No Major Malathion Harm Found : Health: County officials say test results reassure them that aerial spraying is safe. More than 100 Southland residents were examined after complaining of rashes.

Newly released results of the first medical tests of Southland residents exposed to the controversial pesticide malathion show that it caused no major side effects, even in people most likely to suffer allergies and asthma, health officials said.

Los Angeles County health officers, who conducted the studies on more than 100 Los Angeles and Orange County residents, said the results reassure them that the threat of health hazards was extremely low in neighborhoods that were sprayed with the pesticide between the fall of 1989 and summer of 1990. The sprayings were part of a state-sponsored effort to combat the Mediterranean fruit fly.

However, environmentalists and anti-spraying activists said they remain skeptical.

About 1.5 million Southern Californians were exposed to malathion sprayings as often as once a week.

The medical tests on residents from throughout the two counties were the first performed on people who live where aerial malathion spraying was conducted, said Dr. Paul J. Papanek Jr., who coordinated the studies as head of toxic epidemiology at the Los Angeles County Department of Health Services.

All those tested had complained of rashes after spraying in their neighborhoods, so they were considered a group more likely to suffer skin reactions than the general public. The tests were conducted between June, 1990 and January, 1991.

“The health effects are not zero, and that’s because there appear to be some people who are allergic to malathion or the bait it is mixed with,” he said. “But the allergic reactions appear to be infrequent and overall mild. By in large, they are not very often and none are very serious.”

The health department study found that:

* None of 47 people tested for skin reactions developed dermatitis or suffered skin allergies when a mixture of malathion and bait was painted on their backs in patch tests. Two children, however, suffered mild hives on their arms after scratch tests, in which the subject’s skin is “roughened up” and pricked with diluted concentrations of malathion.

* Fifteen asthmatics who live around downtown Los Angeles in malathion spray areas did not suffer any more respiratory problems than those from a control group outside spray zones. The tests found no increased blockage of airways. Some people complained of scratchy throats, which showed possible irritation, but there was no worsening of their asthma, Papanek said.

* Urine tests, which measured the amounts of pesticide people absorbed through their lungs or skin, showed concentrations were much lower than originally believed and much less than the amount that is known to cause illness.

The urine specimens were collected from 67 people in sprayed neighborhoods, including 17 Orange County residents, 37 Los Angeles County residents, five children at a Los Angeles County day-care center and eight agricultural workers. Most of the participants had called their local health department to complain about health problems from the aerial spraying.

Some showed minute amounts of malathion in their urine, but Papanek’s report said these levels were barely detectable and were hundreds of times lower than levels considered great enough to cause illness.

“It takes a large amount to be poisoned, and we’re not even close to poisoning,” he said. “Even the highest levels are on the low side compared to a toxic dose.”

State agricultural officials repeatedly said during the nine months of spraying that the risk to the public was minimal, but local health departments received several thousand complaints of illness from residents who related their problems to the pesticide.

Groups representing California growers, who consider the Medfly a major threat to their multibillion-dollar industry, were relieved by the findings, while environmentalists and anti-spraying activists said they are not convinced of the pesticide’s safety.

Mollie Haines, a Garden Grove woman who was a vocal opponent of malathion in the Medfly battle because her neighborhood was sprayed nine times, said Tuesday that the test results did little to reassure her.

“I’m not just concerned about rashes, but long-term health effects, and no one is studying that,” she said.