The wildfires that are surrounding the San Joaquin Valley, combined with an incoming high-pressure system, has prompted the local air district to issue another health warning for area residents.

The San Joaquin Valley Air Pollution Control District anticipates unhealthy air quality in the Valley through the coming days and warns residents to stay indoors to reduce their exposure to particulate matter emissions.

The Valley got a recent reprieve from the smoke and ash last week because of the winds, but the high-pressure system coming in and lack of winds will act like a lid over the Valley, pushing the particulate matter lower.

"We are seeing air conditions deteriorate," said the Air District's Director of Air Quality and Science Jon Klassen during a Zoom press conference Tuesday. "Air quality will probably get worse over the week. The pollution will have nowhere to go."

Klassen said the record number and size of wildfires this season has made for the worst air quality ever recorded in the Valley.

"This wildfire season has been one for the records," Klassen said. "We've not had this widespread of an air quality issue, high concentrations everywhere, Valley-wide for weeks and weeks and weeks."

The SQF Complex Fire in Tulare County and the Creek Fire in Fresno and Madera counties are sending smoke onto the San Joaquin Valley Floor causing PM concentrations to rise across the District and especially in foothill communities. In addition, the Glass Fire in Napa County is causing smoke to drift southeast into San Joaquin and Stanislaus counties. These impacts are expected to continue through next week with smoky conditions persisting until the fires are extinguished.

Particulate matter can trigger asthma attacks, aggravate chronic bronchitis, and increase the risk of heart attack and stroke. Individuals with heart or lung disease should follow their doctors’ advice for dealing with episodes of PM exposure. Those with existing respiratory conditions, including COVID-19, young children and the elderly, are especially susceptible to the health effects from this form of pollution.

Anyone experiencing poor air quality due to wildfire smoke should move indoors, to a filtered, air-conditioned environment with windows closed. The common cloth and paper masks individuals are wearing due to COVID-19 concerns may not protect them from wildfire smoke. The Air District also recommends air filters in homes and vehicles be replaced.

Residents can use the District’s Real-time Air Advisory Network to track air quality at any Valley location by visiting myRAAN.com. District air monitoring stations are designed to detect microscopic PM 2.5 particles that exist in smoke. However, larger particles, such as ash, may not be detected. If you smell smoke or see falling ash in your immediate vicinity, consider air quality “unhealthy” even if RAAN displays lower level of pollution.

The public can also check the District’s wildfire page at www.valleyair.org/wildfires for information about any current and recently past wildfires affecting the Valley. In addition, anyone can follow air quality conditions by downloading the free “Valley Air” app on their mobile device.