A child who lives in an apartment where nobody smokes has a significantly higher risk of still inhaling tobacco smoke compared to a child who lives in a detached house where nobody in the household smokes, researchers from the University of Rochester Medical Center wrote in the journal Pediatrics. A study of over 5,000 children found that 84% of kids in apartments had blood proteins indicating secondhand smoke exposure, compared to 70% of those who lived in stand-alone (detached) houses.

The authors explain that their study shows how housing type has an impact on children’s secondhand smoke exposure, beyond what the measures their parents may have taken, such as giving up smoking or going outside the building to smoke.

According to the US surgeon general, there is no safe level of tobacco smoke exposure – even a tiny amount can damage DNA. A child who inhales environmental tobacco smoke has a considerably higher risk of developing illnesses, such as SIDS (sudden infant death syndrome), asthma and some respiratory infections.

In order to gauge children’s levels of tobacco smoke exposure, the researchers measured their blood levels of cotinine. Cotinine is used as a biomarker for exposure to tobacco smoke.

Using the most sensitive cutoff for environmental tobacco smoke exposure, the researchers found that:

  • 84% of kids in apartments (multi-unit housing) had evidence of tobacco smoke exposure
  • 80% of kids in attached houses had evidence of tobacco smoke exposure
  • 70% of children in detached houses had evidence of tobacco smoke exposure

Kids who lived in apartments were found to have higher rates of exposure at every cutoff level of cotinine.

Lead author Karen Wilson, MD, MPH, said:

    “Parents try so hard to protect their children from dangers, such as tobacco smoke. It’s surprising to see these results and realize that too many parents have no control over whether their children are exposed to secondhand smoke in their own homes.”

Even after making adjustments for factors which could affect the results, such as socioeconomic status and age, kids who lived in apartments were found to have blood levels of cotinine 45% higher than those who lived in detached homes.

Some of the tobacco exposure may be due to a household member going outside to smoke and bringing back residue in their clothing, the authors write. However, they believe it is highly unlikely to explain all the difference, because the number of exposed children is considerably higher than the number of adults who smoke.

The scientists believe that the smoke has made its way through the building from apartments where people smoke to other apartments, either by seeping through walls, shared ventilation systems, or under doors, through hallways, up the stairs, etc. In their article, the authors quote other studies which showed that apartments where people smoke can contaminate non-smoking ones.

Data from the National Health and Nutrition Examination Survey 2001-2006, involving over 5,000 children, aged 6 to 18 years, were gathered and analyzed in this study. The researchers focused on determining whether housing type might be linked to smoke exposure.

Highest cotinine levels were found among children under 12 years of age, African-American, and below the federal poverty level. The authors add that prior studies had revealed a link with higher cotinine levels in children and delayed cognitive abilities.

Senior study author, Jonathan Winickoff, MD, MPH, said:

    “This study is an important piece of evidence supporting universal smoke-free multi-unit housing. More and more landlords, in all 50 states, know that they can set the smoke-free policy for their buildings, and with 80 percent of the population not smoking, market demands strongly favor smoke-free status. When landlords set a completely smoke-free policy they will enjoy lower fire risk and insurance costs, lower clean up costs between tenants, and they will be fostering a healthier home for everyone in the building.

    In general, people who smoke are very respectful of not exposing children and non-smokers to tobacco smoke in indoor environments. This research will help promote the notion that it is never acceptable to smoke indoors, even in your own unit, because the smoke get into the bodies of children in other units.

    Hopefully this research and the movement towards smoke-free housing will open up programs and opportunities for more folks to quit smoking. Promoting the use of the free quitlines in every state is a great way to facilitate these efforts.”

“Tobacco-Smoke Exposure in Children Who Live in Multiunit Housing”
Karen M. Wilson, MD, MPH, Jonathan D. Klein, MD, MPH, Aaron K. Blumkin, MS, Mark Gottlieb, JD, Jonathan P. Winickoff, MD, MPH
PEDIATRICS (doi:10.1542/peds.2010-2046d)

Written by Christian Nordqvist