Toxic/Mercury Flashcards

1
Q

What is Mercury ?

A

Elemental mercury is a shiny, silver-white metal that is a liquid at room temperature and is traditionally used in thermometers and some electrical switches.

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2
Q

What are the three types of mercury ?

A

Elemental Mercury(Hg0)
Inorganic (mercurous, Hg1+ or mercuric, Hg2+)
Organic (methyl-, ethyl-, or phenylmercury

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3
Q

What are the elemental mercury ?

A

Elemental mercury is liquid at room temperature. It is used in some thermometers, dental
amalgams, fluorescent light bulbs, some electrical switches, mining, and some industrial
processes. It is released into the air when coal and other fossil fuels are burned.

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4
Q

What are the sources of elemental one ?

A
a) Liquid form
• medical and environmental measuring devises
• disc batteries
• fluorescent light bulbs
• dental amalgam
b) Vapour form
• burning fossil fuels
• manufacturing, processing, and mining
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5
Q

Exposure of Mercury ?

A
Exposure Pathways
Respiratory (harmful vapours inhaled)
• easily absorbed into bloodstream
• easily crosses blood-brain barrier
• oxidizes and deposits in nervous system

Placenta
• easily passes through placenta, accumulating in fetus

Skin
• minimally absorbed through intact skin
Gastrointestinal
• minimally absorbed through gut

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6
Q

What are clinical manifestions of mercyry ?

A
Clinical Manifestations
Lungs (acute inhalation)
• pneumonitis
• respiratory failure
Kidney is final target organ
• mercury accumulates as body tries to clear toxin
Significant prolonged or acute exposure
• salivation
• sweating
• mouth ulcers
• Erethism (red palms/soles)
• emotional lability
• memory impairment

People may be exposed when they breathe air containing elemental
mercury vapors. Vapors may be present in such workplaces as dental offices, smelting
operations, and locations where mercury has been spilled or released. In the body, elemental
mercury can be converted to inorganic mercury.

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7
Q

Inorganic mercury

A

are formed when mercury combines with other elements, such
as sulfur or oxygen, to form compounds or salts. Inorganic mercury compounds can occur
naturally in the environment. Inorganic mercury compounds are used in some industrial
processes and in the making of other chemicals. Outside the United States, inorganic mercury
salts have been used in cosmetic skin creams.

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8
Q

How are inorganic exposure ?

A

People may be exposed if they work where inorganic mercury compounds
are used.

disinfectant
• antibacterial
• antiparasitic
• cathartic
• diuretic
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9
Q

Exposure of inorganic ?

A

Sources
• Mercurous chloride (calomel)
• teething powder, cholera

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10
Q

Exposure of inorganic

A
Exposure Pathways
Gastrointestinal
• local irritant
• can be very caustic
• little systemic absorption unless the
protective barrier compromised

Exposure Pathways

Skin
• poor systemic absorption unless
exposed to large amounts

Clinical Manifestations
Caustic nature can break down
skin or mucosa, leading to
• kidney damage
• neurological damage
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11
Q

Clinical manisfestions of inorganic

A
Clinical Manifestations
Prolonged exposure may cause
• peripheral neuropathy
• hypersensitivity reactions
• on skin or in kidney
• - salivation
• - sweating
• - erethism
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12
Q

Pink disease

A
Manifestations:
• - develops in young children
• - an “anguished”
expression,
• and progressive loss of
• speech, hallucinations, and
• delirium.
• - profuse sweating
• - red, peeling skin
• - swollen, clammy, and cold
• hands and feet
• - intense itching
• - hair los
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13
Q

Acrodynia

A

painful extremities

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14
Q

What are the signs and symptoms of pink disease

A
Signs and Symptoms
• Painful hands and feet
• Pink (dusky progression) color to hands
and feet
• that fade at ankles/wrists
• Nose and cheeks have scarlet hue
• Profuse
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15
Q

Oraganic

A

(methyl,
ethyl,phenyl)

Methylmercury
• used as a crop fungicide
• ubiquitous in environment since
microorganisms
• methylate elemental mercury
Sources
Ethylmercury
• thimerosal used as an antiseptic and
vaccine preservative
Phenylmercury
• -fungicide in latex paints
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16
Q

Sources of inoragnic

A
Sources
Ethylmercury
• thimerosal used as an antiseptic and
vaccine preservative
Phenylmercury
• -fungicide in latex paints

Thimerosal (merthiolate)
Sources:
• Vaccine preservative, nasal spray, contact eye
solutions.
Health Effects:
• Exposure to Hg in utero and children may
cause mild to severe mental retardation and
mild to severe motor coordination impairment;

17
Q

Exposure pathways

A
Gastrointestinal
• almost completely absorbed in gut
because of lipid solubility
Nervous System
• easily crosses blood-brain barrier
has affinity for certain nervous system
cells (methyl)
Exposure Pathways
Placenta
• easily crosses placenta, entering fetal
circulation
Breast Milk
• - easily accumulates and transferred in milk
Respiratory
• unstable phenyl-mercury bond can result in
the inhalation of elemental mercury
18
Q

Clinical manifistetion

A
Clinical Manifestations
Neurological signs and symptoms most
prominent
• Weakness
• Paresthesia
• visual and auditory deficits
• Tremor
• coma
Clinical Manifestations
Children and fetuses exceptionally vulnerable
• Seizures
• psychomotor retardation
• visual and auditory impairment
19
Q

Inorganic

A
Congenital
• Developmental delay
• mental
• Physical
Blindness
Deafness
Muscle atrophy
Seizures
20
Q

Acquired

A
occure after bNumbness of extremities
Lack of coordination
• hands
• gait
• speech
Weakness
Sensory loss
• touch
• vision
• hearing
Seizuresirth
21
Q

Solution - Organic mercury

A
Solutions
(Treatment Summary)
• Chelation therapy is the standard
intervention for elemental and
inorganic poisoning (eg. BAL, DMPS,
EDTA, vitamin C)
• However, chelating agents may
increase the CNS organic mercury
concentration.
22
Q

Treatment

A
Treatment Summary)
• Chelating agents increase the mercury
excretion.
• However, there is little evidence to
show that chelation arrests or
decreases the toxic effects of
chronic mercury poisoning.
Solutions
(Treatment Summary)
• Indications for chelation are not well
established.
• However, chelation is often used
empirically in severe acute cases.