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SCCA Magazine |
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SCCA Magazine March-April 2010 |
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The science is NOT “settled”
CARB Science Symposium reveals
significant flaws in diesel regulations
The long-awaited Science Symposium held by
the California Air Resources Board (CARB) on
February 26 proved two things for sure: (1)
The scientific evidence behind CARB
rules on diesel equipment is flawed. (2)The scientific community is divided on
the research that supports these rules. At the symposium, it was clear – the science
is not “settled.” The day-long event allowed an
open discussion of a large number of studies
where the key findings were debated instead of
rubberstamped, as in the past.
Central to the
discussion was the fact that CARB has ignored
studies specific to California, relying on
national studies of diesel particulate matter
(PM 2.5). (Emissions appear to have a greater
impact on health in the Northeast.)
PM does not
impact life expectancy
“Studies of California
alone show diesel particulate matter does not
impact life expectancy in the state,” says Dr.
James Enstrom, president of the Scientific
Integrity Institute at the University of
California, Los Angeles. “My primary concern is
not how this has been discussed but how these
studies have been turned into regulations that
affect diesel trucks and other equipment.”
Enstrom’s studies examining only California data
found diesel emissions had a small impact on
health in California between 1973 and 1982. His
second study for 1983 to 2005 found “no risk at
all” associated with exposure to PM emissions.
Other studies were presented at the symposium by
scientists in epidemiology (the study of factors
affecting the health and illness of populations)
and toxicology (the study of adverse effects of
chemicals on living organisms) on the effects of
PM 2.5 on human health. One of the most
revealing was presented by Dr Robert Phalen, a
toxicologist from the University of California,
Irvine, and member of the Federal Environmental
Protection Agency’s (EPA) Scientific Review
Panel. Phalen explained that PM 2.5 is
not a single substance; rather, it’s a “mass,” a
measurement of fine particles in the air that
includes different chemical components in
different geographic areas.
In California, and
particularly in arid Southern California, a
large part of that mass is dust. Phalen made the
case that CARB’s diesel emissions regulations
will not improve health in the state and will
result in significant economic harm.
“If you
really want to hurt people’s health, put them
below the poverty line,” says Phalen. “That’s
the highest risk group in the United States.”
Even scientists supported by CARB research
grants questioned the methodology used to
measure air pollution. Most studies of PM2.5 are
based on CARB and local air district filters
that collect all kinds of things. “We don’t
really know what the emissions are,” says Dr.
Michael Jerrett, a University of California,
Berkeley, professor.
Only one study presented
demonstrated that PM2.5 has a relative
risk (a statistical measurement of causation)
greater than 2. This is a critical measurement
in both epidemiology and toxicology – and is
incorporated into requirements for admissibility
as evidence in the federal courts. The threshold
for concluding an agent was more likely than not
the cause of an individual’s disease is a
relative risk greater than 2; a relative risk of
1 means the agent has no effect on the incidence
of disease. When relative risk reaches 2, the
agent is responsible for the same number of
cases of disease as all other causes. A relative
risk of 2 implies a 50 percent likelihood that
an exposed individual’s disease was caused by
the agent. Smoking, for example, has a relative
risk of 8 to 10 as a cause of lung cancer.
The
Tran scandal
The symposium was scheduled after
it was revealed CARB staff member Hein Tran, who
claimed to hold a doctorate in statistics from
the University of California, Davis, actually
had a PhD from an on-line diploma mill run by an
alleged pedophile. Tran was responsible for
compiling epidemiological studies in support of
the need for diesel equipment regulation.
Later,
CARB Chairperson Mary Nichols, top
administrators at the agency and two board
members admitted to having hid Tran’s credential
scam and keeping the information from other
board members. CARB board member Dr. John Telles,
a Fresno cardiologist, responded that the fraud
should force the board to recall the diesel
rules until a valid scientific basis was
established. Although, CARB rejected Telles’
motion on a 7-2 vote, it set aside the Tran
study, called for the symposium and directed
staff to prepare new studies.
Southern
California Contractors Association (SCCA)
remains committed to supporting air quality
regulations warranted by accurate scientific
studies and to opposing unnecessary and
oppressive rules that are not based on proven
studies. Watch the symposium at www.sccaweb.org.
Click on “CARB Science Symposium.”
– By William
E. Davis, Executive Vice President, SCCA
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