Last year I wrote about the health risks of using high heat when grilling. New reports tell us that our skin may absorb toxins from the grill fumes.

The aroma from grilling meats on high heat can produce cancer-causing compounds called polycyclic aromatic hydrocarbons (PAHs).  In a report on the National Cancer Institute’s website explains that both heterocyclic amines (HCAs) and polyclic aromatic hydrocarbons (PAHs) are chemicals formed when muscle meat, including beef, fish, or poultry, is cooked using high-temperature methods such as pan frying or grilling directly over an open flame. In laboratory experiments, HCAs and PAHs have been found to be mutagenic. That is they cause changes in DNA that may increase the risk of cancer.

HCAs and PAHs become capable of damaging DNA only after they are metabolized by specific enzymes in the body, a process called “bioactivation.” Studies have found that the activity of these enzymes, which can differ among people, may be relevant to the cancer risks associated with exposure to these compounds.

HCAs are formed when amino acids (the building blocks of proteins), sugars, and creatine or creatinine (substances found in muscle) react at high temperatures. PAHs are formed when fat and juices from meat grilled directly over a heated surface or open fire drip onto the surface or fire, causing flames and smoke. The smoke contains PAHs that when adhere to the surface of the meat. PAHs can also be formed during other food preparation processes, such as smoking of meats.

HCAs are not found in significant amounts in foods other than meat cooked at high temperatures. PAHs can be found in other smoked foods, as well as in cigarette smoke and car exhaust fumes.

A study from China suggests letting your skin come into contact with PAHs when you grill food is even more harmful than just savoring the aroma. Though eating barbecued meats is the most common source of exposure, just standing near a grill and breathing PAH-contaminated air can be risky, previous studies have shown. And clothing won’t fully protect you against them either.

Clothes can help protect you from the smoke, but only for a short period, the researchers noted in a journal news release. Once fabrics become saturated with contaminated smoke the skin can absorb high PAH levels.

To reduce your exposure to these toxic compounds, the researchers recommend laundering clothes immediately after you are around a grill.

For the latest study, published May 23 in Environment Science & Technology, a team led by Eddy Y. Zeng at Jinan University closely examined skin exposure to PAHs from barbecue fumes and particles.

The researchers divided volunteers into groups based on various levels of exposure to grilled foods and smoke.

Urine samples revealed the greatest PAH exposure came from eating grilled foods, but skin contact was in second place, followed by inhalation of barbecure fumes.

Numerous studies have used detailed questionnaires to examine participants’ mean consumption and cooking methods. Researchers found that high consumptin of well-done, fried, or barbecured meats was associated with increased risk of colorectal, pancreatic, and prostate cancer.

Even though no specific guidelines for HCA/PAH consumption exist, concerned individuals can reduce their exposure by using several cooking methods:

• Avoid direct exposure of meat to an open flame or a hot metal surface and avoiding prolonged cooking times (especially at high temperatures) can help reduce HCA and PAH formation.
• Using a microwave oven to cook meat prior to exposure to high temperatures can also substantially reduse HCA formation by reducing the time that meat must be in contact with high heat to finish cooking.
• Continuously turning meat over a high heat source can substantially reduce HCA formation compared with just leaving the meat on the heat source without flipping it often.
• Removing charred portions of meat and refraining from using gravy made from meat drippings can also reduce HCA and PAH exposure.