Putting Into Place the BMPs

for Amalgam WasteFrederick Eichmiller, DDS

VP & Science OfficerDelta Dental of Wisconsin

Amalgam• Material

– A mixture of elemental mercury with powdered silver-tin-copper alloy

– Mercury combines with silver and tin to form stable strong intermetallic compounds

Powder (~50%) Liquid (~50%)Silver 63% Mercury 100%Tin 23%Copper 13%Zinc <1%

Ag3Sn + Hg Ag2Hg3 + Sn7-8 Hg

The Amalgam Revolution

• Early attempts with lead, tin and bismuth

• The “Amalgam War” of 1850• Dentists manufacturing amalgam• G.V. Black formula (1890s)• The first amalgam standard (1920)• Modern alloys (1960s)

96

157

66

020406080

100120140160180

YEAR

NO

. OF

RE

PL

AC

EM

EN

TS

PE

R Y

EA

R (

MIL

LIO

N)

• Lost “most used” status between 1998 & 1999• Utilization in North America is dropping at a

constant rate• Some European are countries eliminating use• Global demand remains fairly constant

Alternatives

Amalgam

• Most cost effective from cost-service standpoint

• Still only “underwater dentistry” material

• Still frequently the Tx of choice in some situations

Human Toxicity

• What kind of Hg is it?• What’s the route of exposure?• What’s the dose?

Mercury: Man’s Deadly Servant

National Geographic October 1972

J. Osborne

Biological Activity

• 70 trace elements in human body • 35 have no biological activity

Mercury has no biological activity

• Carcinogen: no positive human results

• Teratogens: highly positive, numerous systems

J. Osborne

Liquid Mercury

• Very low absorption on skin

• Less than 0.01% absorption

J. Osborne

Liquid Mercury (continued)

• No toxic effect when swallowed– Less than 0.01% absorption

• Miller-Abbott (bowel obstruction) tube breaks 2% to 3%

• Pre-1900s drink a pound of Hg for constipation

• 7 lbs. Hg ingested (1/2 pint) took 10 days to clear

J. Osborne

Liquid Mercury (continued)

• Bizarre forms – Inject subcutaneously,

intramuscular andintravenously

– Cause local inflammation, abscess and gangrene

– Patient does not see doctor for years– Rarely causes severe mercury toxicity

Inorganic Mercury

• HgCl2 mercuric chloride (corrosive sublime) – Chemical catalyst, preservative, treatment for

syphilis • Hg2Cl2 mercurous chloride (calomel)

– Diuretic and laxative, electrodes• HgO mercuric oxide (montroydite)

– Batteries• HgS mercuric sulfate (cinnabar)

– Red tattoo color, native ore of Hg• Hg(ONC)2 mercury fulminate

– Contact detonators

J. Osborne

Organic Mercury

• Alkyl – methyl - food chain, shellfish,– ethyl - preservative

• Aryl– aromatic series– anti-fungal on seeds

• Phenyl– prevent mildew

J. Osborne

Organic Mercury

• Methyl mercury: Very toxic– 90-95% absorbed in gut – half-life 70-90 days– Hg enters waterway– Methylation by

microorganisms– Hg concentrated as it

moves up food chain (tuna, shark, and swordfish)

J. Osborne

Organic Mercury

• Ethyl mercury, preservative– Thimerosal (mercurochrome)– controls microbial growth 0.003-.01%

used in:

J. Osborne

•Soaps•Shaving cream•Hyper allergic cosmetics•Ear flush•Multidose vaccines

•Gamma-globulin shots•Ophthalmic solutions•Shampoos•Nasal sprays

Organic Mercury

• Aryl– Aromatic series

anti-fungal for seeds– Highly toxic – 90-95% absorption

in gut– Widely used in

agriculture

J. Osborne

Mercury Vapor

• 80% absorbed in lung• Significant toxicity when inhaled• Accounts for most occupational and

