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Ralph Nader > In the Public Interest > Problems with the Detection of Hazards

With all the scientists, modern detection instruments and obligations by corporations and their friendly gov­ernment agencies to find out, it is remarkable how long simple measurements of widespread hazards take to make.

It took a graduate student in the early Seventies to discover mercury contamination in fish from the Great Lakes. It took a chance discovery of radon levels on a Pennsylvania worker in the Eighties to open up the area of radon gas contaminating millions of homes from natural underground sources. And it took a state biolo­gist in 1989 to discover very high radiation levels in wastewater from oil fields which in turn came from naturally occurring radioactive elements brought to the surface during oil drilling.

Why these findings were not made many years ago, given how easy is their first detection, points to lots of people with lots of equipment simply not doing their job. The polluting chemical companies and fishing firms in the Great Lakes area could easily have found out long before a lone graduate student did. Construction firms. environmental and public health agencies could have detected the radon gas in the various regions of the U.S. And the giant oil companies and Occupational Safety and Health Agencies could have learned about this serious radiation hazard to oil field workers.


It is natural for people to ask: “Well, what’s next by way of overdue surprises?” Try “silver fillings, composed of an amalgam half of which is mercury (a toxic heavy metal) that reside in the mouths of hundreds of millions of people. Mercury amalgam fillings have been used for 150 years. Until 1979, research to the contrary ended the American Dental Association’s (ADA) position that mercury does not leach during -cleaning, brushing or chewing.

As a result the controversy has now shifted to whether the mercury that does escape is of a sufficient amount to damage internal organs and the brain. The ADA says no. But this official position of the dental profession is being challenged from two directions in recent weeks. The first challenge comes from University of Calgary researchers who placed 12 mercury amalgam fillings in the-mouths of six sheep. Eight weeks later, unlike the control animals, the test sheep experienced a loss of kidney function ranging between 16 percent and 80 percent A later test involved monkeys and found the mercury in kidneys, digestive tracts and jaws.

The other assault on the ADA’s position comes from 40 dentists who filed a law suit in Cleveland last October alleging that the ADA had breached its contract with them to provide accurate data on mercury amalgams (among other allegations) and has curbed -their professional freedom by making removal of such dental amalgams just to take away the mercury an unethical practice.

Overseas, the German government may move to ban mercury amalgams sometime next year, according to a CBS 60 Minutes report. And the Swedish government has ruled that removals of these amalgams can be reimbursed under the nation’s health insurance system.


The ADA is in a tough spot. After assuring millions of people that mercury amalgams were and are perfectly safe, and not wanting to give unscrupulous dentists a major business opportunity in removing such fillings, the Association is finding it difficult even recognizing the possibility of a problem In short, it is finding itself unable to perform science – what Alfred North Whitehead called, “keeping options for revision.*

There are alternative dental fillings available including gold, composite resins and porcelain. Gold is, of course. very expensive, but the most safely inert metal. Plastics and porcelain, though widely used, have their functional detractors for large cavities.

I asked several dentists in Washington what they thought of this latest “mercury alarm.” They all said that more intensive research by private and public agencies is in order. Then they gave a reply I had not heard before. They said that they have been working with mercury – silver amalgam for many years in their office and also have such fillings in their own mouths. Yet their regular tests for mercury in their bodies show levels well under the standard that is considered safe.

So there you have it to this point. A controversy that should have been resolved decades ago will increase in intensity during the Nineties before it is ‘resolved as a matter of dental practice.

If you want the opinion of the Food and Drug Administration, drop them a line in Washington, D.C.