March 29, 2024
BANGOR DAILY NEWS (BANGOR, MAINE

Dire predictions can be puzzling

The latest episode in the never-ending controversy over the role of chlorofluorocarbons (CFCs) in the destruction of the ozone layer has raised a serious question about how scientific debates should be conducted. Certainly legitimate differences of opinion exist over such questions as greenhouse warming, acid precipitation, and ozone layer destruction. The question is how should these differences be debated. Increasingly, it seems the scientific merits of both sides of the question are being lost as doomsday statements issued to the media by politicians, and even researchers themselves, seek to sway public opinion.

Ozone loss results from a series of complex, and poorly understood, chemical reactions. Hard data on the extent to which it is happening, and the consequences of its loss, are equally hard to come by. The danger in making premature dire predictions that fail to materialize is that all researchers in the field will lose credibility with the public. In this regard, the latest ozone scare bears a close resemblance to the Alar furor of a few years ago.

The latest ozone flap began on Jan. 20 when a NASA research plane took off from Bangor to measure the concentration of chlorine in the upper atmosphere. Chlorine results from the photodegradation of CFCs and is a major factor in the series of chemical reactions thought to cause ozone loss. The plane returned with bad news. James G. Anderson, a chemistry professor at Harvard University and the project leader, held a news conference on Feb. 3 and announced that record-high levels of chlorine monoxide were measured over Canada and northern New England during the January flights.

“If these conditions persist,” Anderson warned, “we will have a very significant loss of ozone within the Arctic polar vortex as the sun returns to the northern latitudes.” The vortex, a cold mass of air roughly centered at the North Pole, can reach as far south as New England and the United Kingdom. The implication was that spring would bring a huge hole in the ozone layer over these areas with deadly ultraviolet radiation pouring through on the inhabitants.

The reaction to Anderson’s press conference was immediate and vehement. Members of the environmental group Greenpeace draped themselves in radiation-protective jumpsuits and demonstrated for a complete and immediate ban on CFCs and all chemicals that release chlorine to the stratosphere. Sen. Albert Gore Jr., D-Tenn., introduced legislation ordering the Environmental Protection Agency to speed up U.S. phaseout of CFCs. On Feb 6, Gore made a speech from the Senate floor where he raised the specter of “an ozone hole over the president’s head in Kennebunkport.”

With that the media were off and running. The New York Times declared that “ozone depletion is an issue of global importance and that the protective layer is being destroyed at a rate even faster than the pessimists had predicted.” The Washington Post predicted 300,000 new cases of skin cancer in the United States annually by the turn of the century. Time magazine ran a cover story a week after Anderson’s news conference stating that the loss “could have horrendous long-term effects on human health, animal and plant life, and just about every other aspect of the delicate web of nature.”

The Bush administration caved in to the publicity and, less than two weeks after Anderson’s press conference, announced that the United States would cease production of CFCs by the end of 1995, four years earlier than had just been agreed upon at the United Nations’ Montreal accord. Lost in the furor was the fact that 40 atmospheric scientists urged caution in response to the announcement. A senior NASA researcher said, “There is no ozone hole over Kennebunkport and I don’t really expect one.” Also unmentioned was the fact that many refrigerators and air conditioners will become obsolete after 1995 as they will not operate with the substitutes being proposed for CFCs. Also blown plastics, many fire-fighting chemicals, and cleaners will disappear. In essence, media hype forced the government into making a premature decision that will have significant economic consequences with, as yet, undetermined benefits. It is all very reminiscent of the Alar case.

Alar, a chemical widely sprayed used on orchards during the 1980s to slow the ripening of apples, had been discontinued by most apple growers when CBS’ “60 Minutes” ran a scare expose on it on February 26, 1989. Against a backdrop of a huge apple emblazoned with a skull and crossbones, host Ed Bradley solemnly warned that Alar was “the most potent carcinogen in our food supply.” The program warned that Alar was especially dangerous to children and is absorbed into the fruit so that even washing or peeling would not lessen the danger.

Again the response was immediate. Actress Meryl Streep began a campaign against Alar. Schools stopped buying apples for their lunch programs, sales plummeted in stores, and apple growers saw their markets disappear overnight. Many went bankrupt. The EPA asked Alar’s manufacturer, the Uniroyal Co., to pull the chemical from the market which it did by June 1989. The damage was done, however, as apple growers lost $120 million in 1989

Was the reaction to Alar justified? It turns out that CBS’ “scientific advisers” concerning Alar were a public relations firm and the National Resources Defense Council, an activist environmental group that had been pushing to have Alar banned for nearly a decade. In a lawsuit brought by apple growers, it was charged that the trio had deliberately misrepresented Alar’s toxicity in order to achieve a ban on the chemical. This was denied but subsequent testing has shown that Alar, or its metabolic break-down product UDMH, was far less toxic than first believed. Doses of Alar and UDMH in laboratory animals at levels 35,000 times greater than the highest estimated daily intake by school children did not produce the expected tumors. Indeed, so much of the chemical had to be administered that the animals often died of an overdose rather than develop tumors.

The EPA continued to insist that Alar was carcinogenic but conceded that the evidence was inadequate to cause its ban. The American Council on Science and Health, in a report titled “Alar: Three Years Later,” concludes that a special interest group, with the help of the media and some members of the scientific community, forced a chemical that improved apples’ quality off the market, caused enormous financial disruption for thousands of farmers, and resulted in the destruction of tons of wholesome food.

What are the lessons to be learned from these two episodes? If nothing else, that the way scientific controversies are debated should be drastically altered. Major environmental subjects, such as ozone depletion, affect us all and must be open to public scrutiny. But it is equally important that decisions with significant economic impacts be grounded in sound scientific data and not hysteria driven by media hype. As a Science editorial stated last year, both the scientific community and press must develop rules of accountability for either to remain credible in the public mind.

Clair Wood, a science instructor at Eastern Maine Technical College, is the NEWS science columnist.


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