home exposures• Acute toxicity is rare, but can occur• Large dose causes acute

pneumonitis, renal failure, seizures and neurological dysfunction

J. Osborne

Mercury Vapor

Sun light

→

UV light

←

J. Osborne

Hg Sources

• 50% of the mercury released to the environment comes from human activity

• Of that amount:– 53% is emitted from combustion of fuels for

energy production and– 34% is from the combustion of waste– 13% from all other sources, including

manufacturers and consumers– Dentistry contributes less than one percent

EPA Data

2001 Hg Use in Products

Measuring and Control

Devices28% Dental

14%

Other7%

Electronic Switches

42%

Electric Lighting

9%

EPA Estimates

Common Mercury-Added Products

Hg in Products

• Hg content in common products:– Toothpaste 3.8 ppb– Deodorant 1.35 ppb– Soap 25 ppb– Laundry detergent 2.4 ppb– Kool-Aid 6 ppb– Mountain Dew .158 ppb

Hampton Roads Sanitation District

USGS/ICE CORES

Dental Use of Mercury

• No organic or inorganic mercury is used in dentistry or in dental amalgam

• Restorations in 1999 required approximately 35 tons of elemental Hg in the U.S.

• The use of amalgam and mercury in dentistry continues to drop at a fairly constant rate (58% from 1979-99)

The Dental Hg Trail

Chairside trapsand vacuum filters

(78% efficient)Amalgam

placements and

replacements

6.5 ton Hg29.7 ton Hg

Sewers & POTWs(Publicly 0wned Treatment Plants)

VanDeven JA & McGinnis SL Water, Air, and Soil Pollution (2005) 164: 349–366

The Dental Hg Trail

Sewers & POTWs

6.5 tons Hg

Incinerated biosolids1.0 tons Hg

Grit solids1.6 tons Hg Beneficial use biosolids

3.6 tons Hg

POTW effluent0.3 Tons Hg

Hg emissions0.1 tons

Total BioavailableUp to 0.4 tons Hg

VanDeven JA & McGinnis SL Water, Air, and Soil Pollution (2005) 164: 349–366

So what’s dentistry’s relative contribution?

010

2030

4050

60

Ton

s/Yr

Coal UtilitiesMunicipal

WasteCombustors

IndustrialBoilers

HazardousWaste

Combustors

Chlor-alkaliPlants

Portland Cement

Kilns

GeothermalPower

Dental

Various Cities’ Estimates of Mercury Loads (% of Total System Loads)

Coming From Dental Facilities

13 14 11

76

34

26

9

0

20

40

60

80

Boston Seattle S.F.

Minn/St Paul Cleveland Duluth

Palo Alto

Typical Mercury Influent Loadings to a POTW (Metro

Boston)

Infiltration

33%

Dental Offices

13%

Water Supply

<1%

Corrosion

<1%

Septage

<1%

DITP Recycle

Stream

7%

Residential Sewage

13%

Inflow

11%

Unknown Commercial

20%

Permitted Industries

3%

Why is Mercury an Issue for Municipal Sewer Systems?

• Plant performance and environmental conditions at outfalls closely scrutinized

• Many POTWs are committed to beneficial re-use of biosolids as fertilizer and soil amendment

• Cities operating combined sewers facing new restrictions on storm water flows

Why is Mercury an Issue for Municipal Sewer Systems?

• Fish consumption advisories in 50 states

• Discharge limits are being lowered nationwide

• Mercury “Virtual Elimination Strategies” are gaining attention in NE, Great Lakes, other locations

The Regulatory Process

• EPA’s maximum mercury allowed in surface water is 0.001 µg /L of mercury per liter for states located along the Great Lakes and 0.05 µg /L for other states.

(µg/L = parts per billion) • States may use more stringent limits

than EPA regulations.

Municipal Wastewater Treatment Facilities’ and

Dentistry• Municipal POTWs are receiving more

stringent mercury limits for their discharge– This requires them to begin to look “upstream”

for additional sources of mercury– Dental offices have been identified by many

cities as a significant mercury source to their systems

– NACWA Position: “Pollution prevention efforts targeting sources of mercury should focus on dental offices and medical facilities (hospitals)”

The Unfortunate Facts

• While our overall contribution to bioavailable Hg is very small, our contribution to an individual wastewater treatment facility averages approximately 40%.

