Earth Log

Particles fill foggy Valley air, making breathing dangerous

Air monitors in the San Joaquin Valley show a spike in dangerous particle pollution — including Hanford readings three times the federal health threshold.

Monitors in Clovis, Fresno, Visalia, Porterville and Bakersfield are recording levels near twice the health standard for the pollution, called PM-2.5. The microscopic debris contains chemicals, soot, moisture and bits of dust.

The San Joaquin Valley Air Pollution Control District on Friday announced continuing restrictions on wood-burning in fireplaces throughout the Valley. No one is allowed to burn wood except in a federally certified stove, insert or other similar device that has been registered with the air district.

Children, senior citizens and people with lung problems should avoid the outdoors while the readings are spiking. The air district posts hourly updates on its website.

The debris is trapped in the Valley’s bowl. No storms have passed through the region since December, so there has not been enough air movement to clear out the pollution. But storm systems were supposed to pass through the southern part of the Valley late Friday, air officials said.

There have been exceedances of the PM-2.5 standard daily in the Valley since New Year’s Day.

Health scientists say PM-2.5 is dangerous because the small specks can evade the body’s natural defenses, lodging in the lungs and passing into the blood stream. PM-2.5 can trigger lung and heart problems. It also is blamed for about 800 premature deaths annually in the Valley.