Radiation Facts
Different types of Radiation
All parts of the electromagnetic
spectrum are described as ‘radiation’,
but not all radiation is the same.
At the top of the scale, ionising radiation (as in
radioactive decay or x-rays) has the ability to alter
matter, including human cells. It has very high energy
which can change a molecule’s structure. This
can have serious consequences – ionising radiation
can cause changes in the structure of DNA, leading
to mutations and in some cases cancer.
By contrast radio waves, such
as in mobile phones are at the
other end of the spectrum. They
have very low energies and do not
have the ability to alter matter,
so they are classed as non-ionising
radiation.
Non-ionising radiation does not break
molecular bonds. It arises from the
lower end of the electromagnetic
spectrum, from the electromagnetic
fields created by radio and television
transmissions, domestic microwave
ovens, and mobile telephones.
Effects
on health
Heating is the main biological
effect of the electromagnetic fields
created by radio waves. In microwave
ovens this fact is employed to
warm up food. The levels of such
fields to which people are normally
exposed are very much lower than
those needed to produce significant
heating. The heating effect of
radio waves forms the underlying
basis for current guidelines. Scientists
are also investigating the possibility
that effects below the threshold
level for body heating occur as
a result of long-term exposure.
To date, no adverse health effects
from low level, long-term exposure
to radio waves or power frequency
fields have been confirmed.1
It is noted that electromagnetic fields above certain
levels can trigger biological effects. Experiments
with healthy volunteers indicate that short-term exposure
at the levels present in the environment or in the
home do not cause any apparent detrimental effects.
Exposure to higher levels that might be harmful is
restricted by national and international guidelines.
According to the World Health Organisation (WHO), over
25,000 articles have been published on the effects
of non-ionising radiation over the past thirty years. “Based
on a recent in-depth review of the scientific literature,
the WHO concluded that current evidence does not confirm
the existence of any health consequences from exposure
to low level electromagnetic fields”
Electromagnetic Fields
The guidelines on exposure to
electromagnetic fields are set
by the International Commission
on Non-Ionising Radiation Protection
(ICNIRP). This body, which is recognised
by the WHO, reviews scientific
literature from around the world
and produces guidelines from this
work. RTÉNL strictly adheres
to these guidelines at all of our
sites.
Everyone is subjected to magnetic fields even within
the home. Microwave ovens, TV sets, radios, and even
the vacuum cleaner, all create electromagnetic fields
which emit small amounts of non-ionising radiation.
The amounts emitted are very small and well below the
accepted international threshold level (100_T).2 Outside
the home, security tag systems in shops, metal detectors
in airports etc. Also create electromagnetic fields
which are well below the threshold.
An important point to bear in mind is that electromagnetic
fields diminish the further one is from the source.
Mobile telephone base stations create electromagnetic
fields. These fields are created by the antennas, which
are normally at least 15m from the ground, as they
transmit signals parallel to the ground to mobile phones.
At ground level, the electromagnetic radiation level
is very small and well within guidelines. In fact,
the exposure level is 1/5 that of a domestic microwave
oven.
The role
of Comreg
The Irish Commission for Telecommunications
Regulation (Comreg), takes compliance
with international guidelines on
exposure to non-ionising radiation
very seriously.3 To date,
several audits of sites have been
undertaken by Enterprise Ireland,
as a standards body on behalf of
Comreg, to evaluate the measures
that site operators have in place
and the actual levels of non-ionising
radiation produced. These audits
have been based on large samples
of sites around the country. All
operators have appropriate procedures
in place and the levels of non-ionising
radiation are well within guidelines.
References
- World Health Organisation – What
are Electromagnetic Fields? (fact
sheet)
- ICNIRP
- Comreg – Compliance with
emission limits for non-ionising
radiation – third party
report (Doc No. 01/85)
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