Clean air activists have screamed for tougher pollution rules not just in Merced County, but the entire San Joaquin Valley.
And on Thursday, they weren't satisfied. The California Air Resources Board approved the San Joaquin Valley Air District's plan to clean up fine particle pollution by 2014 -- a plan that isn't stringent enough, said Melissa Kelly-Ortega, program associate for the Merced/Mariposa Asthma Coalition.
"We're here to remind you people are dying -- you know that all too well," she said to board in Fresno before it made its decision.
PM-2.5, or fine particle pollution, can penetrate deep into the lungs to aggravate asthma, contribute to heart disease and cause premature death.
Mary-Michal Rawling, program manager of the Asthma Coalition, reminded the board that two people in Merced County died this year from asthma-related illnesses.
And according to the county's first "Asthma Report Card" -- released May 6 on World Asthma Day -- about 745 county children visit the emergency room because of asthma-related illnesses every year.
Although the state air board approved the plan, stating it "met all legal and technical requirements under the federal Clean Air Act," it directed the air district to add back-up measures strengthening regulations on fireplaces, boilers and industrial engines.
"I don't think this was sufficient," Rawling said, adding that the contingency measures were ones the air district was going to add anyway. "It doesn't give us any added benefit. It didn't take into account what the scientists are saying."
She was referring to an announcement made by the state air resources board about a recently-released public health study. The two-year study showed that fine-particle pollution is 70 percent more lethal than scientists had suspected.
State officials said the airborne soot prematurely kills up to 3,000 valley residents each year, nearly triple the previous estimates.
This information was presented Thursday at the Fresno board meeting, and activists said it should be proof enough to delay the air district's plan.
Advances in medical research have allowed scientists to better gauge the health effects of pollution, the new study shows. The air resources board in the study revised the statewide PM-2.5 mortality estimate from 8,200 annually to 24,000.
Bart Croes, chief of the state air agency's research division, said the study could probably be used to help push for lower PM-2.5 health thresholds. The federal level is 15 micrograms per cubic meter.
While some scientists believe people would be safer at half that level, more research is needed to establish this."We really don't know what the health-protection level is," Croes said.
This comes after other studies confirming Merced County's pollution problems. The county recently received failing grades by the American Lung Association for ozone and short-term particle pollution.
Merced was one of seven metropolitan areas -- including New York City, Detroit and Chicago -- that landed on two of the three "worst" pollution lists.
PM-2.5 particles, which often hang in the valley fog during fall and winter, are so small that 30 of them could fit on the width of a human hair.
The minuscule particles can come from fires, vehicles and chemicals that combine in the air. They are considered more dangerous than ozone or smog.
Most of this pollution is created in the valley when chemicals combine in the air. Oxides of nitrogen from vehicles combine with plumes of ammonia coming mostly from dairies to form a chemical speck called ammonium nitrate, which accounts for nearly half of the region's PM-2.5.
Based on old estimates, a researcher at California State University, Fullerton, said the valley's annual health-related costs for PM2.5 exceed $3 billion. Much of these costs were associated with the economic effect of losing so many people.
"Looking around at all the dust in the sky and the valley today -- it's a little depressing," Michal-Rawling said. "We have a lot of work to do and we don't have a plan that's strong enough to do it."
Reporter Dhyana Levey can be reached at (209)385-2472 or firstname.lastname@example.org.