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Smokers
Risk Their Partners' Lungs
(HealthScout)
-- Women living with people who smoke take in five to six times
more cancer-causing chemicals than do women who live in homes
where no one smokes, a new study shows. The study is the first
time science has shown how people may get lung cancer from secondhand
smoke, say the researchers.
Secondhand
smoke puts women at a higher risk for lung cancer, says lead author
Kristin Anderson, an assistant professor at the University of
Minnesota's Cancer Center in Minneapolis. "That's been observed
in many studies over time. We were interested in trying to find
biochemical explanations for that higher risk. What we were looking
for was tobacco-specific lung carcinogens, which can only be found
in tobacco products."
Secondhand
smoke causes about 3,000 lung cancer deaths each year among nonsmokers,
according to the U.S. Environmental Protection Agency. The EPA
says your risk of getting lung cancer goes up by 20 percent if
you're exposed long term to secondhand smoke.
"We advertised
for volunteers and found 23 women who had a male partner who smoked
in the home as well as 22 couples with a male partner who did
not smoke," Anderson says. "The couples had to be together for
a least six months." None of the women smoked.
Anderson and
her colleagues analyzed the women's urine and found that the women
who lived with smokers had five to six times higher levels of
the carcinogens NNAL and NNAL-Gluc than women who lived with nonsmokers.
Both of these substances are tobacco-specific carcinogens and
are byproducts in the body of the tobacco-specific lung carcinogen,
NNK.
"That means
they had higher levels of NNK in their bodies, a chemical we know
in animal models is a potent lung carcinogen. It is also highly
suspected for causing cancer in humans," Anderson says. NNK is
broken down in the body into NNAL and NNAL-Gluc and is then excreted,
she explains.
The women
also had five to six times the amount of nicotine and cotinine
(a metabolic byproduct of nicotine) than those who lived with
nonsmokers, Anderson says.
"It's one
more piece of evidence linking passive smoking with lung cancer
in women," Anderson says. "The evidence probably applies to men,
but we don't know that yet. That needs further research."
The findings
are in today's issue of theJournal of the National Cancer Institute.
Anderson's
study is important because it shows that the path of secondhand
smoke to lung cancer is "biologically plausible," says Anthony
Alberg, an assistant professor of epidemiology and oncology at
Johns Hopkins School of Hygiene and Public Health in Baltimore.
"There has been a lot of criticism of earlier studies that showed
a link between secondhand smoke and lung cancer, saying that the
lung cancer could be explained by things that differed in the
households of smokers versus nonsmokers."
"This study
is an important study because it provides a direct link between
exposure to secondhand smoke and the metabolites of tobacco,"
says Alberg. This is the first time that researchers have seen
tobacco-specific elements in urine, he adds.
People are
not only at risk for lung cancer from secondhand smoke, adds Dr.
Michael Thun, the director of epidemiological research for the
American Cancer Society in Atlanta. "The take-home message from
this study is that in public spaces regulations that restrict
smoking are extremely important in reducing exposure of nonsmokers.
"But clearly,
it's a more difficult issue in the home," Thun continues.
"People have
to realize that nonsmokers who live with smokers are exposed to
increased risk from a broad spectrum of risks," Thun says. "It's
not only lung cancer, it's heart disease, respiratory difficulties
in children, even middle-ear infections."
Stop smoking.
Now. If you can't, talk to your doctor about various programs
and treatments that may help you quit.
For
more information on the effect of secondhand smoke on women and
children, see the
American Lung Association or the
Centers for Disease Control and Prevention.
For
help in quitting, try the
QuitNet Quit Smoking Guide.
Reference
Source 101
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
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