• Treatment facilities have a growing problem meeting their stricter discharge requirements.

They have a problem and they need our help!

The Solution to Pollution is Not Dilution

What about Mercury in Amalgam?

• “While we recognize that dental amalgam is a safe material for filling cavities, its waste should be handled properly, recovered and recycled just as we do with other waste products.”

Dr. J. Bramson, Executive Director, ADA

July 2002 Press Release

So what can your office do today?

ADA Recommended Best Management

Practices (“BMPs”) for Dentists

What are the BMPs?

• Use pre-capsulated alloys• Recycle used capsules • Salvage, store and recycle amalgam • Recycle extracted teeth with amalgam

restorations (following disinfection)• Use disposable chair side traps to

retain amalgam; they can be recycled• Install and use amalgam separators

What are the BMPS? (continued)

• Clean or replace screens, traps and filters regularly

• Store amalgam wastes in separate airtight, labeled containers

• Recycle all amalgam wastes through an amalgam recycler (including used capsules)

• Use non oxidizing vacuum line cleaners

BMP Video

Practices to Avoid

• Never use bulk mercury for amalgams• Never pour bulk elemental mercury

waste in the garbage, red bag or down the drain

• Never place amalgam waste of any kind (including extracted teeth with amalgams) in the biohazard (red) bag, the trash or the sharps container

More Practices to Avoid

• Never rinse traps, filters, or screens over or down the drain, or empty into a waste basket

• Never disinfect teeth or any item containing amalgam with any method that uses heat

More Practices to Avoid

• Never decant liquid in which amalgam has been stored down the drain

• Never rinse tools used to place or carve amalgam over the drain

• Never clean spills of elemental mercury with a vacuum cleaner

Proper Use/Maintenance of Existing Traps is an

Important Amalgam Capture Mechanism

ADA Recommended BMPs for Dentists

• Use non oxidizing agents or cleansers when flushing and cleaning dental suction systems

In-Office Separators

• Sedimentation• Filtration• Ion Exchange

Sedimentation

From suction pump To sewer

Scrap

Sedimentation + Filtration

From suction pump To filter

ScrapTo sewerFi

lter

can

iste

r

Sedimentation + Filtration + Ion Exchange

From suction pump To filter

Scrap

To sewerFi

lter

canis

ter

Ion column

The Current ISO Test

• Run a 10 g sample of amalgam powder through the separator with 1 liter of water

• Capture 95% of the total mass of amalgam powder

• Repeat with a system that is full

Separator ResultsName Company Method Cost Empty / Full

Amalgam Collector R&D Services Sed $350 99.9 / 99.9 %

Asdex Avprox, Inc. Filtr $215 99.1 / 99.4 %

BullfroHg DRNA Technologies Sed/Filt $100/mo 99.9 / 99.4 %

Durr 7800 Air Techniques Centrifug $4,000 98.1 / 97.7%

Eco II Metasys Sed $29/mo 98.2 / 97.5 %

Hg 5 Solmetex Sd/Fl/IonExch $500 99.4 / 99.3 %

Hg 10 Solmetex Sd/Fl/IonExch $6,000 99.9 / NT %

MRU DRNA Technologies Sd/Fl/IonExch $150/mo 99.9 / 99.9 %

MSS 2000 Max. Separation Syst. Sed/Filt $3,000 99.7 / 98.9%

Rasch 890-400 AB Dental Trends Sd/Fl/IonExch $2,730 99.9 / 99.9 %

RME 2000 Rebec Sed $1,895 99.7 / 99.7 %

Fan et al. JADA 2002;133:577-589

Separators come in many different shapes and sizes;

one size does not fit all!

