Jesse and Jessika Hernandez were barely a year old when the twins contracted asthma.
Now, at age 10, they grapple with the illness every day, missing school and ending up in a hospital, because of the poor air quality in their native Fresno.
The two were among several dozen that attended the U.S. Environmental Protection Agency's Sacramento hearing on national air quality standards Thursday. The agency is proposing a change to the annual standard for soot and is seeking the public's input.
"We're here today to listen," EPA spokeswoman Alison Davis said.
At the hearing, regulators got an earful. Some decried the agency for not protecting public health, while others blamed regulations for driving them out of business.
"It's a difficult balancing act," said Errol Villegas, program manager for the San Joaquin Valley Air Pollution Control District. "How do we balance public health with jobs?"
The San Joaquin Valley is among the worst-polluted areas in the nation.
Current EPA rules for soot allow 15 micrograms per cubic meter, but the agency is now proposing 12 or 13 micrograms. Environmentalists have said that's not enough – they want 11 instead.
The stakes for California are high. It is one of the worst soot-polluted states in the country.
The American Lung Association said 70 percent of California's soot pollution originates in the transportation industry, with trucks, trains and airplanes the biggest polluters. The remaining 30 percent comes from power plants, manufacturing and home sources.
Robert McClernon, a former trucker, said the current regulations "destroyed" his livelihood. In 2009, McClernon said he was forced to close his trucking business, because his equipment didn't meet EPA rules.
But Tony Wexler, director of the Air Quality Research Center at UC Davis, believes the financial cost of clean air is justified.
"It's cheaper to have stricter regulations, because health costs are much higher," Wexler said. "Industry groups only see the costs in front of them."
Environmentalist and clean air groups were out in full force at the hearing, with a slew of representatives testifying before the five-member panel. Only a handful of speakers, mostly from business groups, argued for maintaining the current standard. The Sierra Club led a small rally at Cesar Chavez Plaza across from the California EPA building, where the hearing was held.