Rebuttal of FSID statement regarding the
Toxic Gas Hypothesis of Cot Death
FSID says:
In 1989 Mr Barry Richardson, a materials consultant, said that
his research showed antimony added to mattress PVC released a
toxic gas which, he said, caused cot death. In 1990 the
Department of Health and FSID commissioned studies to
investigate the claim but neither found any evidence to support
it.
WRONG. The 1990 UK
Department of Health investigation (1991 Turner Report) did find
evidence to support the toxic gas theory: the Turner Committee
achieved biogeneration of a form of stibine gas from cot
mattress material. Furthermore, the Committee recommended that
if antimony fire retardant was used in cot mattresses, the
levels of arsenic in the antimony should be as low as possible –
a tacit admission that mattresses could generate arsine gas.
FSID then refers
to the 1998 UK Limerick Report:
In 1994 The Cook Report broadcast
unpublished findings that cot death babies had higher antimony
levels in their blood and liver than babies who died of other
causes and asserted that the antimony came from cot mattresses.
Further extensive research was commissioned and reported in 1998
in the final report of Chief Medical Officer's Expert Group to
Investigate Cot Death Theories: Toxic Gas Hypothesis. Here are
some of the facts this and other scientific research has
established:
FSID says:
1. There is no difference in antimony concentrations in cot
death babies and other babies.
WRONG. Research
carried out in Britain in 1994 showed that post mortem
body tissue of cot death babies contained many times more
antimony than tissue of babies who had died of other causes. (FSID’s
claim came about because they used average figures, whereas for
such purposes individual figures must be used.)
FSID says:
2. Antimony is found in most babies and was reported in
scientific literature before the chemicals were present in
mattress PVC. Antimony is found in babies even before birth –
i.e. before they could have had any exposure to mattresses. It
could come from maternal diet, but antimony is everywhere in the
environment, including common household dust.
WRONG.
Antimony is a very rare element. It comprises about one
part per million (0.0001%) of the earth’s crust. In the
household environment antimony is present in significant
quantity only in polyvinyl chloride (PVC) sheeting and certain
upholstery and bedding. Also, detailed chemical analyses
of a range of food and other materials was carried out in
Britain in 1994, and antimony was found to be virtually absent.
FSID
says:
3. Antimony was not added to mattresses in the UK before
1988 and yet cot deaths were occurring at the rate of about
2,000 per year well before then. There are currently just under
350 cot deaths per year. The year after antimony was first added
to mattresses, 1989, was the year that cot deaths began to
decrease.
FIRST PART WRONG; SECOND
PART MISLEADING. The facts are as
follows: Antimony was first introduced into cot mattresses
in Britain in the early 1950s, and the British cot death rate
increased steadily from that time onwards. The highest cot
death rates in Britain (1986-1988) coincided with the highest
concentration of antimony in cot mattresses. The British
Government had required fire retardant to be incorporated in cot
mattresses by 1988. Manufacturers were given four years’
warning, and during this period moved towards compliance with
the new standard.
Certainly the British
cot death rate fell while the amount of antimony in mattresses
was high; but that was because from mid-1989 onwards British
parents took preventive measures against toxic gas generated in
their babies’ mattresses. Furthermore, manufacturers began to
remove antimony from cot mattresses.
In June 1989 the
toxic gas theory for cot death was publicised nationwide in
Britain, and advice given either to use a new mattress for every
baby, or to wrap mattresses in polythene. The cot death rate
immediately began to fall (the first reduction in cot death in
Britain) and it had fallen 38% by the time the “Back to Sleep”
(face-up sleeping) campaign was introduced in December 1991 (2½
years later).
FSID
says:
4.
The claim that the decrease was due to publicising the
advice to wrap mattresses is unfounded. In the CESDI study
(Confidential Enquiry into Stillbirths and Deaths in Infancy),
the UK's largest study into cot death, only 2% of mattresses in
the UK were found to be wrapped, and the study found that
babies had actually died on wrapped mattresses. The claim
by Cot Life 2000 that this is because the mattresses were
wrapped incorrectly is unsubstantiated. As CESDI is a
confidential enquiry with the data being completely anonymous,
it is not possible for anyone to know whether the wrapping was
"incorrect".