Asdex Amalgam Separation System

Mfr Installation Location

Features

American Dental Accessories$229/unit$79/filter

Chairside (recommended)

One unit per chair (recommended)Monthly-quarterly replacement of filters (workload dependent)Dimensions:Diameter = 3”Height = 9”

Solmetex Hg5 UnitMfr Installation

LocationFeatures

Solmetex Hg5$695/unit$150/filter cartridge

Between chair and vacuum pump

Handles up to 10 chairsOperates using combination of physical settling and chemical filtration

Replace filter cartridge every 6 mos (or when full)Hg10 for larger officesDimensions:10” x 13” x 29”

Solmetex Hg5 High Volume Unit

Mfr Installation Location

Features

Solmetex Hg5$695/unit$250/filter cartridge

20% discount available to dental society members

Between chair and vacuum pump

Designed for larger offices/higher wastewater flowsReplace filter cartridge every 6 mos (or when full)Hg10 for larger officesDimensions:18” x 22.5 x 28”

MRUMfr Installation

LocationFeatures

DRNA, Inc.

$1,800/year lease (includes service/replace-ment costs

Between chair and vacuum pump (can be at outlet)

120V AC (to pump treated effluent)Capacity of 6-16 chairs (flow dependent)Utilizes sedimentation, filtration, ion exchangeDimensions:12” x 16” x 24”

R&D Amalgam CollectorMfr Installatio

n LocationFeatures

R&D Services$495/unit (CH9, 12)(can be emptied and reused)

Chairside (CH9 and12)Central location, immediately upstream from vacuum pump (CH18)

Outlet height needs to be calibrated and adjusted to flow rate; decant as neededDaily valve adjustments to remove treated effluentDimensions:6”x6” x 9” (CH9)6”x 6” x 12” (CH12)

Rasch 890Mfr Installation

LocationFeatures

AB Dental Trends$1190/unit$596 per replacement unit

At outlet of vacuum system (wet system) or outlet of air/water separator (if already installed)

1 unit serves 12 chairsCanister replacement 18 months4 l/min flow rateUpgrade canisters available for additional TreatmentDimensions:12.75”x 10.15” x 28.5”

ECOIIMfr Installatio

n Location

Features

Pure Water Systems$160+ $288 annual exchange and recycling

Between chair and vacuum system

1 unit/5 chairsAnnual Container exchangeInternal mercury recycling programUtilizes specific GREEN & CLEAN M2 cleanerDimensions:8.7” x 8.7” x 13.8”

REBEC Systems

Mfr Installation

Location

Features

Rebec (4 units)$1895-2995/unit$395-495/settle tank

Between chair and vacuum system (not designed for chairside installation)

Units sized to handle different # of operatories; typical replacement recommended annually

Guardian Amalgam Collector

Mfr Installation Location

Features

Air Techniques$1,500-$3,225

After vacuum pump (drains by gravity

Replace collection container every 6 monthsDimensions:6.3”x 10.5” x 7.5”

Amalgam Boss

Mfr Installation

Location

Features

Hygenitek

$695

Chairside or central location before vacuum pump

Replace unit annuallySedimentation/ chemical filtration Recycling program includes disposal costs

Dimensions:12” x 20”

Practical Issues for Selection

of Amalgam Separators• Cost• Effectiveness (Short and Long Term)• Maintenance, Reliability• Solids Handling and Disposal• Integrity of Vacuum Systems

Practical Issues for Selection

of Amalgam Separators (contd)• Space and Utility Requirements

• Dental Office/building Constraints• Regulatory Considerations • Ease of Maintenance and

Replacement• Effect on Other Equipment

Typical Amalgam Separator Installation Locations

Amalgam, other waste buildup in air/water separation chamber

Separators Need to Be Maintained to Operate

Effectively…

Who Should Install A Unit?

• Licensed Plumber recommended• Licensed Electrician may be needed

for systems utilizing pumps (depending upon application)

• May be arranged by dental dealer (depending upon local code requirements, and lease requirements)

Space and Utility Requirements

• Physical Dimensions of typical units– Height: 9-28” – Width/diameter:3-12”– Length 8-24”

• Installation locations (relative to existing vacuum pump and air/water separators)

• Electrical Power Requirements: Typically 110V if not utilizing vacuum system)

