Smoke from the South Fork Fire and Empire Fire, both burning in Mariposa County, and emissions from the recent Flat Fire and Hill Fire in Fresno County are affecting air quality in locations throughout the San Joaquin Valley. Triple-digit temperatures coupled with stagnant air are conducive for the formation of ozone. Elevated particulate matter and ozone levels throughout the Valley are prompting Air District officials to issue a health cautionary statement Valley-wide.

Air officials announced on Monday that they are expecting these poor air quality conditions to continue through this week, based on the projected weather conditions, and impacts from these wildfires will continue to be a concern until the fires are extinguished.

The wildfires burning around the Valley coupled with high heat and a strong high pressure system lingering over the Valley are causing smoke emissions to remain trapped within the air basin and spikes in particulate matter levels and ozone levels are possible, particularly during the afternoon hours.

“The businesses and residents of the Valley have done so much to reduce summertime pollution that it is unfortunate when these wildfires overwhelm that great work,” stated Seyed Sadredin, the District’s Executive Director/Air Pollution Control Officer. “However, the public needs to be advised that while these fires burn and bring smoke into the Valley, they need to take the appropriate steps to protect their health.”

Smoke from wildfires produces particulate matter (PM) and contributes to the creation of ozone, which can cause serious health problems including lung disease, asthma attacks and increased risk of heart attacks and stroke. People with existing respiratory conditions, young children and elderly people are especially susceptible to health effects from these pollutants. Air District officials urge residents to follow their doctors’ orders when exposed to wildfire emissions and stay indoors if at all possible.

Also, a reminder that the District’s Real-time Air Advisory Network (RAAN) monitors are designed to detect the fine particulates (called PM 2.5 which are microscopic in size and not visible to the human eye) that exist in wildfire smoke. Ash particles are much larger in size and will not be detected by the Air District’s monitors. Therefore an area may be experiencing impacts from these wildfires while the PM monitor reflects a moderate reading. If you can see or smell smoke or ash, that is an indication that you should be treating air quality conditions as “Unhealthy” and remain indoors.

Residents can check the District’s wildfire page at www.valleyair.org/wildfires for information about any current wildfires and whether they are impacting the Valley. Residents can also check the nearest air monitor to their location to determine localized air-quality conditions. Visit the Real-time Air Advisory Network to subscribe for free: www.valleyair.org/RAAN.

For more information, visit www.valleyair.org or call the District office in Modesto at 209-557-6400.