Claims That Tie Leukemia to Malathion Are Rebutted : Health: Top county official scolds Group Against Spraying People for scaring public with erroneous information.

The county’s top public health official on Thursday chided malathion opponents for suggesting there is a connection between aerial applications of the pesticide and leukemia.

State Medfly eradication officials, meanwhile, announced that the malathion-laced bait will be sprayed over Camarillo every three weeks instead of every two weeks in January and February.

Dr. Gary Feldman, Ventura County’s public health officer, said a statement made earlier this week by Terri Gaishin, a member of Group Against Spraying People, inaccurately depicts the health risks of spraying malathion over populated areas.

In particular, Feldman challenged the opponents’ use of a 1987 Yale University study that looked into possible links between malathion byproducts and leukemia.

Gaishin, a Camarillo mother who organized a protest outside Feldman’s Ventura office on Tuesday, told reporters and others gathered there that the Yale study concluded that “malathion has been shown to cause leukemia.”

But Feldman said Gaishin’s assertion is flat-out wrong. He read the same study, Feldman said, and found that the Yale researchers reached a far different conclusion.

In the study, scientists drenched human cells drawn from bone marrow with malathion and observed what happened to them, Feldman said. The replicating property of the cells was depressed for about 14 days before returning to normal, the researchers found.

The scientists speculated that there is a possibility that exposure to massive doses of malathion could cause anemia, or depression of the body’s ability to make red blood cells. That effect, however, has never been observed in clinical practice, Feldman said.

“There is absolutely no evidence at this point that would link malathion to cancer or human birth defects,” he said. “There is nothing in the literature to support that conclusion.”

Feldman said the statement by Gaishin “lowers the credibility of the GASP folks, who I think have genuine concerns.”

Feldman had agreed to review medical research into malathion after Gaishin and about 30 other GASP members picketed outside his office for two hours. The group targeted Feldman because he is charged with warning the community about possible health dangers, members said.

Feldman said he decided to go public with his criticism of Gaishin and GASP because he has fielded calls from several Camarillo residents concerned for their families’ health after reading Gaishin’s remarks.

On Thursday, Gaishin admitted that she may have incorrectly stated the study’s findings. She said she will forward the research paper to Nachman Bratbar, a toxicologist at USC-Medical Center, to ask for his interpretation of its results.

Gaishin also said she will keep fighting for a halt to spraying in Camarillo.

“Even if this leukemia study does not bear out for us, it does not change the fact that there are so many other studies that show this is not a safe program.”

Malathion spraying began shortly after the first Medfly was found Sept. 29 in a Camarillo orange grove.

The sixth spraying was successfully completed Wednesday night, a day after the scheduled application was delayed because of fog.

Cooperative Medfly Project officials said the next spraying over a 16-square-mile section of east Camarillo will begin at 9 p.m. Jan. 17. The next two treatments will take place in three-week intervals, on Feb. 7 and Feb. 28, state officials said.

The two-week schedule will be reinstated in March, officials said. Fewer applications are needed in January and February because the cooler weather lowers the Medfly’s ability to reproduce, said spokesman Doug Hendrix.

In a related action Thursday, the Board of Supervisors extended a proclamation of local emergency due to potential crop losses from the Medfly infestation for two more weeks.

The proclamation ensures that the county will be eligible for reimbursement for Medfly eradication costs from state and federal government programs.