While many of us keep a close watch on the mercury rising...Dave Merritt has his attention focused elsewhere.

"Ozone levels may reach an unhealthy level-especially for older adults, young children, people with asthma, and for people performing vigorous healthy activities," he explains.

In response, Dane county designated today as the year's first Clean Air Action Day.

"A Clean Air Action Day also lets people know of simple actions they can take to improve the air that all of us breathe," says Merritt, who adds area residents are encouraged to avoid using gas in both vehicles and lawn mowers, and to reduce their use of air conditioners and electricity.

"These voluntary measures that we are recommending will help ensure that Dane County's air stays clean and that we do not violate federal and state clean air standards," according to Merritt.

Mick Rusch is marketing director for Madison Metro Bus Service, which has agreed to encourage ride-sharing by offering free rides on Clean Air Action Days.

"Get on the bus today, our meters are bagged, we're not accepting any cash," he says.

Mick also says Metro will lose thousands of dollars in providing all those free rides today, but, he explains, he considers Clean Air Action Day an investment, both for Metro, as well as our environment.

"People going to and from work can realize how easy it is, I mean, you ride once for free but it's more the long-term thing is to show people how easy it is and maybe get people to ride on a more long-term basis," Rusch says.

Merritt says meteorologists at the state's Department of Natural Resources have already determined tomorrow will not be designated as a Clean Air Action Day.