The Pennsylvania Department of Environmental Protection announced a Code Orange Air Quality Action Day for ozone in Butler County, among others for Monday, July 29.

On a Code Orange Air Quality Action Day, young children, the elderly and those with respiratory problems, such as asthma, emphysema and bronchitis, are most vulnerable to the effects of air pollution and should limit outdoor activities.

Most common during the summer months, ozone is formed when airborne chemicals such as nitrogen oxides and volatile organic compounds called precursors react with sunlight.

Residents can reduce ozone pollution by driving less, carpooling, setting air conditioning units to a higher temperature and turning off lights that are not in use.

Other counties in the region with a declared Action Day include Allegheny, Armstrong, Beaver, Butler, Fayette, Washington and Westmoreland.