FIRST PART IRRELEVANT;
SECOND PART WRONG.
As stated above, the advice publicised
nationwide in Britain in June 1989 was that parents should use a
new mattress for each new baby OR they should wrap their
existing mattress in polythene sheeting. And it is quite clear
that many parents took the first option: sales of new cot
mattresses jumped by around 15%. So FSID’s statement that only
2% of mattresses were wrapped is irrelevant – many parents took
the option of buying a new mattress instead.
FSID
also repeats the
claim that babies in the CESDI Study had actually died on
mattresses wrapped for cot death prevention. The claim is
unsubstantiated. In February 2000 Professor Peter Fleming
(an author of the CESDI Study) publicly conceded publicly on
Radio New Zealand that he could not demonstrate that the
mattresses in question had been wrapped to the Cot Life 2000
specifications for cot death prevention.
FSID
says:
5.
Cot death occurs in countries where no antimony has ever
been added to mattresses.
IRRELEVANT.
Of course
cot death can occur in countries where no antimony has been
added to mattresses. That comes about because antimony can be
naturally present in materials used for infant bedding (e.g.
sheepskins). Also antimony is used as a catalyst in the
manufacture of PVC and several other fabrics. So antimony can
be present in infant bedding even if it has not been added
knowingly to manufactured items.
FSID says:
6.
When comparing babies who die with those who live,
proportionately more of the babies who lived slept on PVC
mattresses. This may be because it is easier to keep such
mattresses clean. A Scottish study found that previously-used
cloth or "ventilated" mattresses (which are more difficult to
keep clean) are associated with an increased risk of cot death.
However, the same study found that used mattresses with a full
integral PVC covering were not associated with an increased risk
of cot death.
MISLEADING.
Provided
PVC doesn’t contain any phosphorus, arsenic or antimony, it is
an excellent mattress covering. And following the nationwide
publicity about the toxic gas theory in Britain in June 1989,
mattress manufacturers began removing those chemicals from the
PVC which they used to cover cot mattresses. So of course the
cot death rate on PVC-covered mattresses in Britain went down.
FSID says:
7.
Several research groups have replicated Mr Richardson's
original experiment but their findings do not substantiate his
conclusions, even though Mr Richardson co-operated fully with
one of the attempts and agreed that the same methodology had
been followed. In other words, in normal cot-like conditions it
is not possible to generate toxic gas from antimony encapsulated
in mattress PVC.
WRONG. The UK Turner
Committee (which investigated the toxic gas theory in the early
1990s) proved the toxic gas generation concerned. And in the
case of the Limerick Committee’s investigation of the theory, a
technical critique issued by Barry Richardson after the release
of the Limerick Report demonstrates that the Limerick Committee
did not replicate his test methods. Furthermore the Limerick
Committee researchers refused to listen when Richardson tried to
point out their errors in technique. The former Chief Executive
of the New Zealand Cot Death Association, Mr Lee Schoushkoff,
conceded that the Limerick Committee did not replicate
Richardson’s test methods.
* * * * * *
With regard to their
cot death prevention advice, FSID says:
FSID continues to
encourage parents to follow the evidence-based advice to Reduce
the Risk of cot death:
FSID says:
·
Place your baby on the back to
sleep
This is deficient
advice. Face-up sleeping is only a partial preventive against
cot death. The reason why face-up sleeping reduces the cot
death risk is simple: the gases which cause cot death (phosphines
generated from phosphorus, arsines from arsenic, and stibines
from antimony) are all more dense than air, and therefore a baby
sleeping face-up is less likely to inhale them. However,
face-up sleeping is not a failsafe cot death prevention, for a
number of reasons:
a)
Babies placed to sleep face-up frequently roll onto their
stomachs.
b)
Face-up sleeping is not very effective in preventing cot
death in cots, prams and carrycots etc. which have enclosed
sides, as these can cause gas to be trapped around a baby.
c)
Face-up sleeping is not very effective against the danger
of phosphine, as this gas is only slightly more dense than air.
