The Air District officially lifted its first Air Alert of the season on Thursday; and the Valley is even closer to a historic achievement.

Despite high temperatures and ideal conditions for ozone formation, local air officials reported that no exceedances of the 1-hour ozone standard materialized throughout the air basin during the three-day alert, moving the Valley forward toward attainment of the elusive federal health standard.

“It is absolutely a testament to the public’s understanding of the importance of reducing emissions, and their action in doing so, that we are moving closer to this accomplishment,” said Seyed Sadredin, the Air District’s executive director and air pollution control officer. “We are not out of the woods yet, and conditions can change quickly. The next six weeks are critical for avoiding additional exceedances of this standard.”

During the Air Alert period, Aug. 19-21, temperatures soared in the Valley: 110 in Fresno, 108 in Bakersfield and 105 in Modesto. One-hour ozone exceedances typically happen in late August and September, as stagnant, hot weather becomes entrenched in the Valley and back-to-school traffic increases vehicle emissions, the No. 1 source of ozone-forming pollutants. In the past 10 years, the Valley has seen a dramatic decrease in 1-hour ozone violations; however, attainment for this health-based standard has remained just out of reach. In order for attainment to be reached, three consecutive years of acceptable monitoring data are required. Going into the first Air Alert of the season, the Valley has had two such years.

As the Valley moves into late August and September, the area typically experiences more atmospheric stagnation.  These conditions, combined with high temperatures, make the Valley more prone to trapped pollutants and ozone formation.  Because of this, Air District officials hope more Valley residents will take part in reducing air pollution.  Atmospheric conditions can change rapidly with little opportunity for advanced notice through District Air Alerts.    

“We hope that some of the air-friendly changes that people made during this first Air Alert will become everyday habits,” added Sadredin.

Air Alerts are called when conditions are forecast that are conducive to ozone formation. Ozone is a summertime pollutant that is formed in heat and sunlight. High ozone levels can exacerbate respiratory conditions such as asthma and cause long-term lung damage.

“As we move into typical late-summer, stagnant conditions, it is increasingly important to take those small steps, such as not idling your vehicle, to keep ozone levels down,” Sadredin said. “There’s a lot at stake.”

For more information, visit www.valleyair.org.