Exposure of the skin to third-hand smoke, the smoke that remains in homes after cigarettes are put out, could increase the risk of triggering skin diseases, such as contact dermatitis and psoriasis, according to a new study.
- Primary smoke is that which the smoker inhales directly.
- Second-hand smoke is released between each puff when the cigarette continues to burn: it is responsible for passive smoking.
- Tertiary smoke, which we are talking about in this study, is the microparticles that remain in suspension in the air and are then deposited in dust and on interior surfaces in a place where someone has smoked before.
A cigarette, once consumed, can still have adverse health effects. Indeed, the polluting particles remain in suspension in the air and then settle on the interior surfaces. This is called third-hand smoke, which, even long after the cigarette has been extinguished, remains trapped in the hair, on the skin, fabrics, carpets, furniture or the walls of a house. .
A previous study had found that it could linger in homes for years, causing potentially harmful exposure for smokers and non-smokers alike.
Contact dermatitis, psoriasis: third-hand smoke increases the risks
This time, a team led by researchers from the University of California found that acute skin exposure to third-hand smoke can increase the risk of triggering skin diseases, such as contact dermatitis and psoriasis. Their studypublished in the journal eBioMedicineis the first to focus on the impact of third-hand smoke on humans exposed through the skin.
“We found that exposure of human skin to thirdhand smoke initiates inflammatory skin disease mechanisms and elevates urinary biomarkers of oxidative damage, which could lead to other diseases, such as cancer, heart disease and atherosclerosis”said one of the authors of the study, the doctor of biology Shane Sakamaki-Ching, in a communicated. “Alarmingly, acute dermal exposure to third-hand smoke mimics the harmful effects of active smoking”he added.
The clinical study took place at UC San Francisco with 10 healthy, non-smoking volunteers between the ages of 22 and 45. For three hours, each of them wore clothing soaked in cigarette smoke and walked or ran on a treadmill for at least 15 minutes per hour to produce sweat and increase the absorption of smoke through the skin. skin. The participants were unaware that the clothing was impregnated with third-hand smoke. Blood and urine samples were then taken from each volunteer at regular intervals to identify protein changes and markers of oxidative stress caused by the effects of third-hand smoke. The results were compared with those of a control group.
There is a lack of knowledge about the effects of smoke exposure
The exposure to third-hand smoke, to which all 10 participants were subjected, was relatively brief and did not cause any visible skin changes. Nevertheless, blood molecular biomarkers associated with early activation of contact dermatitis, psoriasis and other skin conditions were elevated. Elevations in biomarkers were maintained even after exposure ceased. Cigarette smokers showed this same elevation. The researchers explained that the skin is the largest organ in the body to come into contact with third-hand smoke and therefore may be the most exposed.
“There is a general lack of knowledge about human health responses to exposure to third-hand smoke”explains Talbot, one of the authors of the study. “If you buy a used car that was previously owned by a smoker, you are exposing yourself to a certain risk to your health. If you go to a casino that allows smoking, you are exposing your skin to third-hand smoke. the same if you stay in a hotel room that was previously occupied by a smoker”he adds.
“Our results can help physicians diagnose patients exposed to third-hand smoke and develop regulatory policies addressing the remediation of indoor environments contaminated by these smokes”the study authors said.
Next step for the team of researchers: to analyze the residues left by electronic cigarettes in contact with human skin. They also plan to assess a larger number of individuals with longer periods of dermal exposure to third-hand smoke.