Any phosphine generated is likely to be present in the air which
a baby breathers, even if the baby is sleeping face up.
d)
Phosphines, arsines and stibines can be ingested by a
baby not only by inhalation – these gases can also be absorbed
through a baby’s skin. And sleeping position, of course,
provides no protection against ingestion of gas through the
skin.
FSID says:
·
Cut smoking in pregnancy -
fathers too!
·
Do not let anyone smoke in the
same room as your baby
In actual fact,
smoking does not cause cot death, as recent history shows:
Smoking was very
common in Britain in the 1930s and 1940s, yet cot death was
virtually non-existent. Smoking is prevalent in present day
Russia and the former Yugoslavia, yet cot death is rare in those
regions.
By contrast, smoking
is on the decline in the USA, but the cot death rate remains
fairly static.
Furthermore, no
cause-and-effect relationship between smoking and cot death has
ever been established. In fact, they are simply socio-economic
parallels. Put another way, smoking is more common among poorer
people – and so is cot death. But it does not follow that
smoking is therefore a cot death risk factor.
FSID says:
· Do not let your baby get too
hot
In actual fact,
overheating is a cot death risk only if a baby is sleeping on a
mattress which is not wrapped for cot death prevention. The
reason why overheating increases the risk of cot death on
UNWRAPPED mattresses is because a rise in temperature results in
increased gas generation (an increase in temperature of three
degrees C (5F) can cause gas generation to increase around
tenfold). However, if a baby is sleeping on a WRAPPED
mattress, overheating is irrelevant to cot death.
FSID says:
· Keep your baby's head uncovered
- place your baby with feet to the foot of the cot, to prevent
wriggling down under the covers
While it is certainly
correct that babies should sleep with their heads uncovered,
sleeping a baby with feet to the foot of the cot affords no
protection whatsoever against cot death. Any area on an
unwrapped mattress where a baby sleeps is a potential source of
toxic gas, since that is the area which becomes warm and moist
(promoting the fungal activity which can cause gas generation).
FSID says:
·
If your baby is unwell, seek
medical advice promptly
This is good general advice, but it has little to do with cot
death prevention. Cot death is not caused by a medical
condition (cot death babies are not ill in the medical sense) –
this mechanism of death results from environmental poisoning.
If the environmental conditions which can result in toxic gas
generation are present in a baby’s cot, cot death risk is also
present, regardless of whether the baby has recently seen a doctor.
FSID says:
· Avoid falling asleep with your
baby on a sofa
FSID’s advice is
correct, but they fail to state the reason why sleeping on a
sofa can result in cot death risk. The reason is that sofas
almost invariably contain compounds of phosphorus, arsenic
and/or antimony – and therefore these items of furniture are
capable of the toxic gas generation which causes cot death.
Most sofas are padded with polyester fill, and polyester
invariably contains antimony (used as a catalyst in the
polymerisation process).
FSID says:
·
Sleep your baby in a cot in
your room for the first six months
This is misleading advice. If a baby’s
cot mattress and/or bedding is capable of the toxic gas generation which causes cot death, cot death risk will be
present in the cot regardless of whether the cot is in the
parents’ bedroom. Sleeping the baby in the parents’ room will
reduce cot death risk only if the parents are awake (or wake up)
and monitor the baby.
FSID says:
·
Do not share a bed with your
baby if you or your partner are smokers, have been drinking
alcohol, take drugs or medication that makes you drowsy or are
excessively tired
This is misleading
advice. The cot death risk posed by bedsharing does not arise
from smoking – it arises from the mattress. Adults’ mattresses
frequently contain the same chemicals and household fungus as
babies’ mattresses and therefore can generate the toxic gases
which cause cot death. (For physiological reasons adults are
not put at risk by gas generated from mattresses.) Therefore
the correct advice on bedsharing is that bedsharing between
adults and babies should not occur under any
circumstances. FSID’s advice on bedsharing is deficient.
SUMMARY
FSID’s cot death
prevention advice is deficient and misleading.
Dr T J Sprott OBE
MSc PhD FNZIC
Consulting Chemist
Forensic Scientist
Auckland, New Zealand
Used with permission of Cot Life 2000, emphasis added
