Lab Says Test Falsely Found Herbicide in Firefighters

An investigation into a fire that sickened dozens of Los Angeles County firefighters has prompted one of the country’s top toxicology labs to determine that one of its tests might wrongly indicate exposure to a dangerous herbicide.

As a result, experts believe that there were no toxic amounts of chemicals present at the mysterious fire last fall that burned for two weeks at a green waste dump on the site of a former oil refinery in Santa Clarita.

“You’re not seeing a level of unusual chemicals that would cause a problem,” said Dr. Joseph Fedoruk, who has conducted an extensive, 11-month study of firefighters involved in the blaze. “There isn’t an unusual pattern of chemical toxicity.”

The lab in question, Pennsylvania-based National Medical Services, is contacting medical officials throughout the country to warn of problems with the test, which confuses caffeine and the herbicide cyanazine, suspected of causing birth defects and cancer.

At least 16 of the 200 Los Angeles County firefighters who battled the blaze at Santa Clarita Greenwaste tested positive for high levels of cyanazine in their bodies. The lab has concluded that the test was mistaken.

Although the numbers are unclear, at least 100 people nationwide, including the Los Angeles firefighters, have tested positive in the last two years for exposure to the herbicide, which is being taken off the market at the end of this year because of its potential danger.

Lab officials said they have corrected the problem, which they believe only applies to tests conducted after January 1998. The trouble was traced to a gas chromatography machine used at that time to perform the test.

“For a lab like ours, this is significant,” said Robert Middleberg, laboratory director for the company, which frequently provides test results for law enforcement agencies and experts to testify in trials, including O.J. Simpson’s. “It impacts on people’s lives. Whether it’s one or a hundred, it’s very important to us.”

All told, more than 60 firefighters filed workers’ compensation claims stemming from the blaze. Tests from blood, water, soil and smoke showed trace amounts of a variety of dangerous chemicals, including arsenic, lead and phenol.

This summer, Fedoruk told firefighters that none of those dangerous chemicals were present in high enough amounts to cause harm. But he continued to puzzle over tests showing high levels of cyanazine in the firefighters’ blood.

As a result, he asked National Medical Services to review its testing procedures. That review showed that caffeine can fool the test, producing a false positive.

Fedoruk, Middleberg and other experts said the discovery means that the firefighters almost certainly were not exposed to dangerous amounts of the herbicide, manufactured by DuPont Co. under the trade name Bladex. Instead, they believe that coffee or food containing caffeine caused the test to falsely report cyanazine exposure.

But Gary Ordog, chief toxicologist for Henry Mayo Newhall Memorial Hospital, who has treated many of the firefighters, said some of them don’t eat or drink anything with caffeine in it.

Ordog said at least 100 firefighters tested positive for exposure to differing levels of cyanazine. He said the chemical, mainly used to treat crops, may have been present at the dump, which collected yard clippings and other green waste from throughout Los Angeles.

The firefighters involved have complained of various symptoms, including debilitating fatigue, headaches and impotence. One remains on medical leave.

“I still think they have cyanazine, especially . . . one who never had coffee,” Ordog said. “I don’t know how invalid those results are.”

Fedoruk said smoke inhalation may have sickened many of those who fought the blaze. He said he plans to finalize his results in a report to the county later this year.

Chemists and toxicologists say problems with false positives happen occasionally. For instance, Salt Lake City-based ARUP Laboratories, another of the country’s leading toxicology facilities, discovered that one of its tests falsely reported that a person had taken a narcotic called meperidene. The error was quickly corrected, an ARUP official said.

With more than 20 million compounds recognized by chemists, confusion is bound to happen in such tests, several experts said.