Arsenic and Mercury Arsenic and Mercury PoisoningPoisoning

Joseph CampbellJoseph Campbell

AndAnd

Alicia ElgarAlicia Elgar

ArsenicArsenic

Arsenic is found with other metals in natural Arsenic is found with other metals in natural mineral deposits. mineral deposits.

Forms of arsenic can be organic or inorganic.Forms of arsenic can be organic or inorganic.

The inorganic form has the most toxicity.The inorganic form has the most toxicity.

Many inorganic forms of arsenic come from Many inorganic forms of arsenic come from industrial and agricultural waste.industrial and agricultural waste.

Our discussion will focus on the inorganic Our discussion will focus on the inorganic form of arsenic.form of arsenic.

AbsorptionAbsorption

According to the Centers for Disease Control, an average According to the Centers for Disease Control, an average person in the U.S. consumes 50 mg per day.person in the U.S. consumes 50 mg per day.Absorption of arsenic most commonly occurs through the Absorption of arsenic most commonly occurs through the GI tract, lungs, and skin.GI tract, lungs, and skin.Most of the arsenic we ingest comes from our drinking Most of the arsenic we ingest comes from our drinking water, but many forms of arsenic can also be found in food, water, but many forms of arsenic can also be found in food, and wine.and wine.The Environmental Protection Agency allows 10 parts per The Environmental Protection Agency allows 10 parts per billion in drinking water.billion in drinking water.Arsenic is found in tobacco treated by older pesticides.Arsenic is found in tobacco treated by older pesticides.It is absorbed through the skin by direct contact, industrial It is absorbed through the skin by direct contact, industrial and agricultural workers are most susceptible to this form of and agricultural workers are most susceptible to this form of absorption. absorption.

DistributionDistribution

Most of our organs are susceptible, Most of our organs are susceptible, including barriers such as our skin.including barriers such as our skin.

The cardiovascular system efficiently The cardiovascular system efficiently delivers the toxin to major organsdelivers the toxin to major organs ..

Concentrations in urine can cause bladder Concentrations in urine can cause bladder and kidney damage.and kidney damage.

ActionAction

Kills by allosteric inhibition of essential metabolic enzymes.Kills by allosteric inhibition of essential metabolic enzymes.Targets a number of metabolic processes which affect nearly all organ Targets a number of metabolic processes which affect nearly all organ systems.systems.The toxin reacts with sulfhydrl groups .The toxin reacts with sulfhydrl groups .Pyruvate and Succinate oxidation pathways may be disrupted.Pyruvate and Succinate oxidation pathways may be disrupted.Krebs cycle may be disrupted Krebs cycle may be disrupted depletes ATP stores. depletes ATP stores.Prevents transformation of thiamine into acetyl-coenzyme A and Prevents transformation of thiamine into acetyl-coenzyme A and succinyl succinyl CoA CoA thiamine deficiency. thiamine deficiency.Arsenic anions disrupt oxidative phosphorylation by replacing Arsenic anions disrupt oxidative phosphorylation by replacing phosphoryl with less stable compounds phosphoryl with less stable compounds leads to arsenolysis (cell leads to arsenolysis (cell death).death).Reduction in glutathione and antioxidant enzymes Reduction in glutathione and antioxidant enzymes hepatic membrane hepatic membrane damage. (Chattopadhyay 2002)damage. (Chattopadhyay 2002)

Metabolism Metabolism

Arsenic is changed into a less toxic form by Arsenic is changed into a less toxic form by methylation in the liver .methylation in the liver .

Excretion Excretion

Arsenic is excreted in the urine but is highly Arsenic is excreted in the urine but is highly nephrotoxic.nephrotoxic.

Most arsenic is cleared from our systems Most arsenic is cleared from our systems within a few days if the dose is small.within a few days if the dose is small.

