Mercury Poisoning

Mercury

Poisoning

By

Prof. Dr. Gamal Nasser

MD. Clinical Toxicology

Learning Objectives

• By the end of this lectures you are

supposed to:

– Know different types of mercury.

– Have a good idea about the problem of

acute and chronic mercury poisoning.

– Understand the pathophysiologic

mechanisms in mercury poisoning.

– Know how the patient poisoned by

mercury presents clinically.

Learning Objectives

• By the end of this lectures you are

also supposed to:

– Understand the DD of hematemesis.

– Understand how to diagnose acute and

chronic mercury poisoning

– Be able to provide the necessary

therapeutic measures for different cases

of acute and chronic poisoning.

Introduction

Mercury

• Mercury is a natural substance

that occurs in the environment.

• It is mined chiefly as mercury

sulphide.

• Mercury is released into the

atmosphere from the earth’s crust

and oceans, and by human

activities such as burning coal.

• It is converted to 3 primary forms.

Chemical Forms of

Mercury



1 2 3



Elemental Inorganic Organic

(Hg0) (mercurous (methyl-,

, Hg1+ ethyl-, or

or phenyl

mercuric, mercury)

Hg2+)

Methylmercury, an organic mercury

compound released in factory

wastewater

was the cause of Minamata disease

Mercury poisoning



• Mercury poisoning (also known as

hydrargaria or mercurialism) is a

disease caused by exposure to mercury or its

compounds.



• Fish often contain the largest amounts of

mercury because fish absorb mercury in the

water through their gills, and then predatory

fish that eat other fish are exposed to higher

levels of mercury.

Mercury poisoning



• Mercury poisoning can result in several

diseases, including:



– Gingivostomatitis

– Pneumonitis and Pulmonary oedema

– Gastrointestinal corrosion and ulceration

– Acrodynia (pink disease),

– Hunter-Russell syndrome, and

– Minamata disease.

Uses of mercury

• Manfacture of:

– Thermometers.

– Paints.

– Explosives.

– Lamps.

– Electric apparatuses.

– Batteries.

• Gold mining and extraction.

Uses of mercury

• Mercurous chloride (calomel) and

mercuric chloride were used formerly

medicinally.

• Dimethyl and diethyl mercury are used in

treating seeds (fungicides).

• Phenylmercuric acetate and

phenylmercuric nitrate were used in

indoor latex paints for their anti-mildew

properties, but were removed in 1990

because of cases of toxicity.

Mercury - Absorption



• Inhalation : 60-80%



• Dermal : 3-15%



• GI Tract : Metallic 150-

200µg/l

Diagnosis of Mercury poisoning



• Urine mercury

– probably the most reliable indicator

– Elevated 24 h urine mercury level confirms the

diagnosis of all forms of mercury except short

chain alkyl mercury.

– normal 100-150µg/l



• Radiology: for elemental

ingestion/aspiration/injection

Diagnosis



• Diagnosis of organic mercury

poisoning differs in that whole-

blood or hair analysis is more

reliable than urinary mercury

levels.

This is a one view, abdominal, upright radiograph in a male patient

who intentionally ingested 8 ounces of elemental mercury.

Notice how the mercury outlines the large intestine from ascending to descending

Treatment of Mercury poisoning



• Remove from source

• Supportive care

– particularly important with inhalation

• DMPS Chelation (2,3-Dimercapto-1-

propanesulphonate)

­ Chelation therapy of choice for mercury

­ For both acute and chronic mercury poisoning

­ For all forms of Hg (inorganic > metallic >> organic)

­ Indications:

­ symptomatic patients

­ blood/urine mercury persistently > 100 - 150g/l

Treatment of acute

Mercury

poisoning









CHELATION

TILL THE URINE

ABC MERCURY LEVEL AFTER CARE

FALLS < 50 UG/24H

Treatment of

Chronic

Mercury

poisoning









Stop further Chelation Maintain

exposure

After care

nutrition

Treatment of acute mercury

poisoning



• ABCDEFF

• Admission criteria:

– Renal failure

– Acute pneumonitis with respiratory

distress

Treatment

(Decontamination)

• Identifying and removing

the source of the mercury is

crucial.

• Decontamination requires

removal of clothes, washing

skin with soap and water,

and flushing the eyes with

saline solution as needed.

Treatment of acute mercury poisoning

“Decontamination”





• Metallic mercury:

– If metallic mercury is seen in

the GIT on the abdominal

radiograph, the appropriate

treatment is:

• Activated charcoal

• Followed by WBI

Treatment of acute mercury poisoning

“Decontamination”



• Inorganic mercury:

– Ingestion of inorganic mercury such as

mercuric chloride should be approached

as the ingestion of any other serious

caustic.

caustic

• GIT upper endoscopy should be

considered before cautious gastric

lavage and WBI are performed.

• Fluid and blood replaced as necessary.

Treatment



• Immediate chelation

therapy is the standard

of care for a patient

showing symptoms of severe

mercury poisoning or the

laboratory evidence of a large

total mercury load.

