Risk Double Earlier Estimates
Passive smoking may be much more dangerous
than scientists had thought, researchers said on Wednesday in
new study that is likely to boost demand for a ban on smoking
in public places.
Earlier research into the effects
of second-hand smoke had focused on non-smokers living with smokers.
Scientists in Britain studied exposure to passive smoke by measuring
a breakdown product of tobacco smoke called cotinine in the blood
They found high concentrations
of blood cotinine levels were associated with a 50-60 percent
higher risk of coronary heart disease (CHD).
Previous studies had estimated
the raised risk of heart disease from passive smoking in non-smokers
at 25 to 30 percent.
"We've studied only people who
are non-smokers and seen how their levels of cotinine, which reflect
the amount of passive smoking they have been exposed to, and then
related it to their subsequent heart disease risk," Professor
Peter Whincup, of St George's Hospital Medical School in London,
said in an interview.
"People who were non-smokers but
had relatively high levels of cotinine had a heart disease risk
of about 50 percent higher than those people who were exposed
to low levels," he added in an interview.
Whincup, who reported the findings
on BMJ Online First, said the research provides further evidence
that passive smoking has adverse effects which may have been underestimated
in the past.
Supporters of a ban on smoking
in the workplace, bars and restaurants described the findings
are further evidence for new smoking legislation.
"The need for a ban on smoking
in public places in the UK has never been better illustrated than
by this potentially pivotal study. We have known for some time
that passive smoking was strongly associated with increased risk
of coronary heart disease (CHD), but this study strengthens the
evidence considerably," Dr Tim Bowker, of the British Heart Foundation
which partly funded the research, said in a statement.
"The evidence is now compelling.
The government should not delay any further in introducing legislation
to protect non-smokers from this unnecessary risk," he added.
Ireland recently became the first
country to introduce a national ban on smoking in public places.
New York and parts of Australia have taken similar measures.
Reference Source 89