The Pima County Department of Environmental Quality has issued an air quality advisory for this weekend.
Officials said ground-level Ozone levels will be elevated for the next couple of day.
Anyone who is particularly sensitive to Ozone pollution should limit time spent outdoors until after 6 p.m. when Ozone levels begin to decrease.
Officials say the increase in pollution may cause shortness of breath, coughing, throat irritation, wheezing and breathing discomfort for those affected.
Causes of increased Ozone pollution are car exhaust, power plant emissions, gas vapors and smoke from wildfires.
For the latest air quality numbers go to http://www.pima.gov/deq