Dental Office Constraints

• Basement vs. Office level installations

• Access to Centralized plumbing Locations

• Multi-chair installation requirements• Tenant/Landlord Issues

Other State/Local Regulatory Requirements to

Check…• Plumbing Code requirements for

separators• Amalgam Waste Handling

Requirements• Approved Amalgam Separator list for

your state, county or municipality

Amalgam Separator Buyer’s Checklist

1. Number of Operatories?2. Amalgam restorations placed or removed

per day?3. Office operations (No. days/week)?4. Dental practices/types located in your

building? 5. Do you own or lease your space?6. Would lease stipulations affect installation

of a separator?Source: Kevin R. McManus; P.L. Fan, Ph.D. Hanu Batchu, Purchasing, Installing and Operating Dental Amalgam Separators: Practical Issues, JADA

Amalgam Separator Buyer’s Checklist

7. What terms are included for utilities maintenance?

8. Do you operate wet/dry cuspidors?9. Is sufficient space available to the

air/water/separator drain line and sewer line connection?

10.Access to electrical power (voltage)11.Size and material of existing sewer

connection

Amalgam Separator Buyer’s Checklist

12.Do you operate wet or dry vacuum system?

13.Will any warranty be affected by third party installations?

14. Is the vacuum system dedicated to your office?

15.Location of the vacuum system?16.Space available adjacent to vacuum

system (height, length and width)?

Amalgam Separator Buyer’s Checklist

17.Recommended installation location18.Maximum flow rate19.Life-cycle cost†

20.In your group practice, who is responsible for:

• Water/sewage/utilities?• Equipment servicing and maintenance?• Amalgam collection/recycling?

MAXIMIZING VOLUNTARY REDUCTIONS IN DENTAL AMALGAM

MERCURYReduction in Mercury Discharges

EPA # E0000127PI-98765101-0

Environmental Assistance Center

Marie Steinwachs, Director

                                                                           

Frederick Eichmiller, DDSCo-Investigator

Goals

• Determine whether significant reductions in mercury discharges from dental offices could be achieved through voluntary best management practices (BMPs)

• Determine what effect BMPs have on mercury load to wastewater influent, effluent and biosolids

• To assess the level of knowledge and compliance before and after BMP training

Partners

• Funding and support was provided by:– U.S. Environmental Protection Agency – American Dental Association Foundation – Springfield Public Works Department – Greater Springfield Dental Society – The University of Missouri Extension’s

Office of Waste Management (now the Environmental Assistance Center)

Why Springfield?

• Commitment of staff resources from the Springfield Public Works Department and the Greater Springfield Dental Society

• Low existing level of BMP usage and few amalgam separators

• Modern treatment facilities with little storm water loading and good access for sampling

Design

• Influent and effluent samples collected at two treatment facilities using EPA method 1669

• Total mercury determined by EPA method 1631 at Frontier Geosciences lab

• Biosolid analysis done on monthly blended samples using EPA method 245.1

• Pre-BMP sampling on wastewater done for 4 months, biosolid for two years

• Intervention was a 1/2-day training seminar on BMPs followed by mailings and office visits

Intervention

• ½-day course provided on BMPs for dentists and office staff

• Participants received a DVD, wall poster with best management practices, a brochure of other available resources, and articles including:– Dental mercury hygiene recommendations– ADA Guidelines on Amalgam Accumulations in Dental

Office Plumbing– Summary of Recent Study of Dental Amalgam in

Wastewater– Missouri Dept. of Natural Resources determination of

status and options for various types of dental waste – List of amalgam recyclers

Questionnaire

• A questionnaire was distributed to dentists by the Greater Springfield Dental Society and Environmental Assistance Center in February 2006– Collected baseline data on amalgam use and

management practices. The questionnaire was a list of 34 questions adapted from a national survey of dental office practices conducted by the ADA.

• A follow up survey was distributed to members of the Greater Springfield Dental Society (GSDS) in February 2007 to measure any changes in management practices after the education efforts as reported by area dentists.

