Restaurant emissions contribute to pollution

Researchers from the University of Minnesota found pollution from commercial cooking in restaurants is prominent.

Brent Renneke

Researchers from the University of Minnesota found pollution from commercial cooking in restaurants is prominent, and current methods to reduce it are less than effective. Dr. Thomas Kuehn, professor in the department of mechanical engineering, said commercial cooking creates emissions that are significant contributors to pollution, and these emissions are harder to control than previously thought. âÄúCompared to other emission sources, it is quite large,âÄù Kuehn said. âÄú[The emissions] are sometimes several percent of the food product being cooked.âÄù Using a laboratory equipped with a full kitchen, Kuehn said he was able to test a number of different cooking appliances for emission rates. Conveyor broilers, which are used in a number of fast food restaurants, created nearly 25 pounds of emissions in the exhaust duct per 1,000 pounds of hamburger cooked. A clamshell griddle, which is similar to the George Foreman Grill, only produced about 10 pounds in the exhaust duct per 1,000 pounds of hamburger cooked. Kuehn said the variance in the amount of emissions is dependent on the food and how that food is being cooked. Foods with a high fat content have higher emissions, according to Kuehn. âÄúIf you are cooking hamburgers compared to cooking vegetables, the hamburger is going to have a higher emission,âÄù Kuehn said. Also, Kuehn said a cooking appliance like a broiler, which cooks at a high temperature, contributes more emissions than something that cooks at a lower temperature. Dr. Bernard Olson, senior research associate in the Department of Mechanical Engineering, said appliances like a wok using peanut oil produced about 55 pounds of emissions in the exhaust hood per 1,000 pounds of chicken cooked. âÄúThe percentage of the food product emitted was pretty amazing,âÄù Olson said. âÄúThere is a lot coming off the food that is just going into the air.âÄù Along with analyzing the emissionsâÄô physical characteristics, experiments to determine the chemical composition were taken, according to Dr. Deborah Gross, associate professor of chemistry at Carleton College. With cooking methods that used high temperatures, Gross said the experiments revealed the presence of polycyclic aromatic hydrocarbons, a compound that is potentially carcinogenic. Tim Farrell, chemical engineer and independent consultant, said this is of particular risk to people who repeatedly cook using higher-heating methods. âÄúThere is large risk to kitchen workers, and even people who cook in their homes,âÄù Farrell said. Particles emitted from commercial cooking can become lodged in the deep lung area and cause various health problems, according to Kuehn. Kuehn said restaurants that may contribute to this risk are visible by both sight and smell. Although the smell of grilled hamburger may seem harmless to a passerby, Kuehn said it is direct evidence of the restaurantâÄôs pollution contribution. Also, the particles emitted can condense on the roof of the restaurant, as well as erode the surrounding asphalt, according to Kuehn. âÄúIn a perfect world, you wouldnâÄôt see or smell anything when you walk by a restaurant,âÄù Kuehn said. Although other industrial practices, like factories, have caused more pollution, these industries have received the attention necessary to address the problem, according to Farrell. âÄúLots of industrial practices that were dirtier than cooking have been cleaned up,âÄù Farrell said. âÄúCooking has been largely ignored.âÄù Efforts to utilize KuehnâÄôs research have begun in California, where cooking practices are regulated in areas of Los Angeles and San Francisco. Olson said it is common practice for regulations like this to start in California before spreading out to the rest of the United States. âÄúOnce it is established there, I believe that it will move throughout the rest of the country,âÄù Olson said. Along with increased regulations, technological advancements would be necessary to have increased filtration systems, according to Olson. Olson said typical filters would require constant replacing. âÄúThe technology is going to take some time to be able to remove a lot of particulate and vapor,âÄù Olson said. Fuller said the research gives manufacturers of this technology the information they need, which they would otherwise lack the resources to find out. âÄúIt has really advanced the state of practice in this industry,âÄù Fuller said. âÄúIt is enabling innovation all across the industry.âÄù