The skin not the lungs get exposed to carcinogens during a barbecue
Barbecuing and grilling food can literally get under your skin.
In a study in Environmental Science & Technology, scientists have reported that skin is a more important pathway for uptake of cancer-causing compounds produced during barbecuing. They also found that clothing cannot fully protect individuals from this exposure.
Barbecuing produces large amounts of polycyclic aromatic hydrocarbons, or PAHs. These carcinogenic compounds can cause respiratory diseases and DNA mutations. Eating grilled foods is the most common source of PAHs arising from barbecuing. A previous study by Eddy Y. Zeng and colleagues had reported that bystanders near barbecues were likely exposed to considerable amount of PAHs through skin exposure and inhalation, even if they didn’t eat the grilled foods.
Building on that study, the team sought to more precisely quantify skin uptake of PAHs from barbecue fumes and particles.
Polycyclic aromatic hydrocarbons are a group of chemicals that occur naturally in coal, crude oil and gasoline, and they are also present in products made from fossil fuels, such as coal-tar pitch, creosote, and asphalt. PAHs can be released when coal is converted to natural gas. PAHs are also released into the air during burning of fossil fuels, garbage, or other organic substances.
Forest fires and volcanoes produce PAHs naturally.
PAHs are also present in tobacco smoke, smoke from wood burning, stoves and fireplaces, creosote-treated wood products, and some foods. Barbecuing, smoking, or charring food over a fire greatly increases the amount of PAHs in the food. Other foods that may contain low levels of PAHs include roasted coffee, roasted peanuts and refined vegetable oil. A variety of cosmetics and shampoos are made with coal tar and therefore contain PAHs. The PAH compound naphthalene is present in some mothballs.
PAH exposure is associated with increased incidences of lung, skin, and bladder cancers. Data for other sites is much less credible. It is difficult to attribute observed health effects in most studies to specific PAHs because most exposures are to PAH mixtures. Animal studies have shown that certain PAHs affect the hematopoietic, immune, reproductive, and neurologic systems and cause developmental effects.
In the study, volunteers were divided into groups at an outdoor barbecue to provide them with varying degrees of exposure to the food and the smoke, and their urine samples were analysed. Researchers concluded that, as expected, diet accounted for the largest amount of PAH exposure. However, the skin was the second-highest exposure route, followed by inhalation.
They said that oils in barbecue fumes likely enhance skin uptake of PAHs. The team also found that while clothes may reduce skin exposure to PAHs over the short term, once clothing is saturated with barbecue smoke, the skin can take in considerable amounts of PAHs from them. Washing clothes soon after leaving a grilling area can reduce uptake of PAHs.
