks into the atmosphere where people inhale it and its
decay products, irradiating their lungs. Outdoors the gas disperses, but in
buildings high concentrations can build up. Studies from Britain and Sweden
have shown a link between radon in houses and death from lung cancer.
The radon risk depends on local geology, weather and ventilation, but its
concentration tends to be higher in houses built on granite, limestone and
alum shale, especially if these materials are also used in construction. The
global average annual dose due to radon is 1.3 mSv, but the highest dose
ever recorded was nearly a hundred thousand times greater. In one house in
Pennsylvania, residents received lung doses of 91 Sv a year, with a risk of
fatal cancer of about 13 in 100 a year. This frighteningly high
concentration was discovered when the occupant triggered the alarm bells at
the nuclear power station where he worked-as he was entering the site.
<SNIP>
Fortunately, there's an easy way to get rid of radon: a fan under the floor
can blow it out through a pipe before it enters a building. Compared with
all the natural sources of radiation, artificial sources, such as discharges
from nuclear and conventional power stations, give people much lower doses.
Fallout from nuclear weapons and reactors is less of a problem than it once
was. More than 500 atmospheric nuclear tests were conducted in the 1950s and
1960s, but the consequent doses to people peaked in the early 1960s and are
now much lower: in Britain, the yearly doses have fallen from 0.140 mSv in
1963 to 0.004 mSv now.
Meanwhile, the US is spending billions of dollars to clean up areas
contaminated by its ground-based nuclear testing programme of the 1940s and
1950s. This expense is one reason to question the linear, no-threshold
assumption. If the cancer risk to individuals from very low doses is zero,
or much smaller than the linear assumption implies, then there is little
point in spending vast sums to clean these areas up because even the total
risk to the populace will be low. The money could be better spent elsewhere.
<SNIP>
What of the future? The linear, no-threshold assumption has meant heavy
expenditure to reduce some very small doses. Roger Clarke, the chairman of
ICRP, believes that greater efforts should be made to reduce the more
significant doses, especially to patients and workers. The emphasis should
be on the individual: if the risk of harm to the health of the most exposed
person is negligible, then the total risk should be considered negligible,
no matter how many people are exposed.

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