Studies report new risks to teens from secondhand smoke | Science News for Students

Studies report new risks to teens from secondhand smoke

The pollution seems to boost risk of subtle immediate harm — then early death from lung disease as adults
Oct 5, 2018 — 6:45 am EST
a lit cigarette resting on an ashtray, smoke is rising from the cigarette

Lingering cigarette smoke can be inhaled by others. Teens who breathe this in may become more susceptible to disease now, then face a higher risk in adulthood from lung disease.


No surprise: Smoking is bad for your health. But even people who never touch a cigarette can be harmed by cigarette smoke. They merely have to inhale the airborne pollutants exhaled by a smoker. That so-called secondhand smoke can linger in the air for days. Teens who can’t avoid breathing it in may develop coughing and trouble breathing. But even those who don’t may still suffer, a new study finds. And that’s not the worst of it. Another study found that in teens exposed to that smoke for years, far more serious lung disease may develop.

Some 9.6 million U.S. teens and preteens are exposed to secondhand smoke, which can aggravate asthma. That’s a lung disease that can make it hard to breathe. Most secondhand-smoke studies focus on teens with asthma. But Ashley Merianos, a tobacco researcher at the University of Cincinnati in Ohio, wondered if this pollution might hurt other kids, too. To find out, her team decided to look at overall sickness rates in these kids. They also tracked their school attendance rates.

The researchers used data from a national survey known as PATH. (It stands for Population Assessment of Tobacco and Health.) Every year since 2011, the U.S. Department of Health and Human Services has surveyed people 12 and up about the effects of tobacco on their health. Its findings help guide government policies to protect public health.

Merianos’ team focused on PATH data from 2014 and 2015 for kids ages 12 to 17. That covered 7,389 adolescents. Each kid had been asked if they lived with someone who smoked. They also were asked how much time they were exposed to smoke in a typical week.

Other questions asked whether they generally felt short of breath, or did they have a dry cough at night. Each kid reported whether they visited the emergency room that year, and if so, how often. Finally, each participant estimated how often they missed school over the past year for medical reasons.

Many things affect our health. So linking effects to particular causes is not easy. Yet researchers must try to account for this when designing a study. Here, Merianos’ team took one step by excluding any teens with asthma. They also excluded those who had smoked cigarettes within 30 days of taking the survey. That helped the researchers home in on teens who had been generally been healthy.

Some of these kids reported no regular exposure to secondhand smoke. And compared to them, those who lived with smokers or encountered secondhand smoke at least an hour each week were more likely to report health issues. During or after exercise, for instance, they were more likely to suffer from shortness of breath and wheezing. They also reported more days off sick from school.

The team published its findings in the August Pediatrics.

Long-term consequences

Ryan Diver works for the American Cancer Society (ACS) in Atlanta, Ga., where he usually studies the causes of cancer. But he was intrigued by the report’s finding that teens living with smokers are likely to have poor lung function. He suspected that inhaling smoke as a kid might lead to lifelong lung problems. So his team decided to mine data from a large study of adults to see if there were any signs this might be true.

These researchers used data from a large ACS cancer-prevention study. Roughly 70,000 people between the ages of 50 and 74 took part. None had ever smoked. The study took place at two different times. In 1992, the volunteers reported if they had ever been exposed to smoke regularly as a child. After 22 years, the survey look at the recruits' health. About one-third had died. The study noted the reported cause.

Diver’s team then looked at whether certain causes of death were more likely among those people who had been exposed to secondhand smoke as children. And they found such people were more likely to have died from lung disorders. The researchers published their findings in the August American Journal of Preventive.

A 2014 health report by U.S. government had suggested that secondhand exposure to smoke could have long-term adverse effects, notes Merianos. The data by Diver’s team now supports that suspicion, she says.

Together, the new studies suggest that passive smoking may hurt teens’ health in multiple ways. Adults should avoid smoking around adolescents, says Merianos. And for teens, not smoking is a good first step. But it may also be important to limit time around peers and others who do light up.

