HARRISBURG – The PA Department of Environmental Protection has expanded the Code Red Air Quality Alert to cover all of central PA now through 8 a.m.Thursday. Poor air quality may linger through the day Thursday as light wind and limited vertical mixing of the smoke from Canadian wildfires occurs. A Code Red Air Quality Alert means that air pollution concentrations may be unhealthy for some members of the general public. Members of sensitive groups may experience more serious health effects. Sensitive groups include people with heart or lung disease, older adults, children and teenagers, and outdoor workers. The effects of air pollution can be minimized by avoiding or reducing long or intense outdoor activities.