Half the cocaine being seized in Florida by the end of last year contained a cancer-causing chemical, according to the Drug Enforcement Administration, and officials said they fear that more than half the cocaine now on the streets nationwide is contaminated with the carcinogen.
DEA Administrator John C. Lawn said he views the situation as "extremely dangerous," although he said the extent of the health threat will not be known until the federal Centers for Disease Control in Atlanta completes an investigation. Lawn said results of the DEA investigation have been forwarded to the CDC.
Lawn said that because of a crackdown on the chemicals previously used in making cocaine, drug traffickers are processing the drug with benzene, known to cause leukemia and genetic damage in humans and easily absorbed into the body through the lungs and through skin contact.
John F. Phelps, chief of DEA's Cocaine Investigations Section, said his agency has found "significant" amounts of benzene in samples of cocaine seized since April -- as it became more difficult for cocaine processors to obtain ether, normally used as an anesthetic but also used in refining cocaine.
Phelps said he wants to wait for results of the CDC study, expected within the next few weeks, before evaluating the danger. "We want to be careful that we have our facts right," Phelps said. "We don't want this to be seen as some kind of government scare tactic."
By last December, Phelps said, benzene was being found in 50 percent of the samples tested. He said most of the samples were from shipments seized in Florida, the major distribution point for cocaine entering the United States.
The DEA estimates that 20 million Americans have used cocaine and that 4 million to 5 million are regular users who may now be systematically exposing themselves to benzene. Phelps said the early DEA tests would lead him to think that at least half the cocaine in circulation in the United States is contaminated with the chemical.
Dr. Sidney Wolfe, head of the Public Citizen Health Research Group, called benzene an "extremely potent carcinogen" that "has been known for two decades to cause leukemia in humans."
He said the chemical, which also causes genetic damage, is "very dangerous at low levels, even levels of one part per million or less."
Because of the widespread recognition that it is dangerous, benzene has been removed over the last decade from products such as cleaning fluid and paint thinner.
The use of benzene in consumer products has been banned by the Consumer Product Safety Commission. Its main use, according to a specialist at the Environmental Protection Agency, is in gasoline. In addition, scientific researchers use benzene in laboratories, but they are required to keep the substance under a well-ventilated hood.
The EPA source said the cocaine itself remains the most immediate health risk to cocaine users, while leukemia and other effects of benzene might not show up for 20 to 40 years. "If you're regularly sniffing cocaine, your brain is probably going to get fried before the leukemia gets you," he said.
Wolfe said that because benzene can be absorbed by the lungs and directly through the skin, the cocaine processors who handle the chemicals face a greater health risk than people who are simply users.
James Luke, former D.C. medical examiner, called benzene "very dangerous. The more exposure you have, the more dangerous."
Environmentalist Lewis Regenstein, in his book "America the Poisoned," cites studies that link cases of leukemia to workers' exposure to benzene.
He cited a study by the National Institute for Occupational Safety and Health showing that worker exposure to six chemicals -- arsenic, asbestos, benzene, chlorine, nickel and petroleum distillates -- is thought to account for 20 percent to 38 percent of the more than 600,000 cases of cancer diagnosed in this country each year.
Phelps said that the DEA began in 1980 to look into the export of ether as a chemical for processing cocaine. "We discovered that of all the ether being shipped into Colombia," he said, "98 percent appeared to be used for cocaine processing and only 2 percent for legitimate medical purposes."
Cocaine paste is processed with ether and other chemicals to obtain cocaine hydrochloride, the final product.
The DEA worked with ether manufacturers and drug-producing countries to set up a permit system for exporting ether. The sysem has effectively blocked drug traffickers' access to ether.
Because of widespread seizures of the illegally exported ether, Lawn said, the price of ether to the drug traffickers soared from $180-$200 per barrel to $8,000-$10,000 per barrel. One barrel of ether will process 12 to 15 kilograms of cocaine.
Phelps said the DEA began the cocaine study to make sure the agency was effectively cutting off supplies of ether.
"We anticipated that they would go to alternate chemicals, but we didn't anticipate anything as deadly as benzene," he said.
Until April, Phelps said, there was no indication that cocaine was being processed with benzene. By November, 50 percent of the cocaine samples tested by DEA showed benzene contamination, and in December the figure again was 50 percent.
The DEA study has also found increasing amounts of several other chemicals in the cocaine samples tested, including toluene, methyl ethyl ketone and methylene chloride. Wolfe said that small amounts of toluene cause no major known health problems; methyl ethyl ketone causes skin irritations; and methylene chloride is classified as a carcinogen, although it is not as potent as benzene. The Food and Drug Administration has proposed banning the use of methylene chloride in cosmetics.