The study found that people who sat around a grill were exposed to chemicals called polycyclic aromatic hydrocarbons (PAHs) through their skin. PAHs can be produced from the burning of organic substances, such as coal, gasoline and wood; they also form when meats are cooked using "high-temperature methods," such as panfrying or grilling, according to the National Cancer Institute. Exposure to these chemicals has been linked with an increased risk of certain cancers.
But most previous studies have focused on exposure to PAHs through food or the air, rather than through the skin.
The new study, however, found that during grilling, people absorbed higher amounts of PAHs through their skin than through the air, the researchers said. Still, the greatest levels of exposure to PAHs occurred through eating the barbecued meats, the researchers noted. [9 Disgusting Things That the FDA Allows in Your Food]
It's known that exposure to smoke can put people into contact with carcinogens, including PAHs, that can be absorbed through the skin or inhaled, said Dr. Kenneth Spaeth, chief of occupational and environmental medicine at Northwell Health in Great Neck, New York, who was not involved with the study. But barbecues probably don't represent that great a risk for most people, he said.
In general, there's no level of exposure to carcinogens that's completely safe, although the lower a person's exposure, the better, Spaeth said. However, most people probably don't need to be overly worried about absorbing cancer-causing chemicals through their skin while attending a barbecue, if they don't do this frequently.
"For the average person, it's not likely to end up being a real major worry, since most people don’t engage in this activity all the time," Spaeth told Live Science. But moderation is "prudent" when it comes to how much barbecue smoke people are exposed to and how often, and how much they eat meats cooked with these high-temperature methods, Spaeth said.
In the new study, the researchers looked at data from 20 men who attended a barbecue for 2.5 hours in Guangzhou, China. The participants were divided into three groups: One group ate barbecued meats and took no special precautions to avoid exposure to smoke through the air and through their skin; a second group didn't eat any meat, but was exposed to the smoke through the air and through their skin; and a third group didn't eat any meat and wore a special mask to prevent inhalation of smoke but was still exposed to smoke through their skin.
The researchers collected urine samples from the participants before and after the BBQ and also collected air samples during the BBQ, to analyze for PAHs. The scientists also calculated estimates of each participant's uptake of PAHs through food, the air and their skin.
As the researchers expected, consuming the grilled meat was linked with the greatest level of PAH exposure. But the researchers estimated that absorption through the skin was the second-highest PAH-exposure route, followed by inhalation.
The study also found that people's clothing may lower the amount of PAHs that are absorbed through the skin over the short term. But once clothing is saturated with smoke, the skin may absorb larger amounts of PAHs, and so the researchers recommend washing clothes soon after leaving the grilling area to reduce exposure.
Spaeth said he agreed that wearing clothes like long sleeves and long pants would be one way to reduce exposure to PAHs at a BBQ. In addition, the type of fuel a person uses can affect the amount of PAHs produced, with propane producing much lower doses of PAHs compared with charcoal, he said. Finally, barbecuing in a well-ventilated area, such as outdoors as opposed to inside a tent or confined area, could lower exposure to PAHs, Spaeth said.
The study was published today (May 23) in the journal Environmental Science & Technology.
Original article on Live Science.
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Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.