91av

A RADICAL overhaul of the international safety regime governing radiation
would give the nuclear industry a licence to pollute the seas and air, warn
scientists. It might mean a worldwide rise in cancers in the long term.

The International Commission on Radiological Protection (ICRP), the world
advisory body based in Stockholm, Sweden, wants to make big changes to the way
safety levels are decided for people exposed to radiation from nuclear plants,
industrial sources and medical X-rays. But its plans, outlined for the first
time last week, have already fallen foul of experts who see no reason to change
the system agreed in 1990.

That system relies on measuring the “collective dose” of radiation received
by large populations of people over extremely long time periods. Some regulators
believe this is important because it means they can estimate the worldwide
cancer risk from releasing radioactive isotopes into the environment with
half-lives of thousands of years
(91av, 24 March, p 17).

But the ICRP says that the notion of collective dose has proved “unsuitable”.
Often it covers the threat posed by radiation to the entire world population for
the rest of time. Instead, the 17-member commission is thinking of introducing a
“group” or “workforce” dose limited to measuring the exposure of smaller numbers
of people over shorter timescales, though it hasn’t yet specified how many or
how long.

This amounts to “a green light to continuing pollution”, according to Ian
Fairlie, a consultant in environmental radioactivity who has worked for
regulatory agencies and anti-nuclear groups. Under the new system, it may be
possible to quantify the risk to a few specific individuals from radioactive
waste pumped into the sea, for example. But it doesn’t take into account the
risk of more cancers in the population sometime in the future. “This sits
uneasily with growing awareness about the effects of radiation on the
environment,” Fairlie says.

Britain’s advisory Committee on the Medical Aspects of Radiation in the
Environment (COMARE) has also told ICRP that it would be “very reluctant” to
abandon collective dose. COMARE chairman Bryn Bridges says the concept gives
governments and the public an estimate of how future health will be affected by
radioactivity—but he thinks the collective dose should cover just 500
years.

ICRP points out that the current system is founded on the risk that ionising
radiation poses to society as a whole. It wants to shift this to a regime that
concentrates on an individual’s risk. But for the moment it is not planning to
abandon the underlying assumption that any level of exposure to radiation,
however small, carries a potential risk.

ICRP chairman, Roger Clarke, denies the new system would be a licence to
pollute because it would reduce the radiation doses of the most exposed groups
of individuals. It will also make it simpler to enforce safety limits—10
different limits, as well as collective doses, are in operation at the moment,
he says. “The proposal is to try and rationalise this complex and widely
misunderstood system.”

But radiation scientists defend the existing system. “If it ain’t broke,
don’t fix it,” says Geoffrey Webb, president of the International Radiation
Protection Association.