Code Orange Air Quality Day Thursday In 5-County Philly Region: PA DEP

PHILADELPHIA — The five-county Philadelphia area will have a Code Orange Air Quality Action Day for ozone levels Thursday.

The Pennsylvania Department of Environmental Protection has declared the day for ozone for Bucks, Chester, Delaware, Montgomery, and Philadelphia counties.

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

Partly to mostly sunny skies and temperatures in the mid 90s will likely contribute to 8-hour average concentrations of ozone in the Code Orange range on Thursday.

An Air Quality Action Day is declared when the Air Quality Index is forecasted to be Code Orange or higher.

Residents can do to AirNow.gov to check current air quality conditions in their area.

Ozone is formed when airborne chemicals such as nitrogen oxides and volatile organic compounds — called "precursors" — react with sunlight.

High ozone levels are most common during summer months, when there are long days with plentiful sunshine and high levels of ozone precursors combine.

Although ozone precursors are most often generated by car exhaust and industrial air emissions, wildfire smoke can provide additional precursors.

Ozone pollution is most common in densely populated areas with higher amounts of car exhaust and industrial air emissions.

Residents and businesses in the five-county region are strongly encouraged to voluntarily help reduce ozone air pollution by:

• driving less by carpooling or using public transportation;
• combining errands to reduce vehicle trips;
• limiting engine idling;
• refueling cars and trucks after dusk; and
• conserving electricity by setting air conditioning to a higher temperature and turning off lights that are not in use.