Dentists to post cancer warnings
Advisory will warn patients of exposure to mercury, other chemicals
By Suzanne Bohan, STAFF WRITER
 

A new warning sign will show up in dentists' offices statewide in early 2003, letting patients know their visit may entail exposure to mercury and cancer-causing chemicals.

Health advocates say the move puts California in the lead of a small but growing nationwide trend of warning patients about the mercury contained in amalgam fillings. Both New Hampshire and Maine now have laws requiring consumer notification and education about the mercury in dental amalgams, and similar legislation was recently introduced in Massachusetts, according to Michael Bender, director of the Mercury Project.

The California Dental Association agreed to require its members to post the warning to settle a lawsuit brought against the association by As You Sow, a San Francisco environmental group. On Monday, representatives from the two groups and the state Attorney General's office will meet in San Francisco Superior Court for what all parties expect will be final approval of the settlement.

An estimated 12,000 dentists in the state don't belong to the dental association, and thus won't be required to post the sign, but many are also expected to join the settlement. Those joining the settlement are protected from patient lawsuits over any of the substances listed in the agreement, said Jim Dufour, the attorney representing the dental association.

The environmental group filed suit in 2001 under California's Proposition 65, an initiative approved by voters in 1986 that requires businesses and employers to post warnings if their activities may expose customers or employees to chemicals -- or in the case of mercury, a metal -- that are known to harm health. Cur- rently, Prop. 65 warning signs for a range of toxic substances are found in venues as diverse as bars, gas stations and factories.

The settlement between the dental association and As You Sow calls for the 18,000 dentists belonging to the association, as well as dental schools, to mount a sign that notifies patients that dental amalgam contains mercury. Part of the message will state that mercury is known "to cause birth defects or other reproductive harm," according to Shawn Khorrami, the Van Nuys attorney representing As You Sow. It also will warn that chemicals known to cause cancer -- specifically chloroform and methylene chloride -- are in sealants used in root canal, fillings, bridges and crown treatments.

While Dufour said the lawsuit "was quite amicably resolved," both sides remain deeply divided over the meaning of the warning.

As the dental association sees it, the warning simply provides consumers with information about a potential risk, since Prop. 65 requires a warning when people will be exposed to one-one-thousandth of the exposure known to cause harm.

"The state law requires a warning to customers at a very, very low level of exposure to make informed decisions," Dufour said. "Prop 65 is not about a health risk. It's a consumers' rights law."

Even though the association agreed to post the warning, the group still believes dental amalgams are safe, said Lori Reed, a spokeswoman for the group.

"Even though the amalgams contains mercury, there is no scientific evidence that mercury (in them) causes serious illness," she said, adding that her group relies on guidance from federal health agencies regarding the safety of amalgams. The Food and Drug Administration, which regulates dental amalgams, states that the mercury in the compound poses no health risk.

But Ed Weil, the deputy state attorney general handling the case, views the purpose of the notice differently. "We regard the warnings as health warnings. I know the dental people don't regard it that way.

"It's a health warning, but there are degrees of all of this," he added. "The purpose of Prop 65 is to give people information and let them make their own choices. The idea is instead of (the state) deciding what you should and shouldn't know, we're going to give you the information and let you decide."

Khorrami, on the other hand, is unequivocal that the mercury contained in dental amalgams -- which also contain silver, tin and copper -- poses a significant risk. Amalgam filling emits mercury vapors, particularly when exposed to hot foods or liquid, pressure like chewing, or abrasion from toothbrushes, according to Boyd Haley, the chair of the chemistry department at the University of Kentucky, and one of the nation's leading scientists opposed to the use of mercury in dental practice.

"It's constantly emitted, so there's chronic exposure," said Khorrami.

Haley said that the mercury vapors can cause neurological harm, as the heavy metal interferes with the function of proteins. "In the case of neurons, it disrupts the nerve action," he said.

While the new ruling will only apply to dentists who belong to the association and who have 10 or more employees, many members of the group with fewer than 10 employees are also expected to post the signs as they become available over the two to three months.

Contact Suzanne Bohan at sbohan@angnewspapers.com .