FRESNO – There's a new annual price tag for breathing dirty air in the San Joaquin Valley: $6.3 billion, mostly because more than 800 people die years earlier than they should.

That's more fatalities due to bad air than car accidents, said nationally known economist Jane V. Hall, who Wednesday released her latest analysis of poor air quality in this region.

The dollar and death figures are nearly twice as high as Hall found in her first study two years ago, partly because stricter federal standards are in force. The new standards assume more people are harmed by bad air.

But she also said new research indicates microscopic specks of soot and chemicals are more dangerous than previously thought.

"There is a clearer consensus that lives are being shortened," she said.

The study, funded with a $90,000 grant from the William and Flora Hewlett Foundation, is intended to jolt residents, regulators and political leaders.

Hall, a California State University, Fullerton, scientist, worked with researchers Victor Brajer and Frederick W. Lurmann on the study, which also covered the South Coast Air Basin.

The study points out the continuing need to battle air pollution, said Seyed Sadredin, executive director of the San Joaquin Valley Air Pollution Control District. But he also said people still should understand air quality has improved.

"Things are not getting worse. These bigger numbers are the result of a new standard," said Sadredin. "But this study does give the valley good justification to advocate for more support in fighting air pollution."

The premature deaths and mounting costs are unacceptable, said Liza Bolaños, coordinator for the Central Valley Air Quality Coalition, a nonprofit group representing public health and environmental organizations.

"We have the capacity to clean this up," she said. "This is a wake-up call."

Hall and the other researchers said more than half the state's residents – 20 million people in the valley and South Coast – are exposed regularly to unhealthy levels of ozone and particle pollution.

The researchers combined the cost of breathing dirty air in both basins, arriving at a total of $28 billion. Health care costs and time lost at work are included in the total, but more than 80 percent of the cost is related to the value of the estimated 3,800 lives lost prematurely each year.

Microscopic specks called PM-2.5, which are more prevalent in colder weather, are the biggest worry. Most of the region's $6.3 billion cost is the value of people who die prematurely from exposure to PM-2.5.

Fresno last year had 75 bad days for PM-2.5, Bakersfield had 68 and Visalia 64. In the north valley, Modesto had 39 bad days. This region is considered one of the worst in the state for such pollution.

"In the San Joaquin Valley, 100 percent of the residents are exposed to fine-particle pollution at some time during the year," said Hall.

The PM-2.5 comes from many sources, such as diesel engines and fireplaces. But it also forms in the moist winter air when ammonia from dairy waste combines with vehicle exhaust.

Fresno County residents suffer the valley's biggest effects, with the loss of 212 people each year, valued at $1.4 billion, according to the report. The county also has the valley's highest yearly total of non-fatal heart attacks related to air quality – 156. PM-2.5 pollution has been linked to heart disease.

Hall and Brajer said the valley's 823 annual air-related deaths occur about 14 years sooner than they should.

The cost of each premature death is set about $6.7 million, a figure based on mainstream economic and federal studies of social value. Such figures have been used in economic analysis of social problems for decades, researchers said.

"We're not trying to value a single person," said Brajer. "This is a social value on reducing the risk of early death."