Topeka ? A Kansas University Medical Center professor today said he is upset his picture was used in a newspaper advertisement that criticizes coal-fired power plants.

Dr. Steven Simpson, an associate professor in the pulmonary and critical care medicine department, said when he agreed to allow his image to be used he didn’t know that the ad was financed by a natural gas company.

“I would not have done that at the behest of a natural gas company,” Simpson said. “That’s a whole different ball of wax.”

The company — Chesapeake Energy Corp., headquartered in Oklahoma City — has launched a multi-media campaign criticizing coal-fired plants, such as the ones proposed in western Kansas, which were recently rejected by state officials.

Nowhere on the ads does it mention that Chesapeake has paid for them. The full-page ads have run in several newspapers. The campaign also includes television ads.

Simpson said he agreed that coal-fired plants lead to health problems but that he didn’t want to get involved in a fight between coal interests and natural gas interests.

He said he was asked to allow his picture to be used in the ad by the American Lung Association of Central States, and assumed the ads were being sponsored by health groups. A call to the association wasn’t immediately returned.