Biosolid ResultsDried biosolid levels

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Jan-05 May-05 Sep-05 Jan-06 May-06 Sep-06 Jan-07

Time

mg

/kg

so

lid

No significant difference in biosolid levels after the April 2006 BMP training

Influent Results

Index

NW

Influent

mg/day

272421181512963

4000

3000

2000

1000

0

NW Influent (mg/ day)Intervention took effect after May 2, 2006

Springfield, MissouriSamples drawn every 2 weeks (2-7-06 to 3-27-07)

Intervention

No significant change after BMP training for NW plant with 3 dental offices

Influent Results

Highly significant reduction in loading to SW plant with approximately 90 dental offices

Index

SW

Influent

mg/day

272421181512963

12000

10000

8000

6000

4000

2000

0

SW Influent (mg/ day)Intervention took effect after May 2, 2006

Springfield, MissouriSamples drawn every 2 weeks (2-7-06 to 3-27-07)

Intervention

Effluent Results

No significant change in effluent loading after BMP training for either treatment plant

Index

SW

Eff

luent

mg/day

272421181512963

225

200

175

150

125

100

75

50

SW Effluent (mg/ day)Intervention took effect after May 2, 2006

Springfield, MissouriSamples drawn every 2 weeks (2-7-06 to 3-27-07)

Intervention

Survey Results

• 35% of respondents (25) reported that they did not use dental amalgam.

• Dental amalgam use decreased 5% from the year before.

• A significant decrease (from 70% to 30% ) in improper disposal of capsules in regular waste was observed

• 16% increase in recycling of non-contact scrap, 41% increase in recycling of contact scrap

• 10% increase in the practice of placing non-contact scrap into medical waste containers, and nearly an 18% reported increase in placing contact scrap in medical waste

Traps and Filters

• 23% decrease in the practice of disposing of chairside trap contents with regular waste (42% to 19%)

• 21% increase in the recycling of trap contents (from 29% to 50%)

• A decreases (from 39% to 21%) in the practice of placing filter contents in with regular office waste

• Most of the respondents, 85% (up 20% from the year before) reported using vacuum pump filters

• An increase (41%, up from 23%) in pump filter users who reported placing filter contents in a container with medical waste

Conclusions

• The practice of BMPs in the area dental offices resulted in a measurable and significant reduction in mercury load to the influent wastewater of the treatment plants.

• The practice of BMPs in the dental offices did not result in a measurable change in biosolid mercury levels.

• The practice of BMPs in dental offices did not result in a measurable change in mercury load to effluent treatment water.

• Better training needs to be provided to prevent amalgam waste from being mixed with medical waste for disposal

Line Cleaners

• The following did not appear to mobilize Hg from amalgam particulate:

• All-In-One• E-Vac• Evacuation Cleaner• EZ-Zyme• Gobble Plus• Green and Clean• MAXI-EVAC• ProE-Vac

• Purevac• Sani-Treet Plus• Stay-Clean• Super-Dent• Turbo Vac Line

Flush• VacuCleanse• VAC-U-EZSource: Naval Dental Research Institute

ADA’s Amalgam Waste Program

• Label gray/silver container “Amalgam Waste for Recycling”

• Store amalgam dry (not under fixer or other solutions)

• Utilize USPS or parcel delivery service to ship container to qualified recycler

• Keep written records of the date of the shipment, the approximate mass of waste being shipped, and the name and address of the recycler

ADA Amalgam in Plumbing Waste Initiative

• ADA has prepared “Guidelines on Amalgam Accumulations in Dental Office Plumbing”

• Includes guidance on new office design features Pipe sample taken from

MA dental office 2/03

ADA Guidelines are intended to apply to the following

circumstances:• When plumbing work is being done in areas

where waste may be likely to adhere;• When plumbing work is being done near areas

where waste may accumulate and waste may be dislodged;

• During major operatory renovations;• During demolition work; • Whenever the pipes are cleaned out or a dentist

monitors adhered waste at the request of third parties.

ADA Amalgam in Plumbing Guidelines (New Offices)

• Use of some basic design guidelines can help minimize collection and buildup of amalgam in office plumbing

Today, Dentists Have Better Information and More

Choices• These BMPs will help

ensure that dental offices properly handle and dispose of these wastes

• The options and support for collecting and recycling amalgam waste have increased significantly over past few years

And if All Else Fails…

http://www.ada.org/prof/resources/topics/amalgam.asp

Thank you!