Power Words

(more about Power Words)

adolescent     Someone in that transitional stage of physical and psychological development that begins at the onset of puberty, typically between the ages of 11 and 13, and ends with adulthood.

asthma     A disease affecting the body’s airways, which are the tubes through which animals breathe. Asthma obstructs these airways through swelling, the production of too much mucus or a tightening of the tubes. As a result, the body can expand to breathe in air, but loses the ability to exhale appropriately. The most common cause of asthma is an allergy. Asthma is a leading cause of hospitalization and the top chronic disease responsible for kids missing school.

cancer     Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.

data     Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

develop     To emerge or come into being, either naturally or through human intervention, such as by manufacturing. (in biology) To grow as an organism from conception through adulthood, often undergoing changes in chemistry, size and sometimes even shape.

disorder     (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.

emergency room     Also known as the ER. It's that part of the hospital where doctors initially attend to the immediate medical needs of accident victims and others who need critical care.

function     A relationship between two or more variables in which one variable (the dependent one) is exactly determined by the value of the other variables.

pediatrics     A field of medicine that has to do with children and especially child health. A doctor who works in this field is known as a pediatrician.

peer     (noun) Someone who is an equal, based on age, education, status, training or some other features. (verb) To look into something, searching for details.

policy     A plan, stated guidelines or agreed-upon rules of action to apply in certain specific circumstances. For instance, a school could have a policy on when to permit snow days or how many excused absences it would allow a student in a given year.

pollutant     A substance that taints something — such as the air, water, our bodies or products. Some pollutants are chemicals, such as pesticides. Others may be radiation, including excess heat or light. Even weeds and other invasive species can be considered a type of biological pollution.

population     (in biology) A group of individuals from the same species that lives in the same area.

recruit     (noun) New member of a group or human trial. (verb) To enroll a new member into a research trial. Some may receive money or other compensation for their participation, particularly if they enter the trial healthy.

secondhand smoke     The gas and smoke particles emitted out of the burning end of a cigarette in addition to the particles exhaled by smokers. This pollution can be toxic and hand into the air (where it is available to be breathed in) for hours. Government scientists report that this secondhand smoke may contain up to 7,000 different chemicals, including hundreds that may be toxic (70 of which can cause cancer). According to the U.S. Centers for Disease Control and Prevention, since 1964, some 2.5 million nonsmokers have died from exposure to secondhand smoke.

smoke     Plumes of microscopic particles that float in the air. They can be comprised of anything very small. But the best known types are pollutants created by the incomplete burning of oil, wood and other carbon-based materials.

smoking     A term for the deliberate inhalation of tobacco smoke from burning cigarettes or cigars.

society     An integrated group of people or animals that generally cooperate and support one another for the greater good of them all.

survey     (v.) To ask questions that glean data on the opinions, practices (such as dining or sleeping habits), knowledge or skills of a broad range of people. Researchers select the number and types of people questioned in hopes that the answers these individuals give will be representative of others who are their age, belong to the same ethnic group or live in the same region. (n.) The list of questions that will be offered to glean those data.

tobacco     A plant cultivated for its leaves, which many people burn in cigars, cigarettes, and pipes. Tobacco leaves also are sometimes chewed. The main active drug in tobacco leaves is nicotine, a powerful stimulant (and poison).

wheezing     (v. wheeze) Chest sounds associated with labored breathing. They can sound like a whistling or rattling, and develop when something obstructs some of the air passages.


Journal: A.L. Merianos et al. Adolescent tobacco smoke exposure, respiratory symptoms, and emergency department usePediatrics. Vol.142, August 2018. doi: 10.1542/peds.2018-0266.

Journal: W.R. Diver et al. Secondhand smoke exposure in childhood and adulthood in relation to adult mortality among never smokersAmerican Journal of Preventive Medicine. Vol. 55, August 2018, p.345. doi: 10.1016/J.AMEPRE.2018.05.005.

Report: U.S. Department of Health and Human Services et al. Population assessment of tobacco and health (PATH) study [United States]. Ann Arbor, MI: Inter-university Consortium for Political and Social Research. May 1, 2018. doi: 10.3886/ICPSR.36498.v7.

Journal: E.E. Calle et al. The American Cancer Society Cancer Prevention Study II nutrition cohort: rationale, study design, and baseline characteristics. Cancer. Vol. 94, January 2002, p. 500. doi: 10.1002/cncr.10197.

Report: U.S. Department of Health and Human Services. The health consequences of smoking—50 years of progress: a report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. November 27, 2014.