Caltrans to Check on Dust from Weekend Bay Bridge Project
Jim Doyle, SF Chronicle
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Caltrans will monitor dust kicked up by
this weekend's demolition of a major portion of the western
approach to the Bay Bridge
amid questions about whether the project will pose a health
hazard for people living nearby, officials said Wednesday.
Jack-hammering the dilapidated concrete structure and hauling it away are
likely to create a lot of dust, including
microscopic particles of crystalline silica that could harm the health of
nearby residents and construction workers.
"Wherever there's visible dust (in such demolitions),
there's usually the smaller dust as well. To
be public-health protected, there should be air-quality monitoring," said
John Balmes, a professor of medicine at UCSF and director of the university's
Center for Occupational and Environmental Health. The problem, Balmes said, is
that Caltrans does not know whether the dust
created at the demolition site may constitute a health threat, because the
agency did not monitor the air quality during previous demolitions for the Bay Bridge seismic project.
Silica, a hard mineral found in sand and rock, can be hazardous when it is
pulverized into fine particles of airborne dust — and
repeated or prolonged exposure has been linked to respiratory
ailments including silicosis and lung cancer.
The potential health hazard "really depends on how
much dust is being generated that is of the size that can make
it into the lungs," Balmes said.
Caltrans spokesman Bart Ney confirmed the agency did not
monitor the air quality while its previous demolition work on
the bridge's western approach was occurring.
"We're not required to monitor the air quality,"
he said. But, he added, the agency took samples after a demolition this summer
and plans to monitor the air quality of this weekend's
Because the seismic retrofit project is an emergency, Caltrans
was exempted from undertaking an environmental impact report on
its demolitions for the bridge's western approach.
In 2003, Caltrans began the seismic retrofit of the
mile-long stretch of Interstate 80 between the San Francisco anchorage and Fifth Street. The $429
million project, which continues through 2009, involves
demolishing and replacing the original roadways, including double-deck sections
that begin at Third Street.
The latest demolition, which begins Friday at midnight, will continue
around-the-clock through the Labor Day weekend and requires
barring eastbound traffic on the bridge until
5 a.m. Tuesday. It involves sections of the elevated approach near Beale and
Second streets in a South of Market neighborhood that is filled with
Ney said the agency's contractor, Tutor-Saliba Corp. of Sylmar, is taking
precautions to reduce the amount of fugitive dust
by using numerous water trucks and fire hydrants to keep the
demolition area wetted down, and also employing tall screening around the demolition
Jack Colbourn, a spokesman for the Bay Area Air Quality
Management District, said his agency has received only a few complaints from
residents about the Bay
demolitions. He added that the district's inspectors have a limited role of
"making sure that the operator is wetting down the area and washing down
the trucks and equipment before they leave that area, so that the dust
is not flying."
An inspector for Cal/OSHA, the state's workplace safety agency, will observe
this weekend's demolition, spokesman Dean Fryer said.
"We've been working with Caltrans for the last three
weeks preparing for this, and will have a Cal/OSHA consultant out there this weekend,"
Fryer said. "We're looking at this one because it's the largest demolition
of the project."
Michael Green, executive director of the Oakland-based Center for
Environmental Health, said he also has concerns about the project.
Green said he visited a Caltrans demolition on
the bridge's western approach several weeks ago near Stillman
and Fourth streets.
"I was shocked to see how much dust
there was," Green said. "There was a ton of dust. I
don't know how much crystalline silica was in that dust."
Green recommended that residents who live near the demolition zone
"keep their windows closed. Vulnerable populations like the elderly and
the young and people with compromised immune systems should be especially
cautious. I wouldn't hang around the neighborhood."
UCSF's Balmes also noted "there are dust
masks that can be worn that are very effective in decreasing the risk of
exposure to small particles."