People like their apples red, which is one reason many apple growers spray their orchards with daminozide, a pesticide that makes apples redder, firmer and less likely to drop off the tree before the grower is ready to pick them. Unfortunately -- for growers and consumers alike -- daminozide is, according to the Environmental Protection Agency, a cancer-causing chemical that produces a variety of tumors in a variety of laboratory animals.
Now, seven years after it received the results of studies supporting daminozide's carcinogenicity, the EPA is proposing to ban the chemical, alleging that lifetime exposure to daminozide residues in food may result in unreasonable health risks. Before all of the steps necessary to remove the chemical from the market are taken, growers and the manufacturer of daminozide -- Uniroyal Co. of Middlebury, Conn. -- may request an administrative hearing before the agency to protest the ban. In any case, during the administrative process, daminozide, marketed under the trade name Alar, stays on the market.
Uniroyal has said the studies on which the EPA proposal is based are inadequate, and that daminozide does not pose a risk to human health. Last month, EPA asked a scientific advisory panel to review the scientific basis for EPA's proposed ban, and last week Uniroyal asked the panel to recommend that the agency withhold action until ongoing animal studies are completed in 1988.
The panel agreed with Uniroyal's position and told EPA that EPA needs more data to adequately assess daminozide's risk. It said the current studies do raise concerns, and took EPA to task for not requesting additional studies on the chemical soon after results of the first test were available.
EPA officials say the risks of daminozide are not in the short run, but from continued exposure over a lifetime period. If a hazard is considered great enough, EPA has the authority to suspend use of the chemical during the hearing process. But in a written statement, John Moore, the EPA's assistant administrator for pesticides and toxic substances, said the risk to public health during the time necessary to cancel uses of the product will be minimal. "I do not have any immediate concern about existing food products that may contain daminozide residues," he said.
In the agency notice announcing a special review of the chemical last year, EPA expressed concern that daminozide residues have been found in products commonly consumed by infants and children, such as apple juice and applesauce. Residues of daminozide break down into an even more potent carcinogen, UDMH (unsymmetrical 1, 1-dimethylhydrazine), especially when the apples are boiled to make applesauce according to the EPA notice.
In an agency fact sheet issued along with the proposed ban in August of this year, EPA said, "people who are concerned, especially about their young children's consumption of apples and apple products, may make the personal choice to limit their consumption of apples and apple products." In its scientific analyses of the data, EPA says it could not estimate the risks of daminozide and UDMH for infants and children because their diets are so different from adult diets and do not represent lifetime exposure.
"We don't feel (daminozide) is a danger to children" says Rene Potosky, manager of public relations for Uniroyal Chemical. Potosky says that the firm has questions about the significance for adults and children of the residues found in apples and apple products, and disagrees with EPA's methods of estimating of average residues expected to be found in such products. "Our own scientists, when they looked at the residue data were not concerned," she said, pointing out that the EPA scientific panel "had serious problems with how the data were collected and analysed" by the agency. EPA residue estimates indicate a high level of dietary exposure to daminozide but Uniroyal says these estimates are seven times too high.
Dr. Bela Toth, a pathologist at the Eppley Institute, University of Nebraska Medical Center in Omaha, conducted the first study, implicating daminozide as a cancer causing agent in 1977. He calls the pesticide "a strong and potent chemical carcinogen," saying exposure of young children to the chemical warrants special attention since it is widely accepted that in cancer studies, "younger animals are more susceptible than older animals to carcinogenic stimulants."
First registered for use in 1963, daminozide is a systemic pesticide -- it cannot be washed off because it becomes part of the fruit's cells after it is sprayed on trees. Daminozide does not actually kill pests. It is a member of a class of pesticides called plant growth regulators that do just that -- affect the way the tree and its fruit grow and mature. About 25 percent of all apples, and 38 percent of fresh apples -- primarily mcintosh, red and golden delicious, and stayman varieties -- are treated with daminozide.
For mcintosh apples alone, the EPA estimates that as much as 35 percent of the crop could be lost without the use of daminozide because of apples that drop from the tree prematurely and subsequently crack and bruise. When applied to red and golden delicious apples, daminozide delays apple maturity, increasing storage life and profitability. In fact, the EPA estimates, apple growers stand to lose $30 million in the first year daminozide is banned. For consumers, according to the EPA, the supply of fresh apples will drop by 4 to 7 percent, and costs could increase as much as $1 to $1.90 a bushel. And also according to the EPA, about 75 percent of the 825,000 pounds of daminozide used annually is applied to apples; 12 percent is used on peanuts; and the remainder is used on other fruits and vegetables, including tart cherries and concord grapes.
Toth's 1977 carcinogenicity findings were later supported by a 1978 National Cancer Institute study, according to EPA. It was not until July 1984 that the EPA initiated a "special review" of the chemical, a situation Toth calls "deplorable." One EPA official blames the delay on the agency's limited resources, saying EPA scientists have concerns about a number of pesticides and attempt to deal with them in the order of their greatest risk. "The fact is, we don't have the resources to deal with them all at once," he said.
But the lengthy delays that are common to such proceedings have enraged environmental and consumer groups, which are supporting amendments to the pesticide law that would place tighter deadlines on the agency when taking actions to review the safety of registered pesticides.
The importance of daminozide to the apple-growing industry is underscored by the fact that there is no substitute chemical that will provide all of daminozide's benefits. In comments filed with the EPA, the Washington State Horticultural Association stated flatly, "As an industry, we must have the use of Alar to survive."