The ARB acknowledged: "The bad economy has both improved the state's air quality and made anti-pollution upgrades unaffordable."

The board also had other considerations behind its regression from the diesel emission rules that were alleged to be able to prevent 9,400 premature deaths if implemented.

The ARB questioned the death figure and ordered state researchers to redo the report that had concluded that 3,500 people prematurely die each year due to diesel emission-caused pollution.

The order was made Wednesday after a hearing on concerns over the cost of retrofitting and replacing and after the finding of a report compiler who had lied about his academic credentials.

Christina Ramorino, who works for her family's Roadstar Trucking Company in Hayward, said past emission rules had cut the company's driving force already by 19 percent in the past two years.

"I'm 26 years old, starting my career, and concerned these regulations could very well put us out of business," Ramorino said at the ARB hearing.

Her father Robert said the company could afford to comply with the new standards only if it cut all medical and dental benefits for its employees.

But environmental activists and public health advocates pushed to keep the regulations.

Bonnie Holmes-Gen, senior policy director for the American Lung Association of California, quoted at the same hearing an asthma patient as saying: "There are retrofit devices for trucks, but not for my lungs."

Public health advocates stressed that California, a state plagued by smoggy skies and rising asthma rates, just cannot afford to be lenient on pollution standards.

The new rules would otherwise be expected to help reduce ozone-eating nitrogen oxides and soot-forming carbon particulates that can become embedded in human lungs.

"We're very aware of the economic problem. We're also very concerned about the hardship of those suffering daily from lung-health problems. We believe those voices need to be heard," said Holmes-Gen.

Almost all the 50 US states have to write their clean air "state implementation plans" (SIP) to show how they will meet the tighter federal standards.

For the time being, 19 states are having air pollution problems similar to those found in California.

And any state that fails to develop an "approvable" SIP can be subject to numerous federal sanctions including emission caps limiting economic development and losses of federal highway transportation funds.

(Xinhua News Agency December 11, 2009)