For years, women have been warned not to smoke while pregnant, and to stay away from other people who were smoking to avoid breathing in second-hand smoke. Now researchers at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed) have added another warning for pregnant women: stay away from third-hand smoke to help protect their unborn children’s lungs.
Smoke, whether from cigarettes, cigars, or pipes, is known to contain chemicals that can damage lungs and cause cancer. People who smoke draw these dangerous chemicals directly into their lungs. Second-hand smoke is the left-over smoke floating in the air around a smoker. It may come directly from the cigarette, or may be in the air exhaled by a smoker. Second-hand smoke also contains nicotine and other cancer-causing chemicals.
Third-hand smoke is the residue of nicotine and other toxins from smoke that become trapped in the walls, ceilings, and floors of rooms where smoking took place. Research has shown that third-hand smoke can remain for up to two months after smoking took place. When this dusty residue is disturbed, it can become airborne and again pose a threat to anyone who breathes it in.
Researchers at LA BioMed concluded that third-hand smoke inhaled by a pregnant woman can be as serious for the development of an unborn baby’s lungs as breathing in second-hand smoke is to an infant or toddler. One of the authors of the BioMed study, Dr. Virender Rehan, called third-hand smoke a "stealth toxin" because it can be left behind by a smoker and cause damage to someone who doesn’t know it is there. He said, "Pregnant women should avoid homes and other places where third-hand smoke is likely to be found to protect their unborn children against the potential damage these toxins can cause to the developing infants’ lungs."
Damage caused by third-hand smoke during lung development can cause asthma and other respiratory problems that will last a lifetime. This study also shows that the strategy of going outside to smoke is not effective for protecting an unborn baby since third-hand smoke will also cling to clothing and be carried back into the house.