The California Air Resources Board Dec. 12 approved two diesel truck regulations that will dramatically cut the largest source of diesel pollution in the state and are the first of their kind in the United States, according to Environmental Defense Fund (EDF). The Air Resource Board estimates that the truck regulations are expected to save 9,400 lives between 2010 and 2025 and greatly reduce health care costs.

Retrofitting these trucks with particulate matter filters can reduce diesel soot up to 85 percent, and upgrading to newer trucks to meet EPA's latest engine standards can reduce smog-forming nitrogen oxide up to about 90 percent. The state is offering truckers more than $1 billion in funding to offset the costs of complying with the new rules.

Diesel trucks are the largest emitter of toxic diesel particulate matter in the state due to a combination of lagging emission standards, the long life of the diesel engine, and the high number of miles each truck travels. The newest diesel trucks are much cleaner than their predecessors thanks to recent EPA regulations, but the natural turnover of trucks will not happen fast enough in order for the state to meet federal clean air requirements and to achieve near and long term health benefits. There are more than 900,000 diesel trucks in California, but they produce more than double the amount of the particulate matter and nitrogen oxide from all of the state's 20 million passenger cars and trucks.