Asbestos removal, the biggest environmental cleanup project in U.S. history, has cost an estimated $50 billion over the past 20 years. It has forced schools to lay off teachers, caused owners to abandon buildings and added considerably to the cost of remodeling many houses.

But one thing this colossal investment hasn't done is produce a measurable improvement in the public's health.

A USA TODAY investigation has found incontrovertible scientific evidence that asbestos in buildings creates a cancer risk so low that it barely can be measured. A person who spends a career inside a building rich with asbestos materials is more likely to die of a lightning bolt, a bee sting or a toothpick lodged in the throat than an asbestos-related cancer.

Despite the minimal risk, asbestos continues to be removed from US. buildings at a cost of about $3 billion a year, largely because the risks were overestimated two decades ago and new scientific evidence has never changed the public perception that asbestos in any form is deadly.

The U.S. situation is very different from that in the developing world, where millions of people in mining and manufacturing are exposed to enough asbestos fibers and dust to cause incurable cancer and other diseases.

But in the USA, the amount spent on asbestos removal "makes no sense from a public health standpoint," says Michael Thune, chief epidemiologist at the American Cancer Society "People have a hard time understanding the magnitude of different risks. The risk of getting cancer from asbestos in buildings is so small that eliminating it wouldn't create a measurable blip in the (171,000) lung cancer deaths that occur every year."

Even the fiercest critics of asbestos doubt the wisdom of removing it from buildings.

"I'm sure you expect me to say, 'Take it out!'" says David Egilman, a Brown University doctor who is a critic of the asbestos industry and a frequent expert witness for workers suing asbestos companies. "But that would be lunacy, and I'm not a lunatic. There are far better ways to spend our money."

Adds Tim Flood, an epidemiologist at the Arizona Health Department: "Asbestos abatement is pretty much a fiasco. It's hard to think of a worse investment." Many more lives would be saved, Flood says, if the money were spent on drug prevention, guardrails, sunscreen, medical research "almost anything, really."

Indoor radon will cause 3,000 times as many deaths. Driving will kill 20,000 times more people. Smoking will kill 50,000 times as many.

For each life saved, asbestos removal costs $100 million to $500 million.

Asbestos panic

Asbestos was one of the most common building materials in the USA until the late 1970s, when large numbers of industrial workers who used it developed cancer. A small fiber mined on six continents, asbestos is prized for its ability to add strength and heat resistance to a variety of materials. At its peak in 1973, the United States used 795,000 metric tons of asbestos in roofs, floors, insulation and hundreds of other products. (A metric ton is 2,200 pounds.)

The crusade to remove asbestos results from a failure to make a distinction about when asbestos is dangerous. Asbestos dust has caused tragic rates of cancer in miners and workers who made and installed asbestos products with insufficient precautions. The workers inhaled asbestos fibers, often for years or decades.

But once products with asbestos are installed, so few fibers are released that the air inside even the most asbestos-rich building is indistinguishable from the air outdoors.

Why have Americans spent billions attacking a minor health risk?

The experts say the fear created by the health tragedy that befell asbestos workers - and the multibillion-dollar lawsuits that followed - overwhelmed the scientific evidence.

In the past 30 years, 171,500 workers in the United States have died of asbestos-related cancers, the worst occupational health disaster of the century. An additional 119,000 U.S. deaths are expected before the epidemic winds down in 2025. Unsafe use of asbestos in poorer nations will cause 30,000 cancer deaths per year for the foreseeable future.

In the 1970s and 1980s in court, plaintiffs' lawyers proved companies hid the dangers of asbestos long after they were known.

So far, 40,000 lawsuits have been resolved; 200,000 are pending. The lawsuits forced Johns-Manville Corp., a powerful building materials company, to seek bankruptcy protection in 1982 and turn over 80% of its stock to workers exposed to asbestos. The company has emerged from bankruptcy, but the bankruptcy and cancer epidemic left the public with an exaggerated fear of asbestos.

Linda Rosenstock, director of the National Institute for Occupational Health and Safety, researched the dangers of asbestos early in her career and remains extremely concerned about its unsafe use. But she says even people who should know better lack a sense of proportion about asbestos risks.

