Tobacco Toxins That Harm Nonsmokers

by Carole Jackson>, Bottom Line Health

Ever step inside a hotel room and know instantly that someone recently smoked in it?

Or hop into a rental car and need to roll down the windows immediately to air out the stench of cigarettes?

Or maybe you occasionally get a “tobacco-y” whiff from the clothes or hair of a smoker who lives below you or in the condo next door.

So-called “thirdhand” smoke is the contamination that remains after a cigarette has been extinguished. And I’m sorry to tell you that it’s also dangerous, just like firsthand smoking and secondhand smoke—and why you need to avoid it…


Believe it or not, the quintessential experiment proving the hazards of thirdhand smoke was published in Cancer Research way back in 1953. Researchers at the (then-called) Sloan-Kettering Institute of the Memorial Center for Cancer and Allied Diseases in New York collected cigarette smoke in a beaker and then gathered the residue that clung to the glass. They mixed the residue with a solvent and painted it on the backs of some mice…on other mice (the control group), they painted solvent alone. Researchers found that 59% of the mice exposed to tobacco residue developed skin lesions, and most of those mice went on to develop cancer. In contrast, none of the control mice developed skin lesions or cancer.

Now fast-forward to today. Sure, we’re living in a time when smoking is banned from most public places in the US, but, unfortunately, many homes, apartment buildings, hotel rooms and cars are still heavily contaminated, I learned recently from Jonathan Winickoff, MD, MPH, a pediatrician and professor of pediatrics at Harvard Medical School in Boston and one of the country’s top researchers on tobacco and health.

Some of these spaces are being smoked in still…others used to be smoked in…and all can hurt your health.


Thirdhand cigarette smoke adheres to all surfaces and remains there even after a butt is stubbed out. “It’s surprisingly dangerous because it reacts with other compounds in the environment and with itself to create new tobacco-specific nitrosamines, compounds that are highly carcinogenic,” said Dr. Winickoff.

This thirdhand smoke is, unfortunately, almost impossible to clean off most surfaces, though you’ll have more luck with glass surfaces than with porous ones, such as wallboard. Usually, it just sticks around until someone comes into contact with it.

There are three ways that humans can come into contact with thirdhand smoke…

  • Through breathing. The compounds can be reemitted into the air, so it’s possible to inhale them into your lungs.
  • Through touch. Compounds can enter the body through the skin—just by touching a wall or lamp or using an armrest, for example.
  • Through ingestion. The microscopic compounds can settle on everything from dishware to food, making it possible for us to unknowingly eat them.


People of any age can suffer various health consequences from any amount of exposure to thirdhand smoke, though children, in particular, are more likely to come into contact with the toxins and are more likely to be negatively affected by them.

Children breathe at faster rates than adults, so when thirdhand smoke is present, the little ones’ respiratory exposure is much higher. Also, they tend to touch everything and move around surfaces like mops, which increases their skin exposure. Plus, they ingest twice the amount of house dust as the average adult, said Dr. Winickoff.

Since a child usually weighs less than what an adult weighs, exposure will impact a kid’s body more. And because their bodies and brains are still developing, the exposure can have measurable effects. Studies have found that children exposed to thirdhand smoke have much higher blood levels of cotinine, which is a breakdown product of nicotine, compared with children who are not exposed to contaminated environments. “High cotinine levels have been associated with developmental delays and lower reading and math scores,” said Dr. Winickoff. “Plus tobacco smoke exposure—it can be hard to tease out the effects of secondhand and thirdhand smoke—is now a leading cause of Sudden Infant Death Syndrome.”


So if you or someone around you still smokes, this is obviously another good reason to quit—and another good reminder that smoking doesn’t just harm the person who has the cigarette in his or her mouth. For more information on how to quit, click here.

If you’re not a smoker, do everything you can to avoid thirdhand smoke. Try to live in a building that is smoke-free, because even if there is just one smoker around—even in another apartment—smoke moves freely in the air through ductwork or out one window and into another and can affect everyone. Reject a stinky-smelling hotel room or rental car, and ask the company for a replacement. And if a smoker (even one who is not smoking at the moment) steps into an elevator with you, step out of the elevator and take the next one. Is this inconvenient? Sure, but your good health is worth the extra hassle.

Source: Jonathan Winickoff, MD, MPH, pediatrician and associate professor, department of pediatrics, Harvard Medical School, Boston, and immediate past chair of the American Academy of Pediatrics Tobacco Consortium. He has drafted tobacco control policies for the American Medical Association and other organizations.