| What causes ES?
The exact causes of
environmental sensitivities are unknown. Several causal theories
(or theory of what causes the condition) for ES/MCS have been
proposed since the 1950’s,
but attempts to test them have been slowed by varying case definitions,
and the high cost and highly challenging nature of the required
research.
One theory is that humans’ capacities to adapt to a multitude
of new chemical exposures are being strained. The production of
new man-made chemicals has sky-rocketed since the second world
war, with approximately 75,000 – 85,000 chemicals in circulation
in North America in the late 1990’s and an increase of approximately
2.000 – 3,000 more each year.
Although it cannot be
stated that this increased exposure to synthetic chemicals in
products, and to other pollutants released by industrial
processes, has “caused” environmental sensitivities/MCS,
it has been suggested that those who report sensitivities to multiple
chemicals may be more susceptible, like the canaries that signalled
the presence of poison gasses in coal mines, enabling miners to
escape before they, too, were poisoned. Certainly the evidence
linking other illnesses with low-level environmental exposures
is increasing (see Environmentally-linked
illnesses).
A recent causal hypothesis
by a researcher named Martin Pall, suggests that stressors (whether
physical, chemical, biological or psychological) increase the levels
of a chemical called nitric oxide in the body, which in turn reacts
with something called superoxide to form the strong oxidant known
as peroxynitrite. Once this happens, a vicious cycle of wide-ranging “oxidative
stress” is started and maintained, which is consistent with
the chronic and multi-system nature of ES/MCS, as well as the overlapping
illnesses, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS
and Fibromyalgia (FM).
Other recent research
suggests that, because of genetic differences, some individuals
reporting ES may be more susceptible than others
to developing particular symptoms and/or have more difficulty
breaking down and eliminating certain environmental contaminants.
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