Studies on Tobacco Exposure and Children

Secondhand Smoke Exposure Increases School Absences

In September 2011, a nationwide study published online in Pediatrics concludes that children who live in households where they are exposed to tobacco smoke miss more days of school than do children living in smoke-free homes. These children have higher rates of respiratory illnesses that can be caused by second-hand smoke and details the probable economic costs of their increased school absence, according to the report's investigators at Massachusetts General Hospital (MGH). According to the lead researcher, "among children ages 6 to 11 who live with smokers, one quarter to one third of school absences are due to household smoking." The authors note that one-third of U.S. children live with at least one smoker, and more than half of those aged 3 to 11 have detectable levels of a blood marker for tobacco exposure.

Secondhand smoking has been shown to increase incidence of ear infections and several respiratory conditions, and school absenteeism is an accessible measure of serious illness in children. Of the 3,087 children whose information was analyzed for this study, more than 14 percent lived in a home with at least one person who smoked in the house - 8 percent lived with one household smoker and 6 percent with two or more - which represents 2.6 million children nationwide. Children living with one in-home smoker had an average of 1.06 more days absent, and those living with two or more had 1.54 more days absent than did children living in homes where no one smoked indoors. Since the absentee levels we report are averages, there are probably kids who miss much more school because they live with smokers than our study found. The authors also found that "on a national basis these absences result in $227 million in lost wages and time for caregivers or their employers." Read press release.

Asthma Triggers

An August 2010 study, Influence of indoor factors in dwellings on the development of childhood asthma, published in the 2011 International Journal of Hygiene and Environmental Health, concluded:

"Since exposure to Environmental Tobacco Smoke (ETS) is a likely cause for the onset of asthma in childhood, we conclude that there is a strong need to prevent infants and children from breathing air which is contaminated with tobacco smoke. There is no need for more research. The evidence of an adverse health effect of the exposure to ETS is sufficiently strong to propose such actions."

Increased Blood Pressure

A study published in the January 2011 journal Circulation found that secondhand smoke increases blood pressure in children as young as 4 years old, putting them at risk for a lifetime of cardiovascular problems. The Heidelberg University of Germany study examined 4,000 German children, according to author Dr. Giacomo Simonetti. Children of parents who smoked were 31% more likely to have blood-pressure readings in the top 15% of the entire group, even after adjusting for other risk factors (obesity, parents with high blood pressure). That is significant, because elevated blood pressure in youth can increase an individual's chance of developing serious cardiovascular problems at early ages. "Passive smoking remains a risk factor independent [of] the other risk factors," said Dr. Simonetti. Read a news article about it and the abstract from the study.

Secondhand smoke Biomarkers in Children

A study published in the January 2011 journal Pediatrics by the University of Rochester Medical Center and MassGeneral Hospital shows significant evidence of tobacco smoke exposure in the blood of children from smokefree apartments who live in non-smokefree multi-unit housing. Read the press release announcing this study. Read the study abstract. Learn more from our webpage on Smokefree Multi-Unit Housing.

A Harvard School of Public Health study, published online in the June 7, 2010 issue of Pediatrics, found that children and adolescents living in non-smoking homes in counties with laws promoting smoke-free public places have significantly lower levels of a common biomarker of secondhand smoke exposure than those living in counties with no smoke-free laws. Read the press release. Read the study abstract.

Mental Illness and Secondhand Smoke

A study published April 2011 in Archives of Pediatrics and Adolescent Medicine found a correlation between secondhand smoke exposure and mental illness in children, including major depressive disorder, generalized anxiety disorder, panic disorder, attention-deficit/hyperactivity disorder, and conduct disorder. Read the study abstract and an April 5, 2011 news article from the Los Angeles Times.

Smoking during Pregnancy and Around Infants

Nonsmoking women who breathe secondhand tobacco smoke during pregnancy increase their risk of stillbirth, major birth defects, and other harms to their babies, according to a meta-analysis published March 7, 2011 in Pediatrics. Four of the observational studies found a 23% increased risk of stillbirth with tobacco smoke exposure during pregnancy. Seven of the studies found that pregnant women exposed to second hand smoke were also 13% more likely give birth to a child with congenital malformations. Read a Medpage news article.

New Infants exposed to secondhand smoke are at an increased risk for SIDS. Read the abstract from a study published in the Tobacco Control Journal about infant mortality as it relates to decreasing exposure to secondhand smoke. Read a publication from an Australian organization, SIDS and Kids, chocked full of information to minimize the risk of SIDS for your infant:

Last update: 2/3/12