"I remember getting panicked calls from other doctors who had been exposed to a burst of asbestos dust while working on a boiler or whatever," she says. "I would tell them, 'Calm down. It's no worse than smoking
a couple of cigarettes.' Those two cigarettes are certainly not good for your health, but you have to keep it in perspective. The dangers of asbestos - like smoking - depend on amount and duration of exposure."

Workers who developed asbestos-related disease often spent years in clouds of asbestos dust, spraying insulation inside ships or weaving fireproof cloth at textile mills. They worked in places that might have a typical asbestos dust level of 10 fibers per cubic centimeter of air - enough to cause 20% of workers exposed for 20 years to develop lung cancer or mesotheliorna, a fatal cancer of the lung's lining. Their exposure was so high that their spouses had elevated cancer rates because of dust carried home on clothing.

But the risk to U.S. workers from asbestos has been reduced dramatically by relatively inexpensive safety techniques, such as improving ventilation, wetting the dust with water and using respirators. The legal limit on asbestos exposure for workers is 0.1 fibers per cubic centimeter of air, and compliance has not been a problem.

The United States used 21,700 metric tons of asbestos in 1996, mostly in water pipes, brake linings and roof coatings. Consumption is expected to continue at that level.

In everyday life, breathing asbestos is unavoidable. Asbestos is a natural mineral released into the air by wind and erosion, as well as from manmade sources such as brake linings.

Once asbestos is installed, it rarely causes problems to a building's users. Only in a few instances - such as a janitor's removal of asbestos insulation - will a worker be exposed to a high level of asbestos for a short time.

Yet asbestos removal continues on a large scale when there is concrete proof of no danger.

The renovation of a post office in Fort Myers, Fla., last year is typical. The old floor was found to obtain asbetos. testing found no asbetos fibers in the post office's air conditioning filter. But the post office did what is now a common and costly practice.

It halted construction and hired a special crew of men dressed in spacesuits to remove the floor. Customers were banned from the building. A counter was set up outdoors to sell stamps and hand out mail. The cleanup added $155,000 to the original renovation cost of $470,000.

EPA's shifting stand

Although asbestos has faded from the front page, its removal continues at roughly the same pace, costing $3 billion to $4 billion a year the past decade, says Olin Jennings, a Columbia, N.J., consultant who has tracked
asbestos-related spending. In addition to the $50 billion spent so far, Jennings predicts $50 billion more will be spent before the cleanup winds down in 20 years.

"It's a steady industry, but it's not as lucrative as it once was because so many people jumped on the bandwagon. It got very competitive in the 1990s," he says.

Epidemiologists - doctors who study risks - are especially frustrated that asbestos spending has continued despite broad agreement among scientists that it's a waste of money The folly is largely the result of a fear of
lawsuits and bad advice from the Environmental Protection Agency in the early days of the asbestos scare, before scientists had enough evidence to judge the risks.

When the death toll to industrial workers from asbestos became clear, the EPA rushed to act. In 1979, the EPA published a book of guidance on asbestos, commonly called the Orange Book for the eye-catching color of its cover. It said the only permanent solution to asbestos in buildings was to take it out.

In 1983, the EPA issued an updated book, the Blue Book, which declared that removal was "always appropriate, never inappropriate."

That policy has been followed, more or less, ever since, despite backtracking by the EPA as scientific evidence accumulated that the dangers were not as great as feared.

In 1985, the EPA published the Purple Book, which emphasized "managing asbestos" rather than removing it.

In 1990, the EPA issued the Green Book, which said asbestos in schools and offices presented a low risk. It noted that improper asbestos removal could increase exposure by stirring up dust unnecessarily,

But the EPA has never made a dramatic announcement or an effort to reverse the multibillion-dollar asbestos removal effort that its early pronouncements sparked.

Congress passed the Asbestos Hazard Emergency Response Act in 1986. It ordered school districts to locate all asbestos in their buildings and create a plan to manage it. It also imposed tight regulations on asbestos removal, raising costs and ensuring that the image of asbestos-rem oval workers in spacesuits would keep fears high.

