mercury in health care. background on mercury mercury is naturally occurring a silvery white liquid,...

MERCURY IN HEALTH CARE

Background on Mercury• Mercury is naturally occurring a silvery

white liquid, volatile heavy metal and produced through degassing of earth’s crust as 25000-125000 tons per year. It readily vaporizes and stays in atmosphere for up to a year. Ultimately settles in Lake Bottom sediments and bioaccumulates through food chain.

Mercury is a toxic metal that occurs naturally in the environment. There are both inorganic forms and organic forms of mercury. Many of the forms of mercury circulate in the environment, moving from land or water to air and back again, and the forms of mercury may change from one to another as they circulate.

Mercury is highly dangerous environmental toxin and responsible for wide range of health related problems to human beings and surroundings. Due to health hazards from mercury, public awareness is picking up to phase out mercury from health care settings.

In the environment, mercury is found in vapour form odourless and colorless,as solute in water oras solid particulate in different chemical forms having differential toxicity. Around 80 percent of the inhaledmercury vapour is absorbedin the blood through the lungs.

Mercury is naturally occurring, highly volatile heavy metal foundin traces n rocks, soils and oceans.It is airborne through volcanic eruptions and forest fires. Anthropogenic emissions from fossil fuels, incinerators, industries, mining and health care waste and pharmaceuticals.Around fifty times more mercuryin health care waste than general waste

Metallic mercury in pure form is harmless than mercuric chloride

(HgCl2 ) and methyl mercury, a deadly poison.Mercury bioaccumulates and reaches human through food chain or water.

Mercury transport and Bioaccumulation

“Studies show that one gram of mercury will contaminate twenty acre of lake enough to cause poisoning fishes.” When mercurial products incinerated, it becomes vapors in air and ultimately settles down in water bodies and foliage then via biomagnifications in the food chain and bioaccumulation,it reaches humans.

Methylmercury bioaccumulates in thetissues of a fish throughout its lifetime.It can build up to high levels in predatorfish at the top of the aquatic food chain -- levels that are tens of thousandsto millions of times above the level found in the surrounding water. Fish with high levels of methylmercurymay be caught and consumed by humans, waterfowl or other wildlife.

Methyl mercury has capability to interfere with the cell division.

It binds to DNA and interferes with copying of chromosomes and synthesis of proteins. It can

cross blood brain and placental fluids, pregnant women and children are

most vulnerable to effect of mercury.

Mercury is a potent neurotoxin even very low level of exposure may cause permanent damage to thehuman central nervous system.Only 0.9 grams of mercury enough to contaminate 25 acre lake rendering fishes contaminated and unsafe to eat. At higher concentrations can damage vital organs such as lungs, liver and kidneys.

It may cause harmful effects to the nervous, digestive, respiratory, immune systems and to the kidneys and causes lung damage. Adverse effects may be tremors, impaired vision and hearing, paralysis, insomnia, emotional instability, developmental deficits during fetal development and attention deficit and developmental delays during childhood.

Beads of mercury can settle into cracks or cling to porous materials like carpet, fabric or wood, making mercury extremely difficult to remove. Spilled mercury can also be tracked on footwear. Inadequate cleaning and disposal may expose already compromised patients and health care staff to potentially dangerous exposures.

Mercury is mainly used for measurement of temperatureand blood pressure as well as for dental amalgams.Waste incineration and crematoriaare main sources of mercury emissions in atmosphere. Restriction and banning of such articles makes mercury free environment.

Common Sources of mercury in health care waste:1.Thermometers2.Sphygmomanometer3.Feeding tubes4.Batteries5.Dental amalgams 6.Laboratory chemicals as zenker’s solution and histological fixatives

Non-medical uses common in medical settings:

•Cleaning solutions with caustic soda or •chlorine that were contaminated with •mercury during the production process •Batteries •Fluorescent lamps and high-intensity lamps •Non-electronic thermostats •Pressure gauges •Some electrical switches used for• lights and appliances

Routes of mercury exposure

As per WHO, sources of mercury found in the human body (microgram/day):

• Air : 0.040• Fish : 2.34• Non- fish food : 0.25• Drinking water : 0.0035• Mercury vapour from dental : 3-17 Amalgams

Mercury from dental amalgamsand in breast milk of fish eating

others can be high. About one-third of the mercury load in sewage systems is due to dental amalgams.

Mercury is disposed through 1.Incineration 2.Regular flushing in sewers3.Regular dumping in municipal waste bins

Thermometers and sphygmomanometers

are the most potential source and largest mercury reservoirs in the health

care settings. The mercury – free alternative a health care

institution can make a tremendous impact in reducing the potential for

mercury exposure to patients, staff and the environment.

Digital thermometers are coming up

in place of mercury based for preventing from mercury exposure.

Aneroid type sphygmomanometers provide accurate pressure

measurements when a proper maintenance protocol is followed.

It is necessary to identify population at risk and to reduce human-generated

releases.

Total global mercury supply

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1000

2000

3000

4000

5000

6000

7000

8000

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Mercury from US & USSR strategicstockpilesHg recovered from decommissionedmercury cell chlor-alkali facilitiesRecycled mercury

Mining & by-product mercury

Maxson: Mercury flows in Europe and the world, 2004

UNEP Mercury Activities• 2003 – Global Mercury Assessment Report

released; Governing Council concludes national/regional/global actions needed to reduce/eliminate mercury releases

• 2004 – UNEP conducts workshops in developing world to raise awareness of issue, assist countries in identifying regional priorities, and promote actions to reduce releases and exposure

Global mercury consumption, 2000 (tonnes)

Small-scale gold & silver mining (650)

Chlor-alkali (797)

Batteries (1081)

Measuring and control

(166)

Lighting (91)

Electrical control & switching

(154)

Other uses (175)

Dental amalgam

(272)

Maxson: Mercury flows in Europe and the world, 2004

What is needed?

• We must have an international plan; coordinating with other countries to effectively reduce global emissions & use

• EPA has increased the priority given to addressing global mercury issues

–

• For example, the EPA Hg Action Plan addresses:–International long-range transport and fate–Mercury as a global commodity–Technology transfer and capacity building

to help reduce global releases and exposures

• ECOS and others have also expressed the need for global study and action

The ongoing UNEP Assessment is evaluating:

•Sources, emissions inventories, long-range transport, chemical transformations, and fate Production & use patterns as a global commodity•Prevention & Control Technologies & Practices, with associated costs & effectiveness Exposures, effects, impacts to humans and ecosystems•Ongoing actions & plans for controlling releases and limiting use and exposures