MINAMATA CONVENTION AND ITS IMPLICATION TO DENTISTRY

Nik Mohd Haziq Asyraff Nik Alim (1090051)

Nur Fatin Rusli (1090028)

Objectives:

1. Able to understand the Minamata disease and its history.

2. Know the content of Minamata Convention on mercury.

3. Describe the relationship of Minamata convention on mercury and dentistry.

4. Can relate the implication of Minamata Convention on mercury towards dentistry.

MINAMATA DISEASE

Is a Methylmercury poisoning with neurological symptoms and caused by daily consumption of large quantities of fish and shelfish that were heavily contaminated with toxic in the sea. It is the first epidemic occurred in southern costal area of Yatsushiro including Minamata through 1950s to 1960s.

This diseases is a negative consequence associated with environmental pollution caused by industrial activity. Where little consideration was given to environment and more priority in productivity.

HISTORY OF MINAMATA

Minamata is small town facing the Yatsushiro sea in southern japan. It is abundant fishing resources for the residents.

On spring day 1956, a girl of 5 years old was found to have unusual neurological symptoms. She had convulsion and difficulties in walking and speaking. She was the first documented case of Minamata disease. The clinical symptoms varies depend on exposure level to the chemical.

SIGN AND SYMPTOMS

Severe cases of Minamata disease are characterized by Hunter Russel syndrome that includes sensory disturbance predominantly in distal portions of extremities, cerebellar ataxia, and bilateral concentric constriction of the visual field.

Other neurological sign and symptoms are: 1. Dysarthria 2. Hearing impairment 3. Disturbance of ocular movement 4. Equilibrium disturbance 5. Tremors.

MILD CASES

It has been reported it associated with: 1. Paresthesia 2. Athralgia 3. Myalgia of extremities 4. Disability using fingers 5. Easy stumbling and unsteadiness 6. Cramp 7. Headaches. 8. Failure of memory 9. Insomia.

The company that responsible for the epidemic was the chemical company named, Chisso.

It’s a predominant company with advance technology in japan at that time. Methylmercury was generated as by product in reaction chamber as for manufacturing Acetyldehyde that was synthesize by a hydrolysis of acetylene using mercury as a catalyst.

Acetyldehyde production increase because of high demand during that era.

Methylmercury is discharge into the sea and accumulated in fish and shellfish through absorption.

MINAMATA CONVENTION

Is a global treaty to protect human health and the environment from adverse effects of mercury. It was agreed at fifth session of intergovernmental Negotiating Committee in Geneva, Switzerland 19 January 2013.

Highlights on ban a new mercury mines, phase out of existing one, control measure on air emissions, and the international regulation of the informal sector for artisan and small scale gold mining.

It was open for signature at special meeting in japan in October 11, 2013. 92 countries have signed the treaty to prevent such a tragedy from happening again.

IMPLICATION WITH DENTISTRY

Dental amalgam is a compound containing mercury and therefore is among the products regulated in the treaty.

Under Article 4 paragraph 3 of the treaty: “Each Party shall take measures for the mercury added products listed in Part II of Annex A in accordance with the provisions set out there in.”

Amalgam

Composition:-mercury (50%),-silver (22-32%),

-tin (14%), -other metals

Widely used since more

than 150 years ago

Not aesthetic

Inexpensive

-Strength-Durable

IMPLICATION TO

DENTISTRY

3) Best management techniques for

amalgam waste

1) Phasing down the use of amalgam

4) Prevention of dental

caries

2) Promotingresearch into

newdental materials

1) Phase Down Amalgam Use Over An Appropriate Time Period

An approach advocated by the World Health Organisation (WHO)

Minimizing the use of mercury in fillings by promoting alternatives.

Phase down phase out

Steps to “phase down amalgam use.”Setting national objectives aimed at minimizing

(amalgam) use; Promoting the use of cost-effective and clinically-

effective mercury-free alternatives; Encouraging professional societies and dental schools

to educate and train dental professionals in the use of mercury-free dental restoration; and

Encouraging insurance policies and programs that favor the use of quality alternatives to amalgam.

3) Best Management Of Dental Amalgam Waste

Dental amalgam waste should be recycled

Should not be disposed of in the general waste, infectious waste “yellow bag,” pharmaceutical waste or sharps container

Should not be rinsed down the drain.

Amalgam waste, if kept separate from other waste, can be safely recycled.

The mercury can be extracted from amalgam wastes through a distillation process and can be reused in new products.

Recycling is best practice for amalgam waste management for dental clinics.

2) Promoting Research Into New Dental Materials

Comparison between new dental materials (eg: composite, GIC, RMGIC, Giomer, compomer) and dental amalgam.

New dental material costly

Types of Amalgam Waste• Non-contact amalgam (scrap)

• Contact amalgam

• Amalgam separators- 95% of amalgam waste but also trap other treatment debris

• Chair side traps

• Vacuum pump filters

• Amalgam sludge

• Empty amalgam capsules

Steps for Recycling Amalgam Waste

1. Stock amalgam capsules in a variety of sizes to minimize the amount of amalgam waste generated.

2. Use high velocity evacuation

3. Use personal protective equipment such as gloves, masks, and protective eyewear when handling amalgam waste

4. Store amalgam waste in a covered plastic container with labelling.

5.Arrange for your recycler to collect your amalgam waste on a regular basis.

4) Reduce The Need For Restorative By Prevention Of Oral Disease

Dental caries cavity restoration Prevention to minimize restorative treatment Prevention could be:

Plaque control Diet counselling Fluoride Fissure sealant

References: Alternative to Mercury Product, Global Mercury

Partnership, UNEP. http://www.ada.org/sections/publicResources/pdfs/

topics_amalgamwaste.pdf http://mercurypolicy.org/wp-content/uploads/2013/01/dent

al_news_march_2013.pdf On The Minamata Convention Concerning Mercury –

UNEP Programme, NOVEMBER 2013. Minamata Convention Text And Annexe,

www.mercuryconvention.org

Thank you