The cause of little Mallory's tumor. he suggested to Michelle, might well be the electromagnetic fields (EMF) emanating from the nearby transmission lines of San Diego Gas & Electric. He told her about Michael Whitney, a Seattle lawyer who had handled previous EMF cases. A year later Michelle and her husband Ted filed a lawsuit against SDG&E alleging that EMF was the cause of Mallory's cancer.

EMF seemed to be a tort lawyer's dream. Withey saw the potential for a mass tort blitz. If hundreds of thousands of frightened clients across the country could be persuaded to file lawsuits, scientific evidence would become almost irrelevant. The prospect of simultaneously defending themselves from thousands of lawsuits would force power companies to reach a settlement. The same tactic had worked against other industries; the asbestos onslaught a decade earlier had produced more than 200,000 lawsuits.

A front page story in The Wall Street Journal quoted Withey as boasting that the case of little Mallory was a "slam dunk." He predicted it would trigger an avalanche of claims, and most legal experts agreed. "Public concern over EMF is rising irrespective of its validity," a cover story in the ABA Journal, the organ of the American Bar Association, coolly observed. It was now a race between science and the fearmongers.

The scientific community began to speak up. Most scientists were highly skeptical of the purported EMF-cancer connection. The effect of all known cancer-inducing agents--ionizing radiation such as X rays, chemical carcinogens, such as tobacco smoke, and certain viruses--is to break the chemical bonds that make up DNA, creating mutations. But to break bonds you need very high frequency waves, and EMF fields that cycle 60 times a second don't have anywhere near enough energy. Besides this theoretical consideration, there is the epidemiological fact that life expectancy has almost doubled in the past hundred years, most of the increase coming since the advent of electricity.

In a series of sequels for The New Yorker, Brodeur relied on selected anecdotes to create a menacing atmosphere of silent invisible fields invading homes and schools-and a conspiracy to hide the truth from the public. He went into great detail about all the health problems suffered by folks living on Meadow Street in Guilford, Conn. They were coming down with everything from brain cancer to Osgood's knee-and there was an electric substation on Meadow Street.

Such anecdotes have a powerful emotional impact. For every Meadow Street, however, there may be a Forest Street, also with a substation, where no one seems to get sick. But Brodeur wasn't interested in Forest Street. His focus on cancer-clusters is called "The Texas Sharpshooter Fallacy" by statisticians: You empty your revolver into the side of a barn, then walk over and draw a bullseye around each hole. Anecdotal evidence surrounds us-in newspaper headlines, in gossip among neighbors, in the courtroom. It doesn't carry much weight with statisticians. If you are going to argue from statistics, they will tell you, you must use all of the statistics. Few of us are statisticians, however, and the story of Meadow Street was convincing to many New Yorker readers.

Concern over power-line fields started in 1979 with the report of a Denver epidemiologist that children from homes with "high" magnetic fields from power lines were three times as likely to develop leukemia as children from homes with "low" fields. But the study was not blind, that is, the epidemiologist knew in advance which were the homes of the leukemia victims. Consciously, or unconsciously, researchers testing a daring hypothesis like this want it to be true, and that bias can distort the data. For that reason careful scientists in such a test arrange to have the purported cause (in this case, electromagnetic field strength) measured by testers who don't know anything about the purported result (cancer incidence).

The Denver study, moreover, did not try to establish a "dose-response relationship," because it did not measure the relative strengths of the power-line fields. It merely estimated them based on the size and proximity of the power-lines. Childhood leukemia is a rare disease, and a reclassification of only a few victim's homes from "high-field" to low-field" would be sufficient enough to change the conclusion.

Nevertheless, the report triggered the usual rash of "confirmations." There were reports that electrical workers suffered high cancer rates. Women using electric blankets or working at computer terminals were said to suffer frequent miscarriages. Suicides were supposed to be occurring at an alarming rate among people under power lines. Farmers complained that the proximity of power lines made their cows stop giving milk and their chickens stop laying eggs. Although none of these stories were backed up by reliable statistical evidence, each new anecdote reported in the media added to the panic.

But as results began to come in from larger and more sophisticated studies in which the fields were carefully measured, the EMF-cancer connection grew weaker. Paul Brodeur was not there in 1996 when the National Academy of Sciences released the results of an exhaustive three-year review of possible health effects from exposure to residential electromagnetic fields. That year he left the staff of The New Yorker.

The large conference room in the Academy building on Constitution Avenue in Washington was crowded with reporters, TV cameras, and a few scientists. The head of the review panel, Charles Stevens, a distinguished neurobiologist with the Salk Institute, summed up the results: "Our committee evaluated over 500 studies, and in the end all we can say is that the evidence doesn't point to these fields as being a health risk."

There were reporters in the room who had been writing stories about the dangers of power-line fields for years. For Louis Slesin, the editor of Microwave News, an influential newsletter devoted entirely to the EMF health issue, the controversy was his livelihood. For these reporters to now write that it had all been a false alarm would have been miraculous. They would scour the report looking for soft spots. But the evidence against a connection between electricity and cancer was getting harder to ignore.

The following year the National Cancer Institute released an exhaustive seven-year epidemiological study of EMF and childhood leukemia, the disease that started it all. As is so often the case with voodoo science, the effect had gotten smaller with each improved study. Now, after 18 years, it was gone completely. Similar studies in Canada and Britain have since reached the same conclusion.

Of the multitude of problems that daily vex society, few can sensibly be resolved without recourse to the knowledge of science. But society cannot always wait for the scientists. Courts must resolve disputes, laws must be enacted, regulations imposed, all on the basis of the best scientific information available.

Preposterous claims are no great threat to science. They are merely background noise, annoying, but rarely rising to a level that seriously interferes with genuine scientific discourse. The real threat is to the public, which is not in a position to judge which claims are real and which are voodoo.

All too often the media come down on the side of voodoo and against science. It is an understandable, if inexcusable, bias. Paul Brodeur would have had a hard time making a bestseller out of a book entitled Innocuous Currents.

The EMF controversy has faded from view, but think of the damage done in the meantime. Hundreds of millions of dollars were spent in litigation between electric utilities and tort lawyers. Homeowners near power lines saw a collapse in property values. Municipalities had to pay for new electrical work in schools. The real cost though is human. Millions of parents were terrified to no purpose.

The Zuidermas lost their case claiming that electricity sickened Mallory.

Have the journalists who propagated this senseless scare recanted? Scarcely. Louis Slesin still publishes Microwave News. Paul Brodeur never admitted that his book was fundamentally wrong. He says he doesn't write about public health matters these days... he' turned to fiction.

This excerpt is adapted from Voodoo Science, by Robert L. Park.