By
Lyndsay Moss, Sydney Morning Herald, August 23, 2004
Smokers
pump out clouds of poison which can seriously affect the breathing of those
around them, new research has found.
For
the first time scientists have shown that endotoxins, which are made by bacteria
and occur naturally in the air, are produced by tobacco smoke in high
concentrations.
The
findings will add to growing calls for a ban on smoking in enclosed public areas
such as pubs, restaurants and other workplaces.
The
researchers, from Lund University in Sweden, used a unique method of chemical
analysis, developed over many years, to measure levels of endotoxins caused by
tobacco smoke.
Tobacco
is known to contain more than 4,000 chemicals, including 50 substances known to
cause cancer.
Endotoxins
are a group of poisonous substances produced by bacteria and naturally occur in
the air and elsewhere.
In
normal, low concentrations they are not dangerous and may even play a role in
protecting people against allergies.
But
in high concentrations endotoxins can cause serious inflammatory reactions in
the respiratory tract, leading to bronchitis and asthma.
The
substances are known to pose a health risk in many workplaces, coming from
construction materials, dust and plants.
They
can also contribute to asthma in the home environment.
But
it has not been clearly shown before that cigarette smoke contains true
endotoxins - bacterial lipopolysaccharides.
The
Swedish team, led by Associate Professor Lennart Larsson, tried to simulate both
passive and active smoking.
They
set up equipment that "smoked" a cigarette for around 10 minutes,
capturing the contents of the smoke in a filter.
To
simulate passive smoking, they "smoked" one cigarette every half an
hour in an unventilated room for seven hours, comparing it with a similar room
without smoke.
They
found that the level of the toxic substances in the air of the smoky room was
120 times higher than in the smoke-free room.
The
team, writing in the journal Indoor Air, also concluded that the tobacco
endotoxin appeared to be the most aggressive type among the various forms that
exist.
They
said they had been able to verify research by US scientist Jeffrey Hasday which
showed there may be endotoxins in cigarette smoke.
"This
can be one reason why smokers so often suffer from respiratory ailments,"
Prof Larsson said.
"The
fact that passive smoking entails exposure to extremely high concentrations of
endotoxins is an entirely new breakthrough."
Amanda
Sandford, from campaign group Action on Smoking and Health (ASH) [UK], said the
findings were "very interesting".
"This
research may lead to a greater understanding of how tobacco smoke can trigger
respiratory diseases such as asthma," she said.
"There
are lots of sources of pollution we don't have much control over, but we can
control tobacco smoke in enclosed areas."
Sandford
said the study underlined the need for a ban on smoking in indoor environments
to protect the people who work and go there.
"We
already know that smoking is the trigger for asthma.
"It
is not a case of having to wait for more evidence. We have enough evidence, now
it's time for action," she added.
The
UK government is currently considering whether to follow countries like Ireland
and ban smoking in enclosed public places.
A
public health White Paper due to be published later this year is expected to
address the issue.
Larsson
said he hoped their findings could be used in future anti-smoking campaigns.
The
team now wants to study whether endotoxins from tobacco smoke can fasten on to
dust particles, meaning they linger in the environment where someone has smoked.
They
also want to see how ventilation influences levels of endotoxins from cigarette
smoke in indoor air.
From
Innovations
Report :
Endotoxins
in cigarette smoke
Lund University, Sweden 19/8/04
A room where people smoke contains dozens or
hundreds of times higher air concentrations of endotoxins than smoke-free indoor
air. This has been shown by a research team from Lund University. Endotoxin is
the name of a group of poisonous substances produced by bacteria and naturally
occurring in the air and elsewhere. In normal low concentrations, endotoxins are
not dangerous; indeed, they might play a role in protecting us against
allergies. But at higher levels of concentration they induce serious
inflammatory reactions in the respiratory tract.
Endotoxins have long been known for their powerful capacity to cause
inflammations. Dust rich in endotoxins constitutes a health risk in many
workplaces and is seen as a key explanation for the high incidence of chronic
bronchitis among farmers. Endotoxins from construction materials, dust, plants,
etc. in the home can also contribute to asthma. On the other hand, it had not
been clearly shown previously that cigarette smoke contains true endotoxins,
i.e. bacterial lipopolysaccharides.
In its experiments, the Lund team, headed by Associate Professor Lennart
Larsson, has tried to simulate both passive and active smoking. For the latter,
they set up equipment that “smoked” a cigarette in 8-10 minutes and captured
the contents of the smoke in a filter. For passive smoking, they “smoked”
one cigarette every half hour in an unventilated room for seven hours and
compared it with a similar room without smoke. The results, presented in the
international journal Indoor Air, show that the level of the toxic substances in
the air of the smoky room was a full 120 times higher than in a smoke-free room.
Moreover, the tobacco endotoxin seemed to be the most aggressive sort among the
various forms that exist.
The key to the finding is a unique method of chemical analysis that the Lund
scientists have developed over many years to identify endotoxins in clinical
trials and environmental tests. Using this method, they have verified the
results presented a few years ago by the American scientist Jeffrey Hasday
indicating that there may be endotoxins in cigarette smoke.
“This can be one reason why smokers so often suffer from respiratory ailments.
The fact that passive smoking entails exposure to extremely high concentrations
of endotoxins is an entirely new breakthrough” says Lennart Larsson, who hopes
the new knowledge will be of use in anti-smoking campaigns.
The Lund team now wants to move on to see whether endotoxins from tobacco smoke
can fasten onto particles of dust, thereby lingering in an environment where
someone once smoked. They also aim to study how ventilation influences the
levels of endotoxins from cigarette smoke in indoor air.