XIAMEN île de Gulang Yu

It’s Memorial Day weekend, and that means it’s time to break out the barbecue and toss some steaks, chicken wings, cow stomachs, and pork ribs on the grill … as long as you haven’t gotten a tick-borne meat allergy, of course. And while barbecuing is a great way to get people to gather, as with anything fun, there are some potential health concerns.

In a paper published Thursday in the journal Environmental Science & Technology, a team of researchers at Jinan University in Guangzhou, China, and Peking University in Beijing showed evidence that a cook’s exposure to carcinogenic (cancer-causing) chemicals produced while barbecuing is a little more complicated than previously thought. When an organic substance is burned incompletely, it produces something called polycyclic aromatic hydrocarbons. PAHs, therefore, are produced when we barbecue meat. While exact numbers are hard to nail down, studies have shown that breathing and eating PAHs increases humans’ cancer risk. But in the new study, researchers found that exposure is actually much greater through the skin than the lungs.

barbecuing cancer exposure
This fun little graphic shows the different ways that polycyclic aromatic hydrocarbons can get into the human body.

To conduct the study, researchers basically threw a barbecue: They gathered 20 men between the ages of 22 and 25 to barbecue on charcoal grills outside. They divided them into three groups to control how they were exposed to PAHs: One group breathed the smoke, got it on their skin, and ate the food that was grilled. The second group was exposed but didn’t eat the food. The third group wore a hood with an air tank and didn’t eat the food, so only their skin got exposed. These last two groups only ate boiled foods, sadly.

Researchers collected urine samples from the participants before and after the barbecue and found that, while eating barbecued food still exposed participants to the highest levels of PAHs, dermal and inhalation exposures were significant. Interestingly, they found that exposure levels were greater through the skin than through the lungs. “Oils in BBQ fumes can probably enhance the dermal absorption of PAHs,” the study’s authors write.

Fortunately, the researchers found that the levels of PAHs in the volunteers’ urine fell back to baseline levels after about 24 hours. This study doesn’t mean that your barbecue will give you cancer, but it does mean that you’re being exposed to some amount of carcinogenic chemicals just by gathering around the grill.

More research is necessary to nail down exactly what the hazard of being exposed to PAHs is, since there isn’t a whole lot of data available, but for now, the best advice is to enjoy your barbecue and maybe just don’t grill out every single day.