As a kid growing up in the 90s, I bore witness to the swift downfall of cigarette smoking culture in the US. First, smoking sections in restaurants (remember those?) disappeared seemingly overnight; within a few years, even bars and public parks, once havens of the nicotine-addicted, were cleaned up of even the barest whiff of a cig. Much of this change was due to the newly discovered dangers of secondhand smoke, an idea none of us had really considered before it was targeted in a series of public health campaigns. As it turns out, “involuntary smoking” is much less dangerous than the powers-that-be thought—unless, that is, you’re referring to the carcinogen-laden smoke you’re likely absorbing through your skin each time you’re in the vicinity of a summer cookout.
According to a report published on Wednesday in the journal Environmental Science & Technology, the type of secondhand smoke that grillers everywhere need to worry about now is the kind that wafts up off of your loaded Weber each time you fire it up for a (previously) relaxing barbecue sesh. Loaded with potentially cancer-causing compounds called polycyclic aromatic hydrocarbons (PAHs), the meat-tinged smoke can be absorbed through the skin—and not just the skin of the grillmaster, but even BBQ guests in the area who aren’t even eating what comes off the grill.
The danger of PAHs in grilled meats has been a concern since the late 60s, when a series of studies established a link between a higher incidence of bowel and stomach cancers in lab rats fed a diet high in grilled and charred meats. Even the potential danger of the inhalation of grill smoke has been looked at before—but the recent study, conducted at Jinan University in Guangzhou, China by lead researcher Dr. Eddy Y. Zeng, is the first to examine how the carcinogenic compounds can be absorbed by the skin.
"Diet has been recognized as the most predominant exposure route, whereas inhalation is inevitable and constant. Thus, many studies have focused on dietary ingestion and inhalation in human health risk assessment," the authors of the study write. "Dermal absorption of the general population to fumes and related health risk seem to have been largely overlooked."
To obtain the data, the researchers divided 20 participants into groups at an outdoor barbecue, exposing them to food and smoke at varying degrees. The researchers then measured PAH levels in participants’ urine. As expected, those that ate the grilled food demonstrated the highest levels of PAHs. But researchers found that skin was the second-highest exposure route for the compounds, even more so than inhalation.
Apart from the digestive system, our skin is the part of the body that most consistently comes into contact with the outside world, and, since it’s porous, it absorbs whatever you put on it. That’s why the medical community—especially the “alternative” medical community—has long encouraged us to carefully choose skincare products free of harmful chemicals. But the Chinese study demonstrates that even airborne compounds can be a threat to the skin. The researchers noted that while clothes can act as a short-term barrier to BBQ smoke, they quickly become saturated in PAHs and can act as a “persistent exposure source” if they’re not changed.
So as you backyard-hop this summer, you might want to stay far, far away from whichever buddy is manning the grill. Or, you know, just pull a Beyoncé and change your outfit every half hour or so. Tell them it’s in the name of science.