State Panel Says Malathion No Serious Health Threat : Spraying: A few of the 26 experts won’t entirely rule out a slim risk of cancer from the insecticide.

A state panel of scientists and physicians has concluded that malathion spraying poses no serious health threat, after reviewing existing scientific studies, although a few of the 26 panelists are quibbling about whether they can entirely rule out a slim cancer threat.

The study group was created by the Deukmejian Administration with the hope of allaying public fears about aerial spraying of the pesticide, which has been used to help fight the spread of Mexican fruit flies in San Diego County and to eradicate Mediterranean fruit flies in Los Angeles, Orange, San Bernardino and Riverside counties.

County and state officials said Wednesday that they expect the report, which will not be completed until next month but was made available this week in draft form, to satisfy most of the public but not all critics.

“The exhaustive review confirms what we had all along believed to be true,” said Dr. James W. Stratton, a state Department of Health Services epidemiologist coordinating the panel’s work. “The small amount of malathion used in the Medfly program is not a public health risk.”

The aerial Medfly program used 2.8 ounces of the pesticide per acre each spraying, although most of the 536 square miles that were sprayed received repeated applications.

But Los Angeles City Councilman Joel Wachs, who has emerged as a leading critic of malathion spraying, dismissed the report as “nothing more than a study to validate an existing position.”

“They just rehashed old stuff rather than do any of the new studies that are desperately needed,” he said.

Meanwhile, the yearlong spaying program is on hold as Medfly eradication officials wait to see if the fruit- and vegetable-destroying pests show up in sufficient numbers in traps to justify ordering malathion-spraying helicopters aloft once again.

Since completion of the latest round of spraying late last month, officials report that only two lone flies have been trapped--one in Sherman Oaks and another in Brea.

Critics of the spraying promptly denounced the 400-page report by the Public Health Effects Advisory Committee as a whitewash and worse.

Critics focused on a possible split within the panel’s cancer subcommittee over whether a cancer risk from malathion can be entirely ruled out.

Dr. Harvey Karp, a Santa Monica pediatrician and one of two dissenters on the 12-member subcommittee, played down the apparent split. He contradicted predictions from spraying critics that he and Dr. Samuel I. Roth, a retired Woodland Hills internist, were committed to filing a minority report.

“It’s not much of a disagreement, really,” he said. “It’s just an issue of semantics. Dr. Roth and I are interpreting the definition of what constitutes a risk rather strictly.”

Karp said he and Roth, who was not available for comment, were awaiting precise data on how much malathion residents had been exposed to by spraying before determining if they would file a minority report.

“But I expect that when we get the exposure information, we will conclude that the cancer risk is negligible,” he said. “When all is said and done, we may all be in total agreement within the subcommittee.”

The draft report by the cancer subcommittee, which Stratton said reflects the majority view, concludes that “studies do not provide evidence for the carcinogenicity of malathion.”

Karp added that “all subcommittee members, including me, feel there is no strong evidence of cancer risk. There appears to be only a tiny bit of evidence, and it is weak evidence.”

Patty Prickett of Residents Against the Spraying of Pesticides said her group “expected a whitewash, and that’s what it appears we are getting.”

She noted that panelists, in their public discussions over the past six months, often cited a lack of evidence of public risk from malathion spraying.

“It seems to me if the case for the safety of spraying is not proved, then you don’t put millions of people at risk by spraying them 10 times or more,” Prickett said.

“I don’t think this group ever had any serious intent to look into the health risks,” she added.

Wachs, referring to what he termed a “major split” on the cancer subcommittee, predicted the report “would have little credibility in the community.”

He repeated charges aired at hearings he conducted recently at City Hall that “less than 15% of the people who got sick from the spraying in Los Angeles ever reported it to authorities, and there was little or no follow-up on those who did.”

“There have been so many gaps in the investigation into public health problems from the spraying that no one can draw any conclusions,” Wachs said.

The panel, named in January by State Health Director Dr. Kenneth W. Kizer, is composed of scientists, physicians, public health specialists, toxicologists and statisticians.

Dr. Stuart Siegel, co-chair and head of the department of hematology-oncology at Children’s Hospital in Los Angeles, called the panel’s work the “most comprehensive review of existing data that has ever been done, even by the federal government.”

Panelists, he said, have spent “countless hours reading and discussing virtually every significant study ever done on the subject.” Panel meetings were open to the public and were followed closely by critics of the spraying program.

Los Angeles County Agricultural Commissioner E. Leon Spaugy said Wednesday that he was “guardedly optimistic” that the yearlong Medfly infestation has been defeated with aerial malathion spraying and the release of sterile Medflies, which mate with fertile flies and produce no offspring.

But Spaugy said agricultural officials will not be confident of victory until they get through August and September--months that in prior outbreaks have proved to be times of high activity among the pests--with traps largely free of Medflies.

“We’re keeping the corks in the champagne bottles until the end of September,” he said.