Smoke from California wildfires taint the view

Pima County, Ariz. (September 8, 2020) – A change in the weather is, again, allowing smoke from multiple wildfires in California to come into the Tucson area. So far, the smoke is high enough in the air to avoid being recorded at Pima County Department of Environmental Quality’s (PDEQ) monitoring locations, but if forecasted winds increase, that could change.

“At this point, air quality is in the ‘good’ range because the smoke is staying elevated, but as the wind picks up, a mixing of the air may happen and increase the number of smoke particles at nose (and monitor) level,” said Beth Gorman, PDEQ Senior Program Manager. “If that happens and you smell smoke where you live, we encourage those who are very sensitive to air pollution to stay inside or reduce excursion when outside.”

Wildfire smoke can cause another air pollutant, ground-level ozone, to increase, in addition to particulate matter. Burning trees increases the amount of two ingredients the form ozone (volatile organic compounds and oxides of nitrogen) and, under the right weather conditions, ozone levels will rise. This happened recently in Pima County when local fires and those from other states caused multiple exceedances of the EPA health standard. Ozone thrives in calm, stagnant conditions, so the winds that are occurring now may help reduce the accumulation of ozone in the air.

Smoke and hazy skies could remain in the area until Friday. Up-to-the-hour air pollution levels for eastern Pima County are available here (http://envista.pima.gov/aqidynamicsummary.aspx ). Information on wildfire smoke and air quality is available here (https://webcms.pima.gov/cms/One.aspx?portalId=169&pageId=450398 ).