Today is expected to be the first “unhealthy ozone” day in coastal areas for 2001, and the Department of Environmental Protection is advising people to use caution.

Those with respiratory disease or allergies should avoid strenuous activities like jogging in the middle of the day when ozone levels are expected to reach moderate levels, according to DEP. Such activities can cause shortness of breath, coughing, throat irritation and other symptoms in people who are susceptible.

“Sunny skies, hot temperatures, and southwesterly winds ahead of a weak cold front will push concentrations above the federal health-based air quality standard,” the DEP warned in an advisory issued Tuesday.

Last year there was just one unhealthy ozone day, according to Martha Webster, DEP meteorologist and back-up ozone forecaster.

Webster said that in recent years 1997 was a high-water mark with 10 such unhealthy days recorded in one or more of the DEP’s three regions monitored: northern, inland and coastal.

Records show there were seven unhealthy ozone days in 1998, eight in 1999 and just one last year.

“Last year didn’t set up well [with cool weather] for ozone transportation and production,” Webster said.

Ground ozone is created naturally by sunlight and chemical reactions. Ozone is also created when engines run, paints dry and cleaners are used.

To help reduce ozone concentrations in Maine, the DEP suggests that people should conserve electricity, reduce auto use through carpools, limit gas-powered lawn equipment use to after dusk and use environmentally friendly paints and cleaning products.

The DEP only makes forecasts a few days in advance based on expected conditions at monitoring sites. The coastal region forecasts are based upon conditions for Kittery, Kennebunk, Cape Elizabeth, Port Clyde and McFarland Hill on Mount Desert Island.

For more information, the DEP has an ozone hot line at (800) 223- 1196 and online information at http://janus.state.me.us/dep/air/ozone/ozone.htm