Authorities have called an Air Alert from Monday through Wednesday, saying valley residents need to be aware of rising ozone levels with school beginning and traffic expected to increase as a result.
The San Joaquin Valley Air Pollution Control District announced the alert on Friday. It's hoped that motorists will avoid idling their cars and using drive-through services when an alert is declared. Residents are also encouraged to car-pool.
School is scheduled to begin Monday and Tuesday in most of Merced County's school districts. More vehicles are expected on the roadways as parents with children and older students head back to school.
In addition to reducing their driving during Air Alerts, residents are asked to shift ozone-creating activities such as mowing and edging lawns with gasoline-powered equipment to early mornings.
Ozone forms best in hot, sunny, stagnant conditions. Air quality was better early in August after the July heat wave broke and temperatures dropped into the 90s for several days. But the possibility of 100-degree days and ozone problems have returned.
"In the past couple of years, we have had an extraordinary level of cooperation by the public," said Seyed Sadredin, district executive director.
Ozone is a corrosive gas that damages the lungs, eyes and skin. Health experts say ozone can trigger lung and heart ailments and cause early mortality.
The cooperation could help the valley achieve the one-hour federal ozone standard that has proved elusive for many years. Through vehicle registration fees, motorists are paying most of a $29 million annual penalty for missing the cleanup deadline on the standard.
The one-hour federal ozone standard was abolished in 2005, but air districts still must achieve the defunct threshold or face penalties. The valley's air regularly exceeds the more stringent eight-hour federal ozone standard, which has cleanup deadlines in the next decade.