Rep. Diane Watson Introduces Anti-Amalgam Bill

Stephen Barrett, M.D.
May 12, 2002

In November 2001, U.S.Representative Diane Watson (D-CA] announced that she was introducing a bill intended to stop dentists from using amalgam to fill cavities [1]. She appears to believe that the mercury content of amalgam poses a severe threat to health. There isn’t a shred of scientific evidence supporting this belief.

Amalgam use has been supported by the American Dental Association [2]; the U.S. Public Health Service; the vast majority of dentists; the National Council Against Health Fraud; and Consumers Union, publisher of Consumer Reports magazine [3]. But Watson, who appears to have swallowed anti-amalgam propaganda completely, thinks that a law is needed to protect the American public from science-based beliefs.

Background Information

Representative Watson was elected to the U.S. House of Representatives in a special election on June 5, 2001, with 75% of the vote. The top 20 contributors to her campaign included the American Medical Association ($5,000), the American Academy of Ophthalmology ($2,500) and the American Dental Association ($1,500). [4] Before entering Congress, she had spent several months as the U.S. Ambassador to Federated States of Micronesia and 20 years as a California state senator, representing the 26th Senatorial District, which encompasses a large portion of Los Angeles. Her background includes:

  • Bachelor of Arts degree in Education, University of California, Los Angeles
  • Master of Science Degree in School Psychology from California State University, Los Angeles
  • Attendance at the Kennedy School of Government at Harvard University
  • PhD in Educational Administration from the Claremont Graduate School in 1987
  • Her occupational experience includes working as an elementary school teacher, acting principal, assistant superintendent of child welfare, and school psychologist. She has taught at both Cal State Los Angeles and Long Beach. She taught gifted children in Okinawa and France; directed the Secondary School Allied Health Professions Project at UCLA; and was a health occupations specialist for the California Department of Education.
  • She was named “Legislator of the Year” several times by the State Bar of California, CSULA, the California Trial Lawyers Association, the California National Organization for Women, and the State Council on Developmental Disabilities; and in 1982, she received the “Alumnus of the Year Award” from UCLA.

In 1992, the California state legislature passed a law written by Watson that would require the state dental board to issue a document listing the risks and efficacies of dental materials. In June 2001, in a letter to the Board, Watson explained that her intent was to focus on amalgam so that consumers would know that “silver” fillings contain mercury and that the mercury content poses a hazard. The simple truth of the matter is that although some forms of mercury are toxic, the mercury in amalgam is tightly bound to other chemicals and is safe. The dental board said this clearly in the fact sheet it released in October 2001:

There are differences between dental materials and the individual elements or components that compose these materials. For example, dental amalgam filling material is composed mainly of mercury (43-54%) and varying percentages of silver, tin, and copper (46-57%). . . . Like all materials in our environment, each of these elements by themselves is toxic at some level of concentration if they are taken into the body. When they are mixed together, they react chemically to form a crystalline metal alloy. Small amounts of free mercury may be released from amalgam fillings over time and can be detected in bodily fluids and expired air. The important question is whether any free mercury is present in sufficient levels to pose a health risk. Toxicity of any substance is related to dose, and doses of mercury or any other element that may be released from dental amalgam fillings falls far below the established safe levels as stated in the 1999 US Health and Human Service Toxicological Profile for Mercury Update [5].

The New Bill

Watson’s proposed bill, titled the Mercury in Dental Filling Disclosure and Prohibition Act, would amend the Federal Food, Drug, and Cosmetic Act to “prohibit the introduction of dental amalgam into interstate commerce . . . effective January 1, 2007, if it is a mercury alloy intended for use as a dental amalgam.” As of July 1, 2002, it would would also ban amalgam use in children under 18 years of age, pregnant women, and lactating women, and would require a warning that ” the product contains mercury, which is an acute neurotoxin, and therefore poses health risks. The bill’s second section — a list of 11 “Congressional findings” — would declare that amalgam “is an acute neurotoxin,” “continually emits poisonous vapors,” poses great danger to developing infants, and is opposed by several prestigious medical organizations. Each of these assertions is preposterous.

In announcing her intentions, Watson contributed to a press release that appears to have been written and distributed by the public relations agency for an anti-amalgam organization. The statements in the release, which is posted to an antifluoridation site, are similar to those in the proposed bill [6].

National Council Against Health Fraud president Robert S. Baratz, M.D., D.D.S., Ph.D., has written detailed analyses of both the bill and the press release [7,8]. He notes that Watson doesn’t appear to understand that different forms of mercury have different properties and that the mercury in tooth restorations poses no danger. He also points out that since the FDA doesn’t actually regulate amalgam, the bill might not have any effect even if it were passed. But he warns:

The American scientific community, on which the FDA depends in part for its advice in the FDA regulatory processes, bases its opinions on the scientific process of discovery, validated by experimental evidence. The purpose of this bill seems to mandate the adoption of illegitimate facts upon the scientific community. It would be a grave and dangerous precedent for that to occur. The review and regulation of medical devices and their components should be based on objective scientific fact, not political whimsy [7].

In May 2002, Time magazine’s Web site posted a column by science writer Leon Jaroff urging Watson to modify her views on amalgam fillings. Calling Watson “scientifically unsophisticated,” Jaroff stated that her association with amalgam opponents “can only tarnish what has been an otherwise worthy career” and advised her to get over her “amalgam hang-up” and “learn not to be taken in by quacks.” [9]

For Further Information


  1. Mercury in Dental Filling Disclosure and Prohibition Act, draft, Nov 1, 2001.
  2. ADA Council on Scientific Affairs. Dental amalgam: Update on safety concerns. Journal of the American Dental Association 129:494-501, 1998.
  3. The mercury in your mouth. Consumer Reports 56:316-319, 1991.
  4. Data from Center for Responsive Politics, accessed Nov 11, 2001.
  5. Dental Board of California. Dental materials fact sheet, adopted Oct 17, 2001.
  6. Statement by Congresswoman Diane Watson (D-Los Angeles): Mercury in Dental Filling Disclosure and Prohibition Act. Los Angeles, California, Nov 5, 2001. Accessed on Fluoride Action Network Web site, Nov 9, 2001.
  7. Baratz RS. Analysis of U.S. Representative Diane Watson’s Statement about the “Mercury in Dental Filling Disclosure and Prohibition Act.” Quackwatch Web site, Nov 13, 2001.
  8. Baratz, RS. Analysis of U.S. Representative Diane Watson’s Proposed “Mercury in Dental Filling Disclosure and Prohibition Act.” Quackwatch Web site, Nov 13, 2001.
  9. Jaroff, L. There’s nothing dangerous about ‘silver’ fillings: But some in Congress continue to insist there is., May 8, 2002.

Quackwatch Home Page

This article was revised on May 12, 2002.