As schoolchildren played on the blacktop, calling out to each other over the hum of the nearby freeway, Tyree Harris and his mother climbed aboard a big, white Winnebago.

His doctor's office had arrived.

Like every other young patient treated on the Breathmobile, an asthma clinic on wheels, Tyree, 13, receives respiratory exams, medication, equipment and periodic checkups that help control his asthma, all for free. His experience illustrates that asthmatic kids can breathe more easily -- if they are fortunate enough to have access to the right treatment.

"It's helping me learn about my asthma and just how important it is to take my medication," said Tyree, who goes to Bancroft Middle School in San Leandro, a mile south of the Oakland border.

Daniela Gonzalez, 6, of San Leandro, Calif., practices using her spacer and inhaler to treat her asthma on the Breath Mobile Thursday, Sept. 20, 2012 at
Daniela Gonzalez, 6, of San Leandro, Calif., practices using her spacer and inhaler to treat her asthma on the Breath Mobile Thursday, Sept. 20, 2012 at Woodrow Wilson Elementary School in San Leandro. (Alison Yin/For Bay Area News Group) ( Alison Yin )

"I don't want to go to the emergency room," he said. "I don't want to go through that moment again."

Children who live and play near the Bay Area's notoriously jammed freeways, ports or refineries, or in substandard housing, are rushed to the hospital for asthma treatment at alarming rates. Bay Area kids were hospitalized for asthma nearly 1,800 times in 2010 -- at a statewide average cost of $19,000 apiece. That's in addition to the 8,500 trips to the emergency room they made that year.

Oakland children are four times as likely as other California kids to have symptoms so severe they must be admitted to the hospital.

The Breathmobile and other interventions are fighting to change that unsettling reality. The West Oakland Environmental Indicators Project works to clean up the air children breathe. The Oakland school district has turned its attention to indoor air quality. Alameda County's Asthma Start program and the asthma clinic at Children's Hospital Oakland teach families how to treat a poorly understood disease.

When a child's asthma is not being treated properly, a flare-up could happen at any time, pulling him out of school and his parents out of work. The risks are even greater for those who are frequently exposed to things that irritate their lungs, such as air pollution, dust mites, mold and smoke.

Children with out-of-control asthma often rely too heavily on quick-acting "rescue" inhalers, such as Albuterol, while skipping a daily -- and more expensive -- "control" treatment that helps to prevent attacks from happening in the first place, doctors say. Physicians typically prescribe both kinds of medication for children with moderate to severe asthma.

The Breathmobile is a mobile asthma and allergy clinic that visits schools, such as Woodrow Wilson Elementary in San Leandro, Calif.
The Breathmobile is a mobile asthma and allergy clinic that visits schools, such as Woodrow Wilson Elementary in San Leandro, Calif. (Alison Yin, for the Bay Area News Group)

"I see it all the time," said Dr. Michael Lenoir, a Bay Area allergist and pediatrician who serves on the National Medical Association's Allergy & Asthma Initiative, about Albuterol. "It's cheap, and it's quick."

Research bears out Lenoir's experience. A 2007 survey by the California Department of Public Health found that 28 percent of children with frequent asthma symptoms did not take preventive medication, and that only 38 percent had an asthma management plan from a doctor. When USC and University of Minnesota researchers analyzed the insurance claims of nearly 9,000 pediatric asthma patients, they discovered prescriptions for preventive medication were filled only about 40 percent of the year, on average.

The medical providers aboard the Breathmobile not only stress how crucial it is for patients to take their medicine as the doctor has ordered, but they also give it to them for free.

Tyree's mother, Lydia, said she had lost her health insurance the year before. She'd panicked, wondering how she'd be able to keep her athletic son healthy and safe.

"This is like a blessing," she said, as Tyree had his checkup. "It gives me peace of mind."

Since the bus began making the rounds at Bay Area schools in fall 2009, the program has treated about 330 patients in Northern California. Staffed with a doctor or nurse practitioner, a respiratory therapist, a nurse and a bilingual driver, it regularly stops at schools in Oakland, Berkeley, West Contra Costa County, San Leandro, Emeryville and Bayview-Hunters Point. The model was developed at USC and is locally operated by the Prescott-Joseph Center for Community Enhancement in West Oakland.

Tyree Wilson, 12, of San Leandro, Calif., practices using his spacer and inhaler to treat his asthma on the Breath Mobile Thursday, Sept. 20, 2012 at
Tyree Wilson, 12, of San Leandro, Calif., practices using his spacer and inhaler to treat his asthma on the Breath Mobile Thursday, Sept. 20, 2012 at Woodrow Wilson Elementary School in San Leandro. (Alison Yin, for the Bay Area News Group)

The Breathmobile costs about $500,000 a year to run, said Dr. Washington Burns, the center's director. He estimates that the program saves as much or more in health care costs -- dozens of hospitalizations and hundreds of emergency room visits that his patients no longer need.

Still, Burns has to hustle for the program's survival. He has kept the Breathmobile alive through a collection of grants, but he has yet to find a more stable funding source. A promising asthma outreach program in Contra Costa County's public health department ended after a major grant expired in 2010.

"I don't want this program to go away," Burns said. "A program like this should not end. It's doing so much good."

Staff writer Katy Murphy and photographer Alison Yin produced this project while participating in The California Endowment Health Journalism Fellowships, a program of the University of Southern California's Annenberg School of Journalism.