Many Teens Exposed to Secondhand Smoke
Those Teens May Be More Likely to Take Up Smoking; Secondhand Smoke May Also Up Kids' Asthma
May 24, 2007 -- Secondhand smoke is part of daily life for many youths
worldwide, and it may make children more likely to get asthma and teens more
likely to smoke.
That's according to two separate studies -- one from the CDC and one from a
researcher at Columbia University's Mailman School of Public Health.
The CDC reports that nearly half of teens who took part in international
surveys reported exposure to secondhand smoke -- and those teens were at risk
for becoming smokers.
In a separate study, Columbia University's Renee Goodwin, PhD, MPH, shows
that a century-long increase in smoking parallels the rise in children's asthma
in the U.S.
The bottom line, says the CDC, is that there is "no risk-free level"
of exposure to secondhand smoke.
Teens and Secondhand Smoke
The CDC's new report sums up surveys of more than 740,000 teens aged 13-15
The teens completed the surveys at school from 2000 to 2007.
In the surveys, nearly half of the teens -- 47% -- reported being exposed to
secondhand smoke at home during the previous week. A similar percentage -- 48%
-- reported secondhand smoke exposure in other places during the previous
The surveys also included these two questions: "If one of your best
friends offered you a cigarette, would you smoke it?" and "At any time
in the next 12 months do you think you will smoke a cigarette?"
Teens had several options for answering those questions. If they picked any
response other than "definitely not," they were considered to be
susceptible to start smoking.
Teens who reported secondhand smoke exposure were up to twice as likely to
be susceptible to start smoking, notes the CDC in its Morbidity and
Mortality Weekly Report.
Secondhand Smoke and Asthma
Goodwin's study appears in the Annals of Allergy, Asthma &
She reports a "substantial increase" in U.S. cigarette consumption
since 1900, with cigarette use at an estimated 400 billion cigarettes in 2003,
compared with an estimated 2.5 billion cigarettes smoked in the U.S. in
The percentage of U.S. children with asthma has also risen steadily from
1980 to 1996, Goodwin notes.
Secondhand smoke is known to be a risk factor for children's asthma. Other
factors, including genetics, also affect asthma risk.
U.S. cigarette use peaked in 1981 and has been falling ever since. So if
smoking rates are dropping, why are asthma rates still rising?
"The consequences and health effects of the drastic increase in
cigarette consumption in the mid-1980s are thought to be still affecting adults
and children in the United States," writes Goodwin, adding that while the
data are not "definitive proof," they are "preliminary
evidence" of her theory.
Goodwin points out that smoking is now particularly common in low-income
groups, which also tend to have higher asthma rates.
Goodwin also notes that smoking became more common for women over the last
century, and maternal smoking before and after birth may increase children's