http://www.chron.com/cs/CDA/ssistory.mpl/front/1821346
March 17, 2003, 9:33AM
Barbecue's fatty fumes add to haze
Rice research shows fine particles matter
By DINA CAPPIELLO
Copyright 2003 Houston Chronicle Environment Writer
RESOURCES
When folks say Texans live and breathe barbecue, they really mean it.
In a study about to be published, scientists at Rice University have measured the tiny bits of polyunsaturated fatty acids created by cooking meat. These fine particles -- mixed with the diesel exhaust, car fumes and road dust that make up soot in Houston's air -- can lodge in people's lungs and contribute to the city's haze.
But while Houstonians have long joked about the "smell of money" emanating from the Ship Channel, barbecue enthusiasts don't see the humor in scientists' measuring the "fatty fumes" that are a byproduct of a favorite pastime.
"There are a lot of people who have grills at their house," said Jeff Shivers, executive director of the Texas Barbecue Association. "It's not like everybody is firing them up at the same time. There is so much other stuff in the area."
Analyzing particles in Houston's air, environmental engineer Matt Fraser of Rice University detected fatty acids among the millions of tiny organic particles that float in the city's atmosphere. The acids are released when fat drips onto hot coals and sizzles.
"It's definitely when you have an open grill. It's any process that generates meat smoke," said Fraser, whose study was recently accepted for publication in the journal Atmospheric Environment. "The compounds are specific to meat."
Come December 2004, fine particles may be subject to increased regulation in Texas if it is found that metropolitan areas such as Houston do not meet federal air quality standards for particulate matter -- what scientists call the mix of particles in the air. The area already exceeds federal guidelines for smog, and has until 2007 to come into compliance.
Research like Fraser's could be used by the state to determine which sources to eventually control.
These meaty particles -- a fraction of the width of a human hair -- are what you smell when you drive by a Burger King, steak house or barbecue joint. They are among dozens of particles, from cigarette smoke to tire wear, even cholesterol, that scientists can detect in the air using unique molecular fingerprints.
The only possible source of polyunsaturated fatty acids is meat cooking, according to laboratory tests. Scientists use other one-of-a-kind compounds to trace other pollution sources.
Fraser's analysis excluded inorganic particles, released by industry and large-scale combustion that comprise the bulk of particles in Houston's air.
"That just blows me away, because we are going to be a pollutant," said Sandy Babcock, treasurer of the Texas Gulf Coast Barbecue Association. "You think mold, tree spores ... but not meat particles."
Indeed, any suggestion that meat smoke could be a part of the hazardous particle mix is treated as downright un-Texan. Babcock's association, for example, boasts that the Lone Star state holds more than 400 competitive barbecue events every year. The organization's motto is, "Texans are born with a mission to go out and educate people about barbecue."
But Fraser isn't blaming the backyard cookout for Houston's pollution problem.
"Meat cooking is more important than wood burning, but it's less important than diesel," Fraser said. "These are trace levels. They are very low concentrations."
Fraser analyzed air samples taken from four locations between March 1997 and February 1998 for eight different sources of organic particles. Two samples were located near the heavily industrialized Houston Ship Channel. One, more representative of a suburban area, was on Bingle Road. For comparison, a fourth monitor was placed at the Galveston airport.
He found fatty particles from grilling meat in all areas. Proportionately, meat cooking was the biggest contributor only in Galveston, though the island had the lowest concentration of organic particles overall.
But unlike some of the other sources of organic particles studied -- including fuel oil, diesel- and gasoline-powered engines, road dusts and the waxes released by dead plants as they are run over -- the proportion of particles from meat cooking was constant regardless of season.
Similar air studies in Atlanta and Los Angeles have also found evidence of meat cooking. In health-conscious California, a 1996 study found fatty acids accounted for a greater percentage of the particles there than in Houston.
"There may be some difference in how many people eat meat or something, but it's really the density" of the city that determines the concentration of particles, Fraser explained.
In California, the research prompted officials to require fast-food restaurants that use chain-driven charbroilers to install ceramic filters on their exhaust vents. To meet ozone and small particle air standards by 2010, the state is considering more rigorous rules for restaurants.
"It's just part of our ongoing process here in the smog capital of the U.S. of having to go to every source of air pollution and making them do their fair share," said Sam Atwood, a spokesman for the South Coast Air Quality Management District in Southern California.
In Maryland, air permits have been required for industrial-size charbroilers and barbecue pits since 1984, said John Scherer, a public health engineer with the Maryland Department of the Environment.
A search of the Harris County database for air pollution complaints found none related to restaurants, barbecue or grilling.
Regardless, it's tough to imagine much political support for cracking down on grilling in what might be the barbecue capital of the world.
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