Dentist Recycling And Awareness Training Module
|Description:||Summary: The University of Illinois School of Public Health conducted a study to quantify the total amount of amalgam used in dental offices in the state of Illinois and to estimate the fractions of amalgam waste material generated during dental procedure. A collection system of containers was placed in six dental offices and clinics to collect the material from the in-line trap, and the excess dental amalgam not placed into the oral cavity. The study also estimates the fractions of non-contact, contact, and tooth retained amalgam through an in vitro study.
The basic ingredients of dental amalgam, by weight, are silver (20 - 34%), tin (8 - 15%), copper (1-15%), other metals (0-5%), and mercury (42-52%). The disposal of dental wastewater streams into sewage system from dental offices and clinics are suspected to contribute from 10 to 40 percent of the mercury loading to wastewater facilities. Given stricter mercury discharge standards, the mercury loading from this and other small sources may influence the ability of treatment facilities to meet NPDES permit requirements. Stricter discharges standards reflect the recognition of the serious impacts of mercury discharges on the ecosystem.
This study, along with previous research, resulted in an estimate of the amount of amalgam being used, and the solid waste amount, which can be discarded and eventually reach the environment.
Mercury data for this study was collected by installing amalgam separators at six dental offices within Illinois. The collection system consisted of three containers placed in the participating dental offices in order to collect:
• Material from the in-line trap, contact amalgam
• Excess dental amalgam that is not placed into the oral cavity, the non-contact amalgam
• Amalgam capsules
Dentists in Illinois (6,455) have the potential to generate 947 kg of non-contact mercury per year, which is recyclable; and 144 kg of contact mercury which has the potential to be discarded or discharged into the environment. Applied to dentists throughout the U.S. (123,641), then 18,159 kg of recyclable, non-contact mercury may be generated per year and 2,763 kg of mercury may enter the environment. These measurements are based on survey data from the ADA concerning the number of working days per year, the number of practicing dentists, a 50%, by weight, mercury content in amalgam and the generation estimates from this project
A major finding of this project was the quantification of the amalgam generation rate for non-contact amalgam. The non-contact amalgam waste stream is easily recyclable. It contains a significant amount of uncontaminated amalgam, which has the potential to generate 211 mg of mercury/day/chair and 126 mg of silver /day/chair. These calculations are based on a 50% mercury and 30% silver, by weight, amalgam composition.
The uncontaminated amalgam has the potential to generate 211 mg of mercury/day/chair, and 126 mg of silver/day/chair. These calculations are based on a 50% mercury and 30% silver, by weight, amalgam composition.
The other fraction of the dental waste stream, contact amalgam, contains all the waste particles that are large than 700 micrometers. This waste stream generates 32mg of mercury/day/chair and 19 of silver/day/chair. A comparison can be made between this study and staff previous work, by accounting for the 7 to 1.5, difference in the median estimates of capsules used per day per chair.
Staff developed a continuing education module at the University of Illinois at Chicago School of Dentistry on best recycling practices and awareness of the effect of mercury on the environment.
Below is a list of organizations with individual contacts that are funding this project.
Organizations Receiving Funding
Below is a list of organizations with individual contacts that are receiving funding for this project.
University of Illinois School of Public Health - Primary Contact
College of Dentistry, Division of Biomaterials and Technology
801 South Paulina St
Chicago, Illinois 60612-7212
p: (312) 413-3790
f: (312) 996-3535
Below is a list of associated organizations that are NOT giving or receiving funding for this project.