State could get tough on dirty diesels

But that was before Mira Loma became one of Southern California's "diesel death zones," as activists call the truck-choked freeways and distribution hubs that fan out from the massive ports of Los Angeles and Long Beach.

Today, a blanket of smog and dust smothers Mira Loma's grimy subdivisions. "You think the warehouses will bring work and money," said Vielmas, 44, who became a community organizer after her two grandsons developed asthma, which she blames on diesel pollution. "The cost of industrialization -- we are paying for it with our health."

This week, a decades-long struggle between California regulators and the national trucking industry will come to a head in Sacramento when the Air Resources Board votes on whether to require owners to fit about 230,000 heavy-duty trucks with diesel exhaust traps and replace about 350,000 older, dirty engines over the next 15 years.

Big-rig crackdown

The crackdown is unprecedented: No other state requires existing trucks to be retrofitted or retired. And it raises thorny interstate commerce issues: Any big rig that travels through California, no matter where it is registered, would be affected.

At a cost of $5.5 billion, the diesel rule, which covers trucks and buses, would be the most expensive air pollution regulation ever adopted in California.

Regulators say, however, that the cost of failing to act would be far higher. Heavy-duty rigs are responsible for a third of all the smog in California. State officials project that the new rule would save 9,400 lives between 2010, when it takes effect, and 2025. With tens of thousands of hospital admissions linked to air pollution, Californians would save up to $68 billion in healthcare costs in the first 15 years, according to economists for the air board.

Last week, 17 national and state health groups, including the American Heart Assn., the American Cancer Society and the California Medical Assn., called for passage of the rule, noting that half of all Californians live within a mile of a freeway.

"These pollutants are taking a serious toll on California's public health," they wrote to the air board, adding that diesel exhaust can cause respiratory and cardiovascular disease, cancer and premature death.