STF NA MÍDIA

JUSTIÇA NO EXTERIOR •
THE GUARDIAN (LO) • ENVIRONMENT • 20/9/2011
Traffic fumes can trigger heart attacks, say researchers
Study published in the British Medical Journal identifies pollutant particles and nitrogen
dioxide as main culprits
Denis Campbell
Breathing in large amounts
of traffic fumes can trigger a
heart attack up to six hours
after exposure, according to
research which reaffirms the
health risks associated with
pollution.
The study, in the British Medical
Journal, found that high
levels of pollution can increase
the risk of suffering a
heart attack. It identifies exposure
to pollutant particles
and nitrogen dioxide expelled
by cars, which are both
markers of contaminated
urban atmospheres, as the
main culprits.
The authors quantify the risk
as small – up to 1.3% higher
risk of a heart attack up to six
hours after exposure to those
substances. But they say that
getting enough of those two
substances into the lungs can
bring forward by a few hours
a heart attack that would have
happened anyway. This is
called short-term displacement
or the "harvesting" effect
of pollution.
Krishnan Bhaskaran and six
colleagues at the London
School of Hygiene and Tropical
Medicine examined
79,288 heart attacks that occurred
in 15 urban areas of
England and Wales in 2003-
06, from the Myocardial Ischaemia
National Audit Project.
They then examined
how much pollution occurred
in those areas at the time
those patients suffered their
heart attack, using data from
UK National Air Quality
Archive.
They studied levels of carbon
monoxide, sulphur dioxide
and ozone as well as pollutant
particles, known as
PM10, and nitrogen dioxide
or NO2.
"We estimated that higher
ambient levels of the trafficassociated
pollutants, PM10
and NO2, were followed by a
transiently increased risk of
myocardial infarction up to
six hours later," the authors
write.
The study emerges as the
government is facing legal
action from the environmental
group Client Earth for not
protecting the health of people
in towns and cities from
pollution s damaging effects.
Chris Huhne, the energy and
climate change secretary, is
likely to face a judicial review
before Christmas.
Pollution is estimated to cause
29,000 premature deaths a
year in the UK, including
4,200 in London alone, said
Jenny Bates, an air pollution
campaigner at Friends of the
Earth.
"This study adds to the urgent
need for bold action to
cut air pollution in order to
comply with EU limits " she
said.
"It s outrageous that we re
continuing to breathe this
dirty air and that ministers
haven t done enough to clean
up our air."
Professor Jeremy Pearson,
associate medical director of
the British Heart Foundation,
which co-funded the study,
said: "This large-scale study
shows conclusively that your
risk of having a heart attack
goes up temporarily, for a-
round six hours, after breathing
in higher levels of vehicle
exhaust.
"We know that pollution can
have a major effect on your
heart health, possibly because
it can thicken the blood to
make it more likely to clot,
putting you at higher risk of a
heart attack.
"Our advice to patients remains
the same – if you ve been
diagnosed with heart disease,
try to avoid spending long
periods outside in areas where
there are likely to be high
traffic pollution levels, such
as on or near busy roads."
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