An air quality advisory is in effect from 1 p.m. Friday to 1 a.m. Saturday central and western New York, as well as the eastern Lake Ontario region, for potentially high ozone levels.

The state Department of Environmental Conservation and state Department of Health predict elevated levels of pollutants from vehicle exhaust, power plant emissions and chemical reactions in the atmosphere.

State officials said exposure to elevated levels of fine particulate matter can worsen medical conditions such as asthma and heart disease. People with heart or breathing problems, children and the elderly may be particularly sensitive.

Staying indoors may reduce exposure and strenuous outdoor activities should be avoided.

A toll-free air quality hot line -- (800) 535-1345 -- has been established by the DEC and more information on ozone and particulate matter is available on DEC's Web site at www.dec.ny.gov and the department of health Web site at www.health.state.ny.us.