Jennings estimates that 15% to 33% of spending on asbestos removal has been in schools. New York City schools have spent more than $100 million.

But starting in 1985, a flow of scientific studies began questioning the wisdom of asbestos removal. The studies appeared in the most respected publications, including Science and the New England Journal of Medicine.

Science ignored

In 1991, the American Medical Association's Council on Scientific Affairs reviewed all the studies on the risks of asbestos and expressed frustration that the science was being ignored. "Educational efforts by scientific organizations and government agencies have been met with frustration, and some of their attempts have been abandoned. In the meantime, real hazards to health smoking, improper diet, inadequate exercise,
high-risk recreational activities - are disregarded by many persons while they complain about the evils of industries whose actual hazards to health often are small by comparison."

The AMA said asbestos removal represented a "mismatch between scientific fact and the need for action."

Also in 1991, the Health Effects Institute, in an EPA- financed report ordered by Congress, conducted the most comprehensive study on the risk of asbestos in buildings. The two-volume study found the lifetime risk of cancer for someone who worked in a building containing asbestos was one in 250,000. By comparison, outdoor air in urban areas has enough asbestos fibers to create a one-in-25,000 lifetime risk of cancer. So an office worker is 10 times safer inside a building made with asbestos than outside it.

Last year, a study for the European Commission reviewed the risks and reached a similar conclusion.

"There does not appear to be sufficient risk to the health of general building occupants to justify arbitrarily removing inact asbestos-containing materials which are in a good state of repair," the report said.

But the cold facts of science have been unable to overcome the passion of public fear.

"It's like telling parents that there's a bomb in the basement of your child's school, but there's only a one-in-a-million chance it will go off,', says Malcolm Ross, a retired geologist at the U.S. Geological Service. "They will demand that the bomb be removed, no matter what the cost or likelihood of detonation

Ross says the environment is full of such bombs - environmental risks - and it makes little sense to target a substance of relatively low risk with an unlimited budget.

"I get furious when I read about some school spending a fortune to remove asbestos," say,, Flood, the Arizona Health Department epidemiologist. In a worst-case scenario, asbestos might increase the 19,000 cancer deaths in his state each Year by three.

"By comparison, we have tens of thousands of cases of skin cancer every year and hundreds of deaths, yet we hardly spend a dime telling people to be careful about exPosing themselves to the sun," he says.

Thune, the epidemiologist at the American Cancer Society, says there shouldn't be a rush to blame well-meaning federal regulators.

"It's not an issue of a blundering bureaucracy that doesn't know how to do anything," he says. "It's hard in a complex system to shuffle resources from one compartment to another to get the greatest yield to public health."

Legal reasons

Legal and economic considerations also have made it difficult to change an asbestos policy that doesn't make sense. Insurance companies don't like to insure buildings containing asbestos.

Some state courts have ordered insurance companies to pay for asbestos removal, ruling that the presence of asbestos is a type of property damage covered by the policy, no different from damage caused by a hurricane.

"Property insurers treat any building with asbestos very gingerly," says Sean Moody, chief economist at the Insurance Information Institute, an industry trade group. "The insurers have been burned in the past, so they're very nervous about issuing policies."

Moody says building owners, realizing the presence of asbestos can send the value of their buildings plummeting, sometimes have torched their properties and filed claims.

Banks are careful about financing the purchase or renovation of buildings containing asbestos.

The way the law reads is that if there is an environmental problem, anyone in the chain of title can be held responsible, going back forever. Since the bank is the one with deep pockets, we're the one everyone wants to sue," says Tom Frye, senior vice president of real estate lending at Sun Trust banks in Nashville. "In order to protect ourselves, banks have to make sure that asbestos is taken care of before the loan is made. That could mean containing it or removing it.

"I'm looking out my window now at an old I I-story building that sold for $4.3 million. The new owner spent $900,000 on asbestos abatement and converted it to a hotel. You don't have to be a mathematician to know the building would have been worth $5.2 million without asbestos."

Frye is aware that the danger of asbestos in buildings is minimal. But his job is to protect the bank's liability, not make social policy.

"It's ridiculous what we sometimes have to demand of people," he says. "But that's what responsible bankers do. That's the way of the world."