Representation of Chelaton Molecule

Binding with a Mercury Atom

Chelators

of

Mercury









BAL D-penicillamine DMSA DMPS

Treatment



• Chelation therapy for acute inorganic

mercury poisoning can be done with:

– DMSA,

– 2,3-dimercapto-1-propane-sulfonic acid

(DMPS),

– D-penicillamine (DPCN), or

– Dimercaprol (BAL).



• Only DMSA is FDA-approved for use in

children for treating mercury poisoning.



• However, several studies found no clear

clinical benefit from DMSA treatment for

poisoning due to mercury vapor.

Treatment of acute mercury poisoning

“Chelation therapy”



• Should be initiated

promptly when features of

systemic poisoning

develop regardless of

method of exposure.

• Should begins prior to

confirming the diagnosis.

Chelation therapy

(Metallic mercury)



• Oral DMSA:

– may enhance mercury excretion.

• Penicillamine:

– Although given orally its less effects

and associated with more side effects

“Chelation therapy inorganic

mercury ”



• Dimercaprol (BAL):

– Within minutes after ingestion to reduce renal

toxicity.

– Is the preferred chelating agent for mercury

poisoning not involving methyl mercury because

central neurologic symptoms are exacerbated by

this combination because it may redistribute

mercury to the brain from other tissues.

– Chelation with Bal is appropriate if there is renal

dysfunction or severe toxicity.

– 5 mg/kg IM.

Treatment of acute mercury poisoning

“Chelation therapy inorganic mercury ”



• Oral DMSA:

– Is effective but its absorption may

be delayed by the gastroenteritis

and shock.

Treatment of acute mercury poisoning

“Chelation therapy organic mercury”



• Succimer (Dimercapto

succinic acid):

– Is the agent of choice in short chain alkyl

mercury poisoning.

– Especially if the patient has normal renal

function

– 10 mg/kg orally/8 h for 5 days, then bid

for 14 days.

• Oral DMSA is also preferred.

Chelating agents

For

Mercury poisoning







Dimercaprol

(BAL)







For inorganic

Mercury Renal dysfunction Contraindicatedwith

5 mg/kg Severe toxicity Organicmercury

IM







Succimer

Dimercaptosuccinic Acid

( )









For organic short chain 10 orally mg/kg/8 h

Alkyl mercury









Penicillamine

Chronic mercury

poisoning









chronic inhalation of

vapour, dust

Chronic ingestion

or

Of mercurial

skin contact with

compounds

mercury

compounds









Erythrederma

polyneuropathy

(acrodynea,

Mercurialism

Pink disease)

Chronic mercury

Poisoning

(Mercurialism)









Salivation,

Stomatitis,

Insomnia

Loosening of teeth

Mental depression

Tremors Blue line on the gums

Hallucinations

Anorexia,

Mental deterioration

Diarrhoea

Clinical Features of Mercury

poisoning

• Ingestion of mercuric salts results in:

– Severe GIT irritation.

– Acute tubular necrosis.

– No CNS affection.

• Acrodynia:

– Describes an immune mediated condition that affects

children exposed to mercury.

– Its features include:

• Generalized rash.

• Fever.

• Irritability.

• Splenomegally.

• Hypotonia.

Palm of a patient showing discrete erythematous papules and

papulovesicles.

Note lack of oozing, crusts, or excoriations.

Although there is some increased palmar erythema,

it differs from pink disease of inorganic

mercury poisoning of children by presence of papules and lack of pain.

Arm of a patient showing discrete scattered (shotgun) 1- to 2-mm papules.

Note lack of oozing, crusts, excoriations, or other signs of acute eczema.

Acrodynia

• Acrodynia (also known as "Calomel

disease," "Erythredemic

polyneuropathy," and "Pink disease")

– is a type of mercury poisoning in

children characterized by pain and

pink discoloration of the hands and

feet.

Acrodynia



• acr- “extemity” + odynia-

“pain” =

acrodynia = painful

extrem

Acrodynia

(symptoms and signs)

• Painful hands and feet

• Pink (dusky progression) color to hands and

feet that fade at ankles/wrists

• Nose and cheeks have scarlet hue

• Profuse sweating

• Profuse salivation

• Photophobia

• Hypotonia

• Muscle wasting and loss of deep tendon

reflexes

• Lethargy, apathy, irritability

Mercuric salts

Pink disease

Mercuric salts

Pink disease

Patient with intentional ingestion of mercury from blood pressure instrument.

Note how mercury beads can be seen deposited in lung field

Disposal of Industrial wastes

Diagnosis

• It is not that useful to measure these

levels for suspected cases of elemental or

inorganic poisoning because of mercury's

short half-life in the blood.

• If the exposure is chronic, urine levels

can be obtained; 24-hour collections are

more reliable than spot collections. It is

difficult or impossible to interpret urine

samples of patients undergoing chelation

therapy, as the therapy itself increases

mercury levels in the samples.

Clinical Features of Acute

Mercury Poisoning

• Differential diagnosis:

– Corrosive gastroenteritis:

• Acids.

• Alkalis.

• Iron.

• Arsenic.

• Phosphorus.

– Causes of encephalopathy.

– Causes of tremor.