Governmental Risk Assessments and Standards
Because exposure to high-level ionizing
radiation is known to cause cancer and
other health problems, public health regulators
have taken a cautious approach. They
assume that any exposure could cause similar
effects. They have established protective
standards by directly extrapolating the risks
from high doses of radiation to minimize
the risks of exposure to low doses. Much of
the current controversy surrounding radiation
is based on whether we should assume
low doses also cause health affects.
Since most scientists assume that any radiation
exposure entails some risk, how do we
decide what level of risk is justified by the
benefits of its use? In life, there is always a
statistical chance that some people will
contract certain diseases. Scientists and
public health professionals perform risk
assessments to determine the additional
likelihood of being harmed from exposure
or from certain behaviors. For a carcinogen
such as radiation, risk is the additional likelihood
of contracting cancer from exposure.
Over the years since radiation was first discovered
and used, the government has constantly
tightened the standards that limit
the amount of radiation to which workers
and the public can be exposed. The national
and international regulatory standards for
radiation exposure are based on more
research and more direct evidence of health
effects than for almost any other hazardous
substance. By setting and enforcing strict
exposure standards, governments have tried
to balance the benefits of using radiation
with the risks.
Individual Judgments
Making judgments on safety for society as a
whole is primarily the government's responsibility. But each of us as
individuals can also avoid unnecessary
exposure to radiation, so that we derive the
benefits from radiation and do not undergo
more risk than necessary.
It is always prudent to avoid unnecessary
exposure. However, refusing xrays or radiation
therapy may cost more money, time,
convenience, or health problems, than taking
advantage of radiation's unique diagnostic
and healing properties. Each of us must
make such decisions based on our tolerance
for risk, and our confidence in doctors and
their medical advice.
Society's Judgments, Pro and Con
Society as a whole must balance the risks
and benefits associated with nuclear energy,
including the use of radiation. Nuclear
advocates argue that nuclear power is a
proven, secure, and inexhaustible long-term
source of energy. They argue that nuclear
energy creates little air pollution, and contributes
almost nothing to global warming.
Nuclear energy could become increasingly
important in the twenty-first century as
global energy demands continue to rise, and
nonrenewable energy sources, such as fossil
fuels and natural gas, are slowly depleted.
Proponents say that nuclear power, if properly
managed, can benefit humanity and the
environment with a level of risk no greater
than that we routinely accept as part of our
normal lives.
Critics of nuclear power, however, ranging
from environmentalists to antiwar activists,
point to a variety of problems with nuclear
energy, including:
- The dangers inherent in transporting and disposing of the thousands of tons of high-level radioactive waste, now in temporary
storage at nuclear power plants across the nation.
- The possibility that radioactive material used by and generated in nuclear reactors could be diverted by rogue nations (or terrorists) to produce nuclear weapons.
- The risk of a dangerous accident, particularly in aging reactors whose protective systems may have been weakened or whose containment structures may be inadequate to prevent the release of
radioactivity into the environment.
- The siting of nuclear plants in densely populated areas, which increases the danger that an accident or terrorist attack could expose large numbers of people to dangerous levels of radiation.
- The unique problems associated with dismantling and decommissioning nuclear facilities, and cleaning up sites after they
are closed down.
Some opponents of nuclear energy argue
that the problems are so serious that we
should shut down the nuclear power industry.
A better alternative, nuclear critics
claim, would be to focus attention and
resources on developing safe, nonpolluting,
renewable energy sources such as solar,
wind, and geothermal power.
Future Prospects for Nuclear Power
Partly because of these disagreements, the
future of nuclear power is mixed. Even
advocates acknowledge that few if any new
nuclear power plants are likely to be built in
the United States in the next decade. In
part, this is due to the lack of public support.
A March 1999 Associated Press poll,
taken 20 years after Three Mile Island,
showed that only 45 percent of Americans
support the use of nuclear energy, 10 percent
fewer than in 1989.
Recent energy supply problems in
California, however, have sparked some
renewed interest in nuclear power. Another
limiting factor is the high cost of building
new nuclear plants. In addition, many of
the existing plants now nearing the end of
their useful lives are unlikely to be replaced,
at least right away. Many will seek licenses
to operate for a longer time period.
Government and industry experts continue
to design safer reactors, work to improve
techniques for decontaminating older reactors,
and find safer, more secure ways to
handle and dispose of radioactive wastes.
Some proponents expect nuclear energy to
contribute to a growing share of the world's
increasing energy needs in spite of continued
protests and controversy. (For more information, see Nuclear Energy Institute.)
December 11, 2002
