Navigation Links
Dental chair a possible source of neurotoxic mercury waste
Date:3/26/2008

Mercury is a large component of dental fillings, but it is not believed to pose immediate health risks in that form. When exposed to sulfate-reducing bacteria, however, mercury undergoes a chemical change and becomes methylated, making it a potent, ingestible neurotoxin.

While the major source of neurotoxic mercury comes from coal-fired electric power plants, researchers at the University of Illinois at Chicago and at Urbana-Champaign say mercury entering drain water from dental clinics and offices is also a source.

"We found the highest levels of methyl mercury ever reported in any environmental water sample," said Karl Rockne, associate professor of environmental engineering at UIC and corresponding author of the study that appeared online March 12 in the journal Environmental Science and Technology.

Working with James Drummond, UIC professor of restorative dentistry, Rockne gathered waste water samples in collection tanks generated from both a single-chair dentist's office and a 12-chair dental clinic to check for methyl mercury.

Water collected was allowed to settle. Clear layers above the settled particles were then analyzed for presence of methyl mercury. Fine, slow-settling particles of mercury get into the waste water mostly after dentists use high-speed drills to remove old amalgam fillings. The numerous fine particles the drilling produces provide an ample source of exposed mercury surfaces, making them prime targets for sulfur-reducing bacteria that commonly live in anaerobic conditions and are known to methylate mercury.

"It appears to be produced partially, if not fully in the waste water, and it's being produced very rapidly," said Rockne, adding that it was significant this was happening before the particles were getting into sewers, where sulfur-reducing bacteria thrive.

The finding raised the question whether the culprit bacteria were living in the mouths of dental patients. "We don't have the answer," Rockne said.

Based on their sample studies, the researchers estimate that 2-5 kilograms, or up to 11 pounds, of methyl mercury could be entering the public water supply of the United States each year from dental waste water. While this may not seem like much, methyl mercury is highly toxic in minute amounts.

When in waterways, methyl mercury tends to get biomagnified up the food chain, moving from algae and phytoplankton to fish and, ultimately, to humans.

While surprised by the level of contaminants found in the study, Rockne says follow-up research is necessary -- then, possibly, some basic engineering.

"Amalgam separators are a good first step, but maybe something else is necessary downstream to prevent further methylation and prevent further soluble mercury from getting through the system," he said.

"We have to take more steps to prevent the problem from occurring in the first place," he said. "We're dealing with a pipe -- a control point. As an engineer, I see this as a problem that is tractable -- something we can definitely do something about."


'/>"/>

Contact: Paul Francuch
francuch@uic.edu
312-996-3457
University of Illinois at Chicago
Source:Eurekalert

Related biology news :

1. Small-scale fishing in Mexico rivals industrial fisheries in accidental turtle deaths
2. 12 McGill researchers awarded Canada Research Chairs
3. Motor neuron disease and toxic substances: Possible link?
4. Researchers reveal HIV peptides possible pathway into the cell
5. Study says 2000 tigers possible in Thailand
6. NIH selects LIAI for major study on allergy molecular causes and possible treatments
7. Study reveals a key to blood vessel growth and possible drug target
8. Study reveals possible genetic risk for fetal alcohol disorders
9. Study by Pittsburgh researchers identifies possible vaccine target for chlamydia
10. Possible hepatitis C vaccine
11. Key to using local resources for biomass may include waste
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/22/2016)... , December 22, 2016 SuperCom ... of secure solutions for the e-Government, Public Safety, HealthCare, and Finance ... of SuperCom, has been selected to implement and deploy a community-based ... Northern California , further expanding its presence in ... This ...
(Date:12/16/2016)... 2016   IdentyTechSolutions America LLC , a ... solutions and a cutting-edge manufacturer of software and ... offering seamless, integrated solutions that comprise IDT biometric ... solutions provide IdentyTech,s customers with combined physical identification ... crime and theft. "We are proud ...
(Date:12/15/2016)...   WaferGen Bio-systems, Inc. (NASDAQ: ... today that on December 13, 2016, it received a ... Stock Market LLC which acknowledged that, as of December ... stock had been at $1.00 or greater for ten ... Listing Rule 5550(a)(2) of the Nasdaq Stock Market. ...
Breaking Biology News(10 mins):
(Date:1/11/2017)... California (PRWEB) , ... January 11, 2017 , ... ... to support fertility specialists with accurate and reliable preimplantation genetic screening (PGS). , ... have achieved excellent results,” says Ovation Fertility Genetics Scientific Director Amy Jones, ...
(Date:1/11/2017)... ... January 11, 2017 , ... ... in clinical settings, it is becoming increasingly clear that the evolution and transmission ... methods, the standard in the study of clinical resistance, has vastly underestimated these ...
(Date:1/11/2017)... (PRWEB) , ... January 11, 2017 , ... Back pain ... Drugs, No Shots and No Surgery for positive back pain relief for WAR members. ... positive results worldwide and could be life changing for millions suffering from chronic back ...
(Date:1/11/2017)... , Jan. 11, 2017 The ... announced that it has partnered with the Bio-Techne ... science research and diagnostics. The partnership was established ... form of receptor for advanced glycation end products ... subject selection for clinical trials in emphysema. Increasing ...
Breaking Biology Technology: