PARLIER, Calif. – With crop dusters buzzing in the skies above, spray rigs stalking the fields and the occasional pesticide drift that hospitalizes scores of people, airborne chemicals are a fact of life in the little farm towns of the San Joaquin Valley. But no one knows what chemicals linger in the notoriously polluted air and whether long-term exposure could lead to increased rates of asthma, cancer or neurological problems. To find out, the state Department of Pesticide Regulation started a novel yearlong air monitoring program this month that will gauge levels of 40 airborne chemicals for the first time. While farmers are wary the results could spell stiffer regulations, doctors and school officials who deal with chronic respiratory diseases such as asthma said it’s about time someone found out what rural residents are breathing. The agency, with help from the state’s Air Resources Board, installed pumps that draw in air around three schools in town, gauging levels of chemicals such as methyl bromide that are either harmful to human health or contribute to air pollution. Parlier, a largely Hispanic town of about 12,000 about 20 miles southeast of Fresno, is the kind of place often overlooked by policymakers in the state capital – and that’s precisely why it was chosen, state officials said. “We want to ensure that our environmental laws provide a fair measure of protection for everyone who lives and works in our state,” said Mary-Ann Warmerdam, the department’s director. “We are particularly concerned about the health and welfare of children.” The economy here relies on farming, and in winter, when there’s nothing to plant or harvest, a third of adults don’t work, making it one of the state’s poorest towns. At Cesar Chavez Elementary School, one of the monitoring sites, even the second-graders are aware that the air they breathe can be harmful. Like other schools in the region, Cesar Chavez flies color-coded flags describing air quality. Kids are eager to avoid the red flag that means the air is so unhealthy they can’t play outside, he said. “They know the stuff that’s hurting them isn’t always natural, that sometimes it’s introduced by us,” said second-grade teacher Paul Martinez. With three or four children out of 20 with asthma in his class every year, Martinez has gotten used to going on field trips carting inhalers in case a child has an asthma attack. His class activities can include asking healthy students to breathe through straws to understand the difficulty classmates face that keep them from playing sports. Lesson plans can focus on Chavez, the labor leader after whom the school was named, who once staged a hunger strike to protest the harm pesticides caused farmworkers. Even farmers, still chafing from recent air quality rules meant to curb their contribution to the region’s dirty air, saw the need for more testing. “If we can find out if there are things we can do different, or better, it’s very important,” said Harold McClarty, whose family has grown peaches, plums, nectarines and citrus around Parlier for four generations. He has two children in local schools – one of them with asthma. “It’s our livelihood, but it’s also our land, and our families,” he said.160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MORESanta Anita opens winter meet Saturday with loaded card “It would be nice to have the data, and be able to correlate – is it the use of a pesticide? Is it dust, smog?” asked Dr. Rogelio Fernandez, who has seen the incidence of respiratory disease go up in his 15 years of working with farmworkers and their families. “If there’s something we can do to decrease these numbers, we need to move in that direction,” he said. “And the first step is to find out if there is something in the air.” The department has measured pesticides for shorter periods, but this $1 million project is part of a comprehensive push to make sure that chemicals needed to kill weeds, insects and fungi that threaten crops don’t harm the families that tend them, state officials said. Pesticides are only one of the components of the noxious soup of chemicals that makes this valley one the nation’s most polluted air basins. Car exhaust, soot from fireplaces, even gases rising from cow manure contribute a bigger share in the nation’s most productive farm region. No state or federal agency has spelled out how much of the chemicals are safe to breathe every day, but determining what is in the air is the first step in that direction.