May 7, 2008 11:55 pm US/Pacific 
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Scientists Question Safety Of Apple Moth Pesticide
(CBS 5) The State of
California has said the pesticide it plans to spray to eradicate the light brown
apple moth is safe. But if their claim is true, why did more than 600 people
complain of health effects after the aerial spraying of Monterey and Santa Cruz
Counties last year? Two Monterey area scientists told CBS 5 Investigates they
have the answer.
To the many people living in Monterey and Santa Cruz
Counties, there is no doubt that the pesticide sprayed over their communities
caused them health problems.
"The complaints just kept pouring in," said
Mike Lynberg, who set up a grass roots hotline.
But state agriculture
officials say the spraying is safe. It contains a pheromone encased in tiny
plastic microcapsules. A key question is the size of those
microcapsules.
Why is that important? Because if those particles are very
tiny, 10 microns in size or smaller, experts say they can be inhaled into the
deep lungs, where there is a higher risk for causing health effects.
In
public documents and meetings, state agriculture officials have repeatedly
assured residents that the particles in the spray, on average, are much larger
than 10 microns. At a recent Berkeley City Council meeting, state toxicologist
Dr. David Ting told residents the average particle size was 90
microns.
But back in Santa Cruz and Monterey, where the spraying already
happened, and dozens complained about health effects, two local engineers
wondered.
Dennis Knepp and Jeff Haferman, who is also a city council
member, decided to try to figure out how big the microcapsules in that spray
really were. "We wanted to know how many of these little tiny things there
were," said Haferman.
Scientific charts put out by the state show that
only a small percentage, just 1.2 percent of the microcapsules are 10 micron
size or below. But Haferman wasn't impressed with their work.
"They had
done some very rough stuff, just slapped together, with some really crude
assumptions," Haferman said.
When Knepp and Haferman did their own
analysis, they found potentially many more inhalable particles in the spray. In
fact, they say fully half of the particles were 10.1 micron size or
below.
"It was obvious from the first glance at this curve, and it was
astounding that the CDFA didn't notice that," Knepp said.
Why are the
numbers so different? The scientists say because the state did a volume
calculation.
Yet in a consensus report last year, state agencies used the
Agriculture Department's analysis to justify not doing some health studies,
saying, "Since the microcapsule particles are very large by inhalation
standards…an inhalation toxicity study would not be useful and was not
conducted."
"They were using the fact to justify not performing an
inhalation toxicity study," Knepp said.
In a letter to the scientists, an
Agriculture Department branch chief defended the state's methodology, saying his
estimates show the number of small particles "is not a high concentration" and
falls within state air quality standards. And a department spokesman further
told CBS 5 Investigates, people "…should be able to breathe the product and not
get sick."
But the state has now reversed position, and says it will do
an inhalation study.
"It leaves us the question how much can we trust any
of the science they've done, and I don't trust them to do future experiments
either," Knepp said.
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