Buy Photo

Henry A. Barrios / The Californian

In this mid-January photo, children play outdoors at Franklin School during the noon recess. Many schools in Kern County raise a colored flag each day to inform parents, students and staff about the air quality expected for the day.

If you thought a "red alert" was bad, try purple.

Each day, scores of schools in Kern County hoist a color-coded flag to let parents, students and staff know what kind of air quality to expect that day.

A green flag predicts good air quality, yellow signals moderate, orange indicates the air is unhealthy for sensitive groups and a red flag -- well, that's bad news for pretty much anyone who breathes.

Air officials say the San Joaquin Valley is experiencing its worst winter air pollution on record, and last weekdozens of schools in Bakersfield went to an air alert level for which they have no flag at all.

"I was stunned," saidDebbie Wood, health coordinator for the Bakersfield City School District, which has used the flag program for about a decade.

But early last week, concentrations of microscopic soot particles -- known as PM-2.5s -- spiked well above 75 micrograms per cubic meter of air. At one point on Jan. 6, levels climbed higher than 100.

Wood, a registered nurse who has worked on school air quality and asthma-related issues for more than 16 years, decided to go to Level 5: the color purple.

She had never called a "purple alert" before.

After Wood instructed schools to go to purple alert, red flags remained on school flag poles because purple flags don't exist. They have simply not been needed at school sites.

Until now.

"It's really sad to think that our air quality is that bad," said Bakersfield native Joyce Calvillo, who was at Downtown Elementary School on Monday afternoon to pick up her grandchildren, Ava and Jackson Christenson.

What Level 5 meant for teachers and the Bakersfield City School District's 29,000 students was a ban on all outdoor activity, except the most basic movement between classrooms, cafeterias, restrooms and school buses. P.E. classes could not be held outdoors, and students and teachers were essentially cooped up in classrooms all day.

"It's hard on the teachers," said Downtown parent Fletcher Perez.

But one of Perez's school-age children suffers from asthma, and Perez said she's glad the district keeps a close eye on air quality and adjusts student activities accordingly.

"Asthma is so prominent in the valley," she said. "I support the flag program and the limitations on exercise -- because I've seen the effects."

According to Wood, the flag program and the accompanying changes to student activities have significantly reduced absenteeism due to asthma and other respiratory illnesses. And ambulance calls to schools for those illnesses have been cut to near zero.

But there's a flipside.

In Kern County, where childhood obesity, diabetes and other illnesses linked to sedentary lifestyles are rampant, it's frustrating to have to limit children's physical activity due to factors beyond schools' control.

Seyed Sadredin, executive director of the San Joaquin Valley Air Pollution Control District, said the district developed the flag program more than 15 years ago. Recommendations regarding students' outdoor physical activity were added more recently.

"We now provide schools with hour-by-hour readings," Sadredin said. "It lets students, parents and coaches ... make adjustments as air quality gets better or worse."

On red-flag days students may walk the track, but vigorous outdoor activities such as running, playing basketball or jumping rope are off-limits.

Larger schools with a gymnasium or other indoor P.E. space have more options than smaller campuses like Downtown on bad-air days. But Wood said when students are limited in their physical activities, teachers are encouraged to let students take a few minutes to dance, maybe pop a beach ball around the classroom or simply stand and walk in place.

It helps them learn, she said.

In the meantime, until the weather breaks, until the valley's high-pressure "bubble" is pushed out by active winds and rains, valley residents have more bad air to look forward to.

But on Monday, the flag flying at Downtown Elementary School was a bright yellow. Not perfect, but certainly an improvement.