report targets dentists
on industry to keep toxin from going down drain
By Beth Daley, Globe Staff, 6/5/2002
The common dentist office practice of
flushing old mercury-containing fillings down the drain
makes dentists the single largest discharger of the toxic
metal into the nation's wastewater treatment plants,
according to a national study by a Boston-based public
health group. Most of the mercury is eventually discharged
into bodies of water.
In a time that everyone from
hospitals to coal-burning power plants are taking steps to
reduce emissions of mercury, Health Care Without Harm,
along with other environmental groups, is calling on
dentists to follow suit. US dentists still use about 40
tons a year of mercury to make silver fillings. While the
fillings may be fine for years in people's mouths, the
report sponsors' say, they spend a much longer time in the
environment, where they can break down.
''In the last seven years, hospitals
in Greater Boston have reduced mercury pollution,'' said
Bill Ravanesi, campaign director of Health Care Without
Harm, one of the seven sponsors of the report ''Dentist
The Menace?'' He is calling for dentists to use separation
devices to capture the mercury before it is washed away.
''Everyone is doing their part, but
the dental industry hasn't reduced their pollution at
all,'' Ravanesi said.
Mercury is a naturally occurring
metal, but it can do nerve and brain damage in certain
forms and harm fetuses if pregnant women ingest it. Alice
in Wonderland's ''Mad Hatter'' was based on milliners who
suffered from mental problems after using mercury to
For the past 150 years, dentists have
used an inexpensive and durable amalgam of mercury,
silver, tin, copper, and zinc to fill cavities, with
mercury as the main ingredient. Critics for years have
argued that people with mercury fillings can become ill,
but the scientific community still considers the fillings
safe to use.
Although some dentists still use
mercury-based fillings, the use of white plastic
composites is increasing.
There has been little discussion on
the dangers of washed-away fillings until now. Yesterday,
American Dental Association officials said the fillings
pose little danger to the environment because the alloy
doesn't break down. Officials there said they don't oppose
in-office devices to prevent mercury from going down the
drain, but said it's hardly necessary.
''It's a very stable material,'' said
Dan Meyer, director of science for the American Dental
Association. ''We have an ethical and moral obligation to
do good, and we would never do anything to cause harm to
Still, the report's sponsors, who
include the Mercury Policy Project in Vermont and Clean
Water Action in Boston, say evidence exists that the alloy
does break down, releasing mercury into the environment.
For around $50 a month, the report's author estimates,
dentists could capture and recycle the mercury from old
''It can cost the price of a filling
each month to fix,'' said Michael Bender of the Mercury
Policy Project and author of the report.
New England is now one of the most
aggressive in reducing mercury use. Two years ago, New
Hampshire became the first state in the country to ban the
use of mercury in thermometers. Last summer, Massachusetts
public health officials urged young women and children
under age 12 to stop eating most fish from the state's
lakes and streams. Meanwhile, a first-of-its-kind mercury
law in New Hampshire calls for rules for dentists to trap
In 1985, dentists were about the
sixth-largest user of mercury, behind batteries and
factories that use it to produce chlorine, paint, and
measuring instruments, according to the report. Now, with
mercury in many products outlawed, phased-out, or reduced,
dentists are the third-largest user of mercury, behind the
makers of wiring devices and switches, and chlorine. The
report says dentists use about 44 tons of mercury each
year, most of which is eventually released into the
''To me, it's plain and simple,''
says G. Robert Evans, a dentist with West Newton Dental
Associates. Evans said he gave up using mercury in
fillings close to 20 years ago. ''It's going to accumulate
in the environment if we don't keep it out. So I keep it
Beth Daley can be reached at firstname.lastname@example.org.
This story ran on page A3 of the
Boston Globe on 6/5/2002. © Copyright 2002 Globe