Another air quality advisory was issued today by the Pima County Department of Environmental Quality because of the elevated levels of smoke and ground-level ozone.

Smoke from New Mexico wildfires, the heat and calm winds are causing high levels of air pollution in the form of particulates and ozone.

Particulate matter is made up of the specks of soot, dust and aerosols in the air. Ground-level ozone is formed when emissions from many sources, including vehicles, combine in the presence of intense sunlight and heat.

Individuals who are especially sensitive to air pollution may experience shortness of breath, coughing, throat irritation, wheezing and breathing discomfort. Sensitive people should reduce their exertion levels while outside.

It is possible that ozone and smoke levels may be elevated Saturday, the department said.