Diesel Truck Pollution: The Truth is Lost in the Fumes

Diane Bailey, Senior Scientist, San Francisco

A couple things about diesel truck pollution: there’s still a lot of it in California, truck drivers are suffering from it, and most truck owners oppose rolling back the statewide truck clean-up rule.  These facts have been obscured by all the fumes emanating from a tiny but vocal minority of trucktivists who want to do away with the Air Resources Board measure curbing diesel pollution from trucks.  ARB will consider allowing some additional delays to their statewide diesel truck and bus rule adopted six years ago.

The diesel truck rule was already delayed in 2010 in response to the recession, but it remains a pillar of public health, cutting toxic diesel soot from the state’s largest source by 80 percent.  When the rule is fully implemented, a total of 3,500 premature deaths will have been avoided, along with relief to thousands of families in high truck traffic areas, who are suffering from asthma rates that are twice as high as other areas.

While we’ve seen a lot of improvement in air quality over the past decade with many diesel clean-up regulations phasing in, thousands of polluting trucks remain on the road.  Diesel trucks are still the largest source of nitrogen oxide pollution in California, which contributes to smog and soot, and they emit more fine particulate soot directly than all of the cars on the road.  

The drivers of these trucks are on the front lines of exposure to diesel soot.  A 2007 NRDC study placing air monitors in the cabs of trucks, showed that drivers are exposed to increased diesel soot and health risks of roughly four times the average levels in urban areas.  While many drivers may feel fine in the short term, their lung and heart health is impacted in the long run, potentially leading to debilitating illnesses and shortening their lives.  (See this summary of the health impacts associated with diesel soot and fine particulate pollution)

We often talk about safeguarding the communities most impacted by diesel pollution. This remains a priority, but we need to recognize the drivers as part of those communities.   Cleaning up tailpipe emissions from trucks shouldn’t pit drivers against residents.  In fact, the vast majority of truck owners in California â€" at least 85 percent â€" are estimated to be in compliance with the truck rule. These owners have already made investments to clean up over 140,000 trucks and would be at an unfair disadvantage if the rule was weakened. This is why the California Trucking Association, which represents 2,000 companies, strongly opposes any roll backs to the rule. 

Various studies have shown key pollutants cut in half in recent years in some of the most polluted areas of the state (see here for example). While we celebrate these improvements, we need to stay on track to eliminate diesel pollution as quickly as possible, given the terrible health toll that it takes.  Our work is only halfway done.  If a cigarette was cut in half, smoking it would remain harmful to your health.   ARB should continue working to clear all the smoke, including diesel smoke, by moving forward with a strong diesel truck rule until every last tailpipe is cleaned up.