So yet another study, this one by MDs at Harvard Medical Center, shows the devastating health effects of long-term exposure to on-the-job diesel exhaust. The Harvard team's findings show professional truck drivers are 50% more likely to die of heart disease than the general population.

This on the heels of an NRDC study showing port truck drivers are exposed to dramatically elevated levels of cancer-causing black carbon, which prompted the Oakland Tribune to suggest that port drivers' pursuit of a livelihood may be in fact killing them.

And here's the real kicker, the overwhelming majority of port drivers are so-called independent contractors, a scheme that allows the trucking companies that hire them to skirt their responsibilities as employers, i.e., worker's comp and health care. Most of the 16,800 LA and Long Beach port drivers are choking on their own exhaust with no means to seek medical care, let alone pay for routine maintenance.

Even Brian Griley, president of Southern Counties Express noted in a presentation sponsored by the Port of Long Beach, "Drivers take on all the risks - accidents, repairs, productivity and sickness."

That's a tall order, considering another trucking company exec bluntly told the Wall Street Journal:

"They can haul dirt for more money than cargo."

Could be. But the point here is not what they're hauling for dirt cheap wages, it's that they're breathing in toxic fumes that make them, their children, and area residents sick. The public shells out millions each year to treat uninsured drivers and harbor community residents continue to pay for diesel pollution with their lives - two each week the Ports fail to take comprehensive action.

As economist John Husing noted, the Clean Trucks Program "will yield a cumulative economic benefit of $4.7 to $5.9 billion due to reductions in premature deaths, lost work time and medical problems." An impressive figure, but how do you put a price tag on someone's life?