Letter from Dr G A Jamal, MB ChB MD PhD
FRCP
CABIN AIR
SAFETY
I am submitting this on a personal basis. My
qualifications are MB ChB MD PhD FRCP. I am a consultant physician
with specialisation in the field of clinical neurophysiology and
I have a special interest in the neurological and neurophysiological
assessment of the effects of neurotoxic factors on the peripheral
and central nervous system. I have published extensively on the
effect of organophosphate compounds on human health.
Within the last few years I have seen many pilots,
co-pilots and cabin crew members as well as passengers who have
had episodes of exposure to fume incidents. I have run extensive
neurological and clinical neurophysiological assessment on them.
Aircrews have presented for testing some time
after advising of exposures to aircraft contaminated air, specifically
oil lubricant exposure containing organophosphates and a mixture
of hydrocarbons. Given that the toxic substances involved in air
fume contamination events have high affinity to lipid material
and given that the bulk of the nervous system both peripheral
and central is phospholipids, the nervous system is one of the
prime toxic targets and is one of the most seriously affected
systems in the body both in the short term and in the longer term.
I found that the most commonly encountered manifestations
include confusion, drowsiness, fogginess in the head, excessive
tiredness, loss of balance and co-ordination, dizziness, clumsiness,
headaches, pins and needles and numbness sensation in the extremities,
generalised pain and aches. Other common manifestations include
difficulty with concentration and short term memory, mood changes,
disturbances of sleep and difficulty in finding words. There may
be development of intolerance to alcohol and increased sensitivity
to a number of chemicals. Other common manifestations include
visual blurring, tinnitus, sweating disturbances, bloating, nausea,
loss of sexual drive and frequency of micturition.
We have investigated these cases systematically
and thoroughly with tests looking at the function of the peripheral
and central nervous system and the autonomic nervous system. The
tests undertaken include EMG and Nerve Conduction Studies, Quantitative
Sensory Tests (large fibre VPT and small fibre TTT), Single Fibre
Jitter measurement, Multimodality Evoked Potentials (VEP, BAEP
& SEP), Cognitive Evoked Potential (CEP & P300) and EEG.
Other useful investigations include Neuropsychometric Tests and
Autonomic Nervous System Tests. We have aspired to do Brain Functional
Imaging (PET & SPECT Scan) but have not done so purely because
of cost issues. We have found evidence of abnormalities in this
group of patients to variable degrees including peripheral neuropathy
particularly small fibre neuropathy and other central abnormalities
as well as evidence of dysautonomia with a particular pattern.
The findings seen are similar to those found in cases of exposure
to organophosphate esters and solvents. Accurate diagnosis is
essential not only to characterise the ailment but also to instigate
effective management.
18 June 2007
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