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KNOXVILLE, Tenn. — Cities and states can fight air pollution more effectively using a new University of Tennessee method of estimating automobile emissions.

Dr. Arun Chatterjee, UT-Knoxville civil and environmental engineering professor, said the UT model more accurately estimates automobile emissions by more closely factoring engine starting and running temperatures into the formula.

Cities and states are required to report automobile emissions estimates to the U.S. Environmental Protection Agency and form a plan to reduce emissions if totals exceed federal limits, he said.

Automobile engine emissions vary greatly depending on engine temperature; the warmer the engine, the fewer pollutants it releases, Chatterjee said.

How long the car has been running, outside temperature, length of time since the car ran last and other factors determine engine temperature and affect emissions. Current methods to estimate emissions don’t accurately account for these factors, Chatterjee said.

The UT model takes these data into consideration to provide more accurate estimates, Chatterjee said. Increased accuracy would enable city and state agencies to take more effective steps to control pollution, he said.

The model was developed under a contract with the state of California, which has the highest amount of automobile emissions of any state, Chatterjee said. California officials plan to use the UT model in their vehicle emission analysis, he said.

“This new model can help areas, especially those that exceed EPA limits for air pollution, form more exact strategies to prevent or reduce air pollution from automobile emissions,” Chatterjee said.

A UT report on the new model recently was recognized by the Transportation Research Board as one of the nation’s top transportation research papers.

The UT model was developed by Chatterjee, Dr. Terry Miller, a UT-Knoxville civil and environmental engineering professor, and Dr. Mohan Venigallo, who recently received a Ph.D. in civil and environmental engineering at UT-Knoxville.

Contact: Dr. Arun Chatterjee (423-974-7714)

Dr. Terry Miller (423-974-7731)