Radiation Hazard
Radiological energy is
one of the methods of treating some diseases requiring radiotherapy, but
besides treatment, the method can cause other complications in the body, writes
Steve Dada
The
World Health Organisation (WHO) recently revealed that exhaust fumes from
diesel engine could cause cancer. In a report by a WHO expert group, fumes from
the exhaust were categorised as cancer causing agent, especially lung cancer
and may also cause tumours in the bladder. It based the findings on research in
high-risk workers such as miners, railway workers and truck drivers.
However,
the panel said everyone should try to reduce their exposure to diesel exhaust
fumes. The International Agency for Research on Cancer (IARC), an affiliate of the
WHO, had previously labelled diesel exhaust as probably carcinogenic to humans.
IARC has now labelled exhaust as a definite cause
of cancer, although it does not compare its risk levels.
Diesel
exhaust is now in the same group as carcinogens ranging from wood chipping to
plutonium and sunlight to alcohol. It is thought that people working in
cancer-risk industries have about 40 per cent increased risk of developing lung
cancer.
Dr.
Christopher Portier, who led the assessment, said: ‘’The scientific evidence
was compelling and the working group’s conclusion was unanimous, diesel engine
exhaust causes lung cancer in humans. There are other human made items that are
capable of causing other diseases, but not known to man. The only thing that is
incontrovertible is the fact that some diseases that were alien to man in the
past are becoming increasingly feasible, as major cause of deaths, yet no
solution. It might even have to do with what man consumes.
The
industrial revolution has come with attendant hazards causing some toxicity to
human health and thereby endangering the health. What with industrial pollution
believed to have caused so much damage to human health through inhaling of
carbon monoxide believed to be most unfriendly to health. Fumes from common
generator used as back up for electricity when Power Holding Company of Nigeria
(PHCN) becomes fails to supply light, has killed many families who put the
generator within the apartment where they sleep.
Even
then, some medical equipment used to save life such as radio-active machines
have been found capable of causing some complications other than what they are
meant to cure. For example, some radiotherapy machines used to kill cancer
cells in cancer patients can cause cancer to a person who does not have the
disease but is unduly exposed to the radiation from the machine.
The
Nigerian Nuclear Regulatory Authority (NNRA) is a Federal Government
establishment charged with the responsibility for nuclear safety and
radiological protection regulation in Nigeria. It also has power to
provide training, information and guidance on nuclear safety and radiation
protection. The regulatory authority’s task is to provide information about
safety and regulatory measures without being promotional with respect to
regulatory activities.
In
her lecture at the Third NNRA Workshop on Nuclear Safety and Radiological
Protection in Abuja recently, Dr. Ekaette Bassey of the institution defined
radiation as a process in which particles with some energy travel through air
or material (skin and glass water, among other), which has impact on the
material through which it travels depending on its energy. Radiation is
produced by matter which is generally called a source and this can be natural
or artificial.
According
to her, there are both natural and artificial radiation sources. Natural
radiation sources include: environmental, air, food and drink, while artificial
radiation include: medical treatment, consumer products and occupational
exposure. Medical exposures from diagnosis and in treatment she noted account
for the largest dose from artificial sources.
Talking
about types of radiation, Bassey mentioned Alpha radiation, which she said has
a short range in air and can be stopped by paper or skin. This type of radiation
can also be hazardous and can enter the body by inhalation or ingestion, as
large exposures can result in damage to tissues, but alpha particles can be
stopped by sheet of paper or the outer skin.
She
also mentioned Gamma radiation, which is highly penetrating for which only
dense materials such as steel or lead can provide an effective shield. It can
deliver significant doses to internal organs without needing to be taken into
the body, but can pass through the body and even in some cases thick layers of
the lead or concrete.
There
is also Beta radiation that can penetrate further into materials or tissue, but
can be stopped by plastic, glass or matal and does not normally penetrate
beyond the top layer of skin but large exposures can cause skin burns and is
also hazardous if it enters the body.
According
to her, there are deterministic (short term) and stochastic (long term) effects
of radiation. The health consequences of radiological accidents are death, loss
of limbs, burns, while increased risk of stochastic effects can result to
cancer. It also has environmental contamination and socioeconomic consequences.
Bassey
warns that the public should protect themselves from radioactive sources,
saying that to do so if one suspects an object as a radioactive source, such
person should not touch or pick it up and should keep away from it by about 30
meters. She also advices such source should be cordoned to prevent access to
it.
However,
if such source is mistakenly touched, she advises that the hand must be kept
away from the mouth and the hand must be washed before eating or drinking or
smoking and immediately the NNRA or the police or emergency services must be
notified.
For
protection against effects of radiation, Bassey said it requires time, distance
and shielding. According to her, time allows people to minimise or at least
limit the amount of radiation exposure they receive, stressing that the longer
the exposure time, the higher the radiation dose, as the relationship between
time and exposure is linear.
Talking
about distance and shielding, she said distance from a source is a very
effective way to lower the radiation dose received. For shielding, radiation
can penetrate further into materials or tissue, but can be stopped by some
materials. The appropriate shielding can be used to decrease or minimise the
radiation exposure, she noted.
She
talked about some infrastructure for radiation protection and safety which
include: International Basic Safety Standards (BSS) for protection against
Ionizing radiation and the safety of radiation sources which defines the
requirements that need to be met within a national infrastructure for radiation
protection and safety.
One
such requirement is to set up appropriate means of informing the public, its
representatives and the information media about health and safety aspects of
the activities involving exposures to radiation and regulatory processes.
The
reasons for nuclear communication of the NNRA, Bassey noted, is to maintain
trust and confidence that nuclear technology is being operated at appropriate
safety standards, to facilitate the decision making process on nuclear matters
by presenting factual and balanced information and to learn from society about
their concerns and to address their concern (feedback).
The
greatest challenges of NNRA are funding to provide the necessary infrastructure
of operation to protect the public from dangers of radiological structures
through necessary information, greater government’s attention and greater
awareness on the part of the public about the activities and responsibilities
of NNRA to the people.
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