28 Pesticides on Dietary Cancer High Risk List

The National Research Council said Wednesday that 28 pesticides found in 15 commonly eaten foods from tomatoes to grapes may pose the greatest pesticide-caused dietary cancer risk to humans and urged the U.S. Environmental Protection Agency to focus its regulatory efforts on them.

The findings, announced in Washington after a two-year study requested by the EPA, are expected to spur new efforts in Congress to overhaul the nation’s pesticide regulation laws. Leaders of the House Agriculture Committee introduced a new bill on Tuesday and a Senate bill is expected after the Memorial Day recess.

The research council, an arm of the prestigious National Academy of Sciences, noted that one in four Americans will contract cancer during their lifetimes. The council said that if concentrations of the pesticides were consistently as high as legally permitted there theoretically could be as many as 1.46 million additional cases of tumors in the United States over the next 70 years.

Not all of those tumor cases would be fatal. Arthur Upton of New York University Medical Center, a member of the study panel, said that toxic pesticides might cause up to 400 cancer deaths per year. Upton was director of the National Cancer Institute between 1977 and 1979.

In releasing its report, the council said its risk assessment should not be used to unduly raise alarm among consumers about specific crops and animal products.

“The potential cancer risks from pesticides in the diet are small in comparison to other known causes of cancer,” Ray Thornton, president of the University of Arkansas and chairman of the council’s committee told reporters in Washington.

Instead, Thornton said the findings point to pesticides and crops where the EPA should concentrate its enforcement and regulatory efforts. “We recommend that EPA identify and focus its regulatory effort on the most worrisome pesticides used on the most frequently eaten crops,” Thornton later told the Senate Agricultural Committee.

The EPA has long been criticized for failing to adequately regulate pesticides and to test previously approved pesticides under more rigorous standards in effect today. Previously licensed pesticides account for 90% of the risk attributed to the 28 pesticides examined by the council.

Together, the 28 pesticides and 15 foods examined by the council account for 80% of all estimated dietary tumor risks from pesticide residues in food, it said. Most of those pesticides were approved for use before 1978 when the EPA began requiring more rigorous tests.

The 15 foods, in order of presumed risk, are tomatoes, beef, potatoes, oranges, lettuce, apples, peaches, pork, wheat, soybeans, beans, carrots, chicken, corn (bran, grain) and grapes.

‘Worst-Case Scenario’

The council emphasized that the risk estimate represented a “worst-case” scenario based on the theoretical assumption that pesticide levels in the 15 foods would always be found at the maximum permissible concentrations and that the foods would be eaten daily over a 70-year lifetime. The council said that risks may be lower or higher, adding that while actual concentrations of pesticide residues in foods are often lower than the maximum tolerances allowed, there is little information on the health effects of many of the compounds now in widespread use.

The report sparked calls Wednesday for changes in the nation’s pesticide laws by both environmental groups and the nation’s multi-billion-dollar agricultural chemical industry.

“The NAS report dramatically documents that the problem of carcinogenic pesticides in food is one of staggering proportions--far worse than previously believed,” Lawrie Mott, senior scientist with the Natural Resources Defense Council said Wednesday.

Consumers Union, publisher of Consumer Reports magazine, said that the findings pointed to the EPA’s limited knowledge about pesticide risks and said there was a pressing need for congressional action to accelerate the EPA’s regulatory action.

Quicker Review

On Capitol Hill, John Moore, assistant EPA administrator, told the Senate Agricultural Committee that the EPA needed additional resources in order to undertake a quicker review of untested pesticides that are now on the market.

But, the Western Growers Assn., headquartered in Irvine, warned that the report could create a panic. “The food grown in the United States is safe and healthy,” association President David Moore said. “The data published in the academy’s report can be easily distorted and misused, comparable to an automatic weapon in the hands of a terrorist.”

In Washington, Dennis Heldman of the National Food Processors Assn., said the study overstated pesticide risks by 100 to 1,000 times. He told the Senate Agriculture Committee that there were no detectable levels of pesticides in 99% of actual food samples.

The National Agricultural Chemicals Assn. called for a “high-level panel” to study the report released by the National Research Council.

Heightened Detection

Two years ago, the EPA asked the council to study the EPA’s methods for setting tolerances for pesticide residues in food. Since enactment of the Federal Food, Drug and Cosmetic Act in 1954, science has been able to detect increasingly smaller amounts of residues in food. The heightened detection ability has posed a regulatory dilemma for the EPA.

Under the the so-called Delaney Clause of the Food, Drug and Cosmetic Act, the EPA is prohibited from approving any food additive that has been found to “induce cancer.” The EPA has interpreted that to mean to induce either benign or malignant tumors. The EPA has also defined pesticides as food additives in processed foods. Processing includes canning, cooking, freezing, dehydrating or milling. Cancer-causing pesticides in fresh foods, as opposed to processed foods, are not covered by the Delaney Clause.

As the EPA begins the process of re-registering pesticides already on the market, the agricultural chemical industry faces the real possibility that “a significant number” of products will be banned because they cannot meet the Delaney Clause’s “zero-risk” standard.

The National Research Council said Wednesday that standard should be changed to “negligible risk” but should be applied across the board to both raw food and processed food. Currently, the zero-risk standard applies only to processed food.

Could Eliminate Risks

The council said the new standard would “virtually eliminate” the potential dietary cancer risks estimated for the 28 pesticides.

On the other hand, the council said that a decision to keep the Delaney Clause’s zero-risk standard to processed food but not fresh food would eliminate only half of the estimated cancer risk from the compounds.

In some cases, that could mean forbidding a new pesticide on the market that could replace an older, more toxic compound. The older compound, however, would remain on the market at least until its review.

Consumers Union noted that the EPA has reassessed only 115 pesticides for their oncogenicity, or tumor causing potential--less than half of the pesticides currently approved for use on food.

Clause Never Invoked

The National Research Council said Wednesday that the EPA has not once invoked the Delaney Clause to revoke a pesticide. Currently, the EPA has complete residue chemistry on less than 25% of pesticides used on foods.

Nearly all cultivated cropland in the United States is treated annually with at least one herbicide, and about 15% of this land is also treated with a fungicide. While some crops such as hay and small grains do not depend on any pesticide, virtually all perishable fresh fruits and vegetables depend heavily on pesticides. Some are sprayed at least a dozen or more times each with six or more different active ingredients.

Of an estimated 480 million pounds of herbicides used annually in the United States, 300 million pounds are presumed by the EPA to be tumor-causing or potentially tumor-causing.

Among the 28 pesticides studied, 12 accounted for 96% of the dietary risk calculated by the council. Those 12 include linuron, zineb, captafol, captan, maneb, permethrin, mancozeb, folpet, chlordimeform, chlorothalomil, metiram and benomyl.

In addition, about 90% of all agricultural fungicides show positive results in tests to detect tumors. These fungicides represent from 70 to 75 million of the 80 million pounds of all fungicides applied annually in the United States.