Ozone Air Quality Alert

05.30.13 | Abby Lutcher

The code orange alert is in effect Thursday for the Pittsburgh, Philadelphia, Berks County and the Lehigh Valley, and the Susquehanna Valley, the DEP said. Under the system, green represents good air quality, yellow is moderate, orange represents unhealthy pollution levels for sensitive people, and red warns of unhealthy pollution levels for everyone. Ground-level ozone, a key component of smog, forms during warm weather when pollution from vehicles, industry, households and power plants heats up, making it hard for some people to breathe. The elderly and those with respiratory problems such as asthma are especially vulnerable to air pollution and should limit outdoor activities, the DEP said.