‘Magic Bullet’ Was Used on Melons : Temik Rated as the Most Toxic U.S. Pesticide
Aldicarb, the potent insecticide marketed exclusively by the Union Carbide Corp. under the trade name Temik, is the most toxic agricultural chemical sold in the United States, as measured by the dose needed to kill test animals.
So effective is the chemical that it sometimes has been called it a “magic bullet” for its ability to destroy a variety of insect pests.
In stunningly small amounts, aldicarb also can produce illness in humans, as was shown last week when scores of people throughout the West reported suffering dizziness, stomach cramps and diarrhea after eating melons believed tainted by aldicarb residues.
Although aldicarb poisonings from tainted food apparently are rare, about 10 to 15 poisoning cases are reported each year in California among pesticide applicators, according to Keith Maddy, chief of health and safety for the state Department of Food and Agriculture’s pesticide management program. Maddy said these victims, like many of those poisoned by the melons, usually recover in a matter of hours.
Maddy said that there have been no confirmed cases of deaths resulting from aldicarb poisoning in California but that the chemical may have contributed to the death in 1981 of a farm worker who was run over by a tractor while lying in a field near Davis. The worker had been burning empty bags of Temik shortly before the accident, raising suspicions that he had been overcome by toxic smoke.
Attacks Nervous System
Unlike some other controversial pesticides, however, aldicarb is not suspected of causing cancer or birth defects.
Aldicarb is a member of the carbamate group of compounds, which kill insects by attacking their nervous systems.
Like some other carbamates, aldicarb is produced by chemical reactions involving phosgene, the World War I nerve gas, and methyl isocyanate, the gas that killed more than 2,000 people and injured more than 200,000 last December at the Union Carbide pesticide plant in Bhopal, India.
Phosgene and methyl isocyanate are intermediary agents in aldicarb manufacturing but do not appear in the finished product.
In 1979, several years after aldicarb was approved for use on potatoes, it was found in domestic wells in potato-growing areas of Long Island, N.Y. Union Carbide, which has supplied water filters to about 2,000 Long Island families with aldicarb-contaminated wells, faces a class-action lawsuit by dozens of the residents.
The company has also furnished filters to owners of about 100 other wells in several other states, where aldicarb been used on cotton and ornamental plants and on such food crops as sweet potatoes, sugar beets, peanuts, pecans and citrus fruits. Four of those wells are in the unincorporated community of Smith River in Del Norte County, where aldicarb was used by lily growers until ground water problems were discovered in 1983, a county health official said.
Safety Defended
Union Carbide officials defend the safety of Temik, pointing out that it has not been associated with long-term health problems and is made only in granules that are incorporated in soil, eliminating the problem of vapor drift that occurs with pesticide sprays.
Although they have provided water filters to people whose wells have been tainted, company officials contend that the contaminant levels are much too low to cause health problems.
“It was a management decision to (provide the filters) and to relieve any concern that those people might have,” a Union Carbide official said.
Company officials said the trade name Temik was chosen because the chemical is a systemic insecticide--one that is readily taken up by the roots and distributed through the plant to kill attacking insects.
The chemical is not approved for use on melons, and the food crops to which it can be applied generally are processed or cooked before they are put on the table, thus eliminating or reducing aldicarb residues. Melons are served raw, and one state official said this might explain why enough of the pesticide remained to make people sick.
‘Simplistic, Naive’
Lawrie Mott, a project scientist with the Natural Resources Defense Council and member of an Environmental Protection Agency pesticide advisory committee, said the melon flap points out the “simplistic” and “naive” quality of pesticide regulation, which relies on label warnings and instructions on use as enforcement tools.
Mott said she believes that the use of pesticides on unapproved crops or in amounts exceeding label directions “happens all the time” and goes “completely undetected.” In these cases, she said, there are no acute illnesses, but unwitting consumers may face a higher long-term health risk.
The aldicarb exposures became evident “only because Temik is so acutely poisonous that you see effects in humans” from very small amounts, Mott said.
