OAKLAND — Lung-damaging diesel air pollution at the Port of Oakland is down dramatically since a state law forced truckers to use cleaner burning engines starting in 2010, according to new data from a team of UC Berkeley researchers.

And the gains in clean air likely are even greater because the law’s emission limits became more stringent at the beginning of the year, after the study had ended, researchers said.

Health experts say the numbers are good news for residents of West Oakland, where children had the third highest hospital admission rate for asthma in the state in 2010 behind Emeryville and Barstow.

Thomas Kirchstetter, an air quality scientist at UC Berkeley and Lawrence Berkeley National Lab, and other researchers tested 2,000 trucks by dangling an air sampling device from a bridge over SeventhStreet in West Oakland, which is a route from Interstate 880 to the port. He started testing in 2009 before the 2010 law went into effect. Then he continued testing from 2010 through 2013 when trucks were required to put a diesel particle filter on their exhaust pipes.

Kirchstetter found that particulates called black carbon decreased 76 percent while nitrogen oxides fell 53 percent from 2009 to 2013.

In 2014, the new law was ratcheted up to require the 6,000 trucks going to the port each year to have 2007 or newer model engines that produce much less pollution than those with the filters. Kirchstetter has not studied the air since those regulations started but “we’ll definitely see further reductions when we do,” he said.

Health experts say the decrease in port pollution likely is good news for West Oakland residents, but it’s too soon to tell.

“It is very encouraging that they have decreased pollution from diesel emissions,” said Washington Burns, executive director of the Northern California Breathmobile, a mobile asthma treatment clinic which operates out of the Prescott-Joseph Center, a few blocks from the entrance to the port. “But I think we have to wait several more years to know for sure.”

Burns said anecdotally asthma among children in West Oakland has increased in recent years because more people are reporting it. His Breathmobile makes regular visits to schools in Alameda County including the Preparatory Literary Academy of Cultural Excellence that is near the entrance to the port.
“When we first came here to the community in 2009 there was about 20 percent of children who had asthma,” Burns said. “Now the schools are telling us it’s higher.”
Nevertheless, it is well documented that diesel fumes can cause cancer, premature death and other health problems. California designated diesel pollution a “toxic air contaminant” in 1998.
“Anything that improves the air pollution is going to improve health,” said Brenda Yamashita, director of chronic disease for the Alameda County Health Department. “It’s probably not going to affect the number of people diagnosed, but it could reduce asthma episodes.”
The Port of Oakland came to similar conclusions about the reduction of diesel truck pollution by studying data on how much pollution truck engines from specific years produce. From 2005 to 2012 as truck engine exhaust got cleaner, diesel particulate matter should have dropped 88 percent and nitrogen oxides 60 percent, said Tim Leong, an environmental scientist at the port.
“The environmental benefits are pretty tremendous when you go to these newer engines,” Leong said. “So we have measurable differences today from just a few years ago. Our efforts to work with the trucking community have paid off.”
In a separate study to see how a different set of pollution requirements on diesel trucks that don’t go to ports is affecting the air, Kirchstetter is doing an air study in the eastbound lanes of the Caldecott Tunnel. One set of readings was taken last summer and more will be taken in 2015 and 2017, he said.
Contact Reporter Doug Oakley at 925-234-1699. Follow him on Twitter atwww.twitter.com/douglasoakley