Cold, snow-covered surfaces combined with a forecasted high pressure weather system could cause breathing problems for certain midstate residents on Friday.

State environmental officials have called for a code orange air quality action day for south-central Pennsylvania counties, which means unhealthy pollution levels may impact people who are sensitive to air pollution, according to the Pennsylvania Department of Environmental Protection.

The code has been issued for Cumberland, Dauphin, Lancaster, Lebanon and York counties, among others.

In most cases, the lessened air quality targets young children, the elderly and people who suffer from respiratory problems, officials said.

To combat the issue, vulnerable midstate residents should limit outdoor activities.

The code is in line with the U.S. Environmental Protection Agency’s air quality index, which standardizes quality by assigning colors to daily air conditions. According to the index, green signifies good air quality, yellow represents moderate air quality, orange stands for unhealthy pollution levels for sensitive people and red warns of unhealthy pollution levels for the general public.

via Code orange issued for midstate air quality Friday, could cause breathing problems | PennLive.com.