Just before Thanksgiving in 1959, Americans were told that the cranberries they expected to serve with the holiday turkey might be contaminated by a chemical weed killer known to cause cancer in animals. Hardly anyone remembers that the name of the chemical was aminotriazole, but nearly everyone remembers the "cranberry crisis."
It was the first of a series of potential environmental catastrophes which have popped via the news media into the public consciousness with increasing and relentless frequency. For example, attendees at a meeting of the American Chemical Society in San Francisco last August heard a University of California scientist warn that a fireproofing chemical used in large amounts in children's pajamas might cause cancer in those children. At the same meeting, scientists alerted their colleagues to the fact that some California wines were laced with large concentrations of poisonous and possibly cancer-causing arsenic, and that cancer-causing chemicals (carcinogens) were found in several commercial lawn and garden sprays.
As each of these new and potentially deadly encroachments on our health and environment works its way up the scare scale, it supplants--in the public's mind at least--other crises that have emerged in the last twenty years or so. In 1964, the discovery of DDT's toxicity caused Rachel Carson's fears of a silent spring. In the early 1970s, mercury was revealed as threatening serious damage to the brains and bodies of this and future generations, and the frightening dangers of asbestos were publicly acknowledged. What about those crises of yesteryear? Can we stop worrying about them? Or are they still around, silently threatening us and our children with premature death? What, for example, ever happened to the cranberry crisis?
In retrospect, it doesn't look nearly so frightening as it did when then Secretary of Health, Education and Welfare Arthur Flemming announced that two shipments of cranberries from the states of Washington and Oregon contained possibly harmful levels of aminotriazole. Because animal tests showed that the weed killer caused thyroid cancer, he recommended that cranberries from those states be taken off the supermarket shelves. The move seemed reasonable enough from a bureaucratic and health point of view, but it left shoppers with no way of telling whether their Thanksgiving cranberry sauce originated in Oregon or in a "safe" state, such as New Jersey. Then, just three days before the holiday, Flemming announced that the Department of Health, Education and Welfare had developed techniques for certifying cranberry batches as good or bad. By that time, however, much of the public had decided either to abstain from cranberries until the fuss blew over or to take their chances with the risk of cancer.
The cranberry scare now seems more of a nuisance than an environmental crisis. Cranberry growers felt a slight decline in their business for several months after the aminotriazole ban, but by the following Thanksgiving, Americans had gotten over their cranberry phobia. And although the herbicide could no longer be used on food crops of any type, the growing demand for it as a weed control for roadsides, parks, and railroad rights-of-way easily offset the temporary losses experienced by aminotriazole's two manufacturers. In fact, the cranberry crisis might never have occurred if farmers in Washington and Oregon had followed the instructions on the aminotriazole bags and applied the weed killer after the berries were removed from the bushes instead of before.
Verdict: The cranberry crisis is over.
WAS RACHEL CARSON RIGHT?
Whether Rachel Carson was right when she warned about the perils of the insecticide DDT in Silent Spring has still not been completely resolved. But she might as well have been. Since her book appeared in 1962, use of DDT in this country has dwindled to a few select applications. Previously it had been sprayed indiscriminately from one end of the biosphere to the other. The series of actions against DDT, which began even before the book appeared, were based on findings that in some cases went well beyond Carson's predictions.
Unassailable evidence suggested that DDT was being carried by air, sea, and living organisms to areas as remote from the original spray site as the South Pole. The persistence of DDT, which made it so useful for the long-term control of mosquitoes in malaria areas, was also causing a long-term buildup in the fatty tissues of man and animals. The buildup started early: infants received their first taste of DDT in their mother's milk. Insects, on the other hand were developing resistance to DDT, and each time a larger killing dose was aimed at the insects in the fields, the potential threat to man and animals also increased.
Researchers soon found that virtually all terrestrial organisms had to some extent been touched by DDT. It decreased photosynthetic processes in phytoplankton and they could no longer produce enough oxygen for fish to breathe. It blocked hatching in fish and sometimes built up to lethal levels in the brains of migrating birds. DDT, by reducing the thickness of bird's eggshells, threatened the existence of ospreys, sparrowhawks, pelicans, and other birds that feed on animals contaminated with DDT.
No proof is yet available that DDT is an immediate threat to human health. A few successful suicide attempts and a number of accidental deaths have been attributed to the injection of large amounts of DDT: there have also been a few cases that indicate that large doses will cause tremors and other symptoms of nerve damage. Yet, although millions of people in malaria areas and many workers in DDT plants were exposed to relatively high concentrations of DDT for as long as twenty years, the increased exposure has apparently had no adverse health effects to date. Critics of the DDT ban, including Dr. Thomas Jukes of the University of California at Berkeley, point out that for many years some chemical plant workers were taking in a daily dose of DDT approximately 1250 times greater than what the average American was absorbing in the late sixties.
Whether DDT can or will cause cancer in man is still very difficult to pin down. Some evidence suggests that it causes tumors in rats, but probably not in other animals, including monkeys and chickens. Like other chemical carcinogens, DDT may require an incubation period of twenty years or more before the cancer it produces becomes evident. If so, those cancers may just now be starting to appear. We may NEVER know if DDT causes cancer in man, because everyone's fatty tissue contains some of the insecticide. Thus, we have no uncontaminated control population against which to measure its cancer-causing effect. Also, many of those most extensively exposed to DDT in farm and orchard were migrant workers who have now scattered beyond the reach of adequate medical follow-up.
Dr. Jukes says that the DDT boycott was chiefly an expression of "environmental chic" on the part of prosperous urban dwellers whose concern about the demise of the songbirds ignored the need for DDT among "the inarticulate majority of the world's people...who are struggling against disease and hunger. He argues that while DDT is not demonstrably harmful to human health, it has saved 5 million lives in underdeveloped areas and prevented 100 million illnesses since it was introduced in 1942. Dr. Jukes cites recent evidence from Cornell University that the thinning of eggshells was probably caused not by DDT but rather by other environmental contaminants, including mercury, or by one of the more recent worldwide pollutants, the polychlorinated biphenyls (PCBs).