A strong high-pressure system off the coast of California is limiting air flow and dispersion throughout the San Joaquin Valley, prompting the SJ Air Pollution Control District to issue a Health Cautionary Statement.
“Unfortunately, these stagnant conditions may cause high concentrations of particulate pollution in our region,” said Jon Klassen, District Air Quality Analysis Manager. "While these conditions bring about pleasant unseasonably warm temperatures, it is best to avoid heavy outdoor activities during periods of elevated particulate matter concentrations,” added Klassen.
The District is issuing a Health Cautionary Statement effective Wednesday until conditions improve and is encouraging Valley residents to use the District’s state-of-the-art Real-time Air Advisory Network (RAAN) on the District’s website at www.valleyair.org/RAAN that provides all residents with real-time air quality information for neighborhoods throughout the Valley.
Although the federal ambient air quality standard for particulate matter set at 35 µg/m3 is based on the average exposure to such concentrations over a 24-hour period, the District urges the public to utilize RAAN as a more health-protective option. The District RAAN system communicates actual hourly concentrations and issues warnings during elevated hourly concentrations even when daily average concentrations may be below the health standard established by EPA.
At noon Thursday, there was a moderate amount of fine particulate matter in the Turlock area and the Air District was advising sensitive individuals to reduce prolonged and/or vigorous outdoor activities.
After decades of investment and sacrifice by Valley businesses and residents, emissions have been reduced by more than 80 percent and are at historically low levels. However, these stagnant conditions that the Valley is facing due to extraordinary weather conditions can still lead to elevated particulate matter concentrations. Particulate pollution is harmful and has been correlated with asthma attacks, bronchial infections, heart attacks and stroke.