Acute exposure Acute exposure

Diffuse capillary leak (internal bleeding) and cardiomyopathy (heart Diffuse capillary leak (internal bleeding) and cardiomyopathy (heart inflammation) inflammation) shock. shock.Renal failure.Renal failure.Elevates liver enzymes and kills liver cells.Elevates liver enzymes and kills liver cells.Noncarcinogenic effects of the skin may develop several years later Noncarcinogenic effects of the skin may develop several years later after exposure!!after exposure!!Increases the frequency of spontaneous abortions in pregnant women Increases the frequency of spontaneous abortions in pregnant women and congenital defects in offspring.and congenital defects in offspring.Patients are treated with chelating agents Patients are treated with chelating agents arsenic forms a arsenic forms a heterocyclic ring which is less toxic heterocyclic ring which is less toxic excreted in the urine. excreted in the urine.Vitamins C and E have been shown to partially reverse arsenic toxicity. Vitamins C and E have been shown to partially reverse arsenic toxicity. (Santra 2000)(Santra 2000)1000 cases are reported each year, but fatalities are rare.1000 cases are reported each year, but fatalities are rare.Most people exposed to high concentrations suffer from secondary Most people exposed to high concentrations suffer from secondary organ damage.organ damage.

Chronic exposure Chronic exposure

Lung, skin, bladder, kidney, and liver cancer is Lung, skin, bladder, kidney, and liver cancer is often attributed to arsenic.often attributed to arsenic.Long-term ingestion through drinking water Long-term ingestion through drinking water more more pronounced blood vessels outside the heart and pronounced blood vessels outside the heart and brain.brain.May destroy neurons May destroy neurons peripheral neuropathy. peripheral neuropathy.May develop bone marrow depression May develop bone marrow depression inability inability to make blood cells.to make blood cells.Pigment changes and thickening of the skin on the Pigment changes and thickening of the skin on the hands and feet. hands and feet.

MercuryMercury

Mercury is a metal that can be found in both Mercury is a metal that can be found in both organic and inorganic forms.organic and inorganic forms.

Mercury is used in fluorescent light bulbs, Mercury is used in fluorescent light bulbs, some medications, thermometers, drinking some medications, thermometers, drinking water, and many other things.water, and many other things.

Young children are more susceptible to getting Young children are more susceptible to getting mercury poisoning than adults.mercury poisoning than adults.

The vapor form of mercury is the most toxic.The vapor form of mercury is the most toxic.

AbsorptionAbsorption

Most commonly by breathing contaminated Most commonly by breathing contaminated air.air.

Can also be absorbed by drinking water or Can also be absorbed by drinking water or eating contaminated food (usually fish, eating contaminated food (usually fish, especially those that eat other fish).especially those that eat other fish).

There about 2 ppm of mercury in one billion There about 2 ppm of mercury in one billion parts of drinking water.parts of drinking water.

DistributionDistribution

Mercury is distributed to the bloodstream Mercury is distributed to the bloodstream from the lungs, then the blood carries it to the from the lungs, then the blood carries it to the central nervous system.central nervous system.

This is especially harmful to young children, This is especially harmful to young children, because their nervous systems are still because their nervous systems are still developing.developing.

ActionAction

There are no known mechanisms for There are no known mechanisms for mercury.mercury.

MetabolismMetabolism

Mercury is converted to HgCl2 where it Mercury is converted to HgCl2 where it remains in the body for years.remains in the body for years.

ExcretionExcretion

Mercury is excreted from the body through Mercury is excreted from the body through urine and feces. It can take the body several urine and feces. It can take the body several months to excrete it.months to excrete it.

Chelation therapy can also be used to help Chelation therapy can also be used to help get rid of the toxin. This is where a get rid of the toxin. This is where a substance that binds to the mercury is substance that binds to the mercury is injected into the body, for easier removal.injected into the body, for easier removal.

Acute exposure Acute exposure

Can lead to lung damage, vomiting, diarrhea, high Can lead to lung damage, vomiting, diarrhea, high blood pressure, eye and skin irritation.blood pressure, eye and skin irritation.Mercury can cause damage to the body even Mercury can cause damage to the body even before effects are noticed!!before effects are noticed!!Some effects include:Some effects include:

TremorsTremorsShynessShynessIrritabilityIrritabilityInsomniaInsomniaChanges in hearing or visionChanges in hearing or visionDifficulty with memoryDifficulty with memory

Chronic exposure Chronic exposure

A few drops can raise the surrounding air to those of A few drops can raise the surrounding air to those of high contamination!!high contamination!!When mercury is inhaled it can lead toWhen mercury is inhaled it can lead to

Acute necrotizing bronchitisAcute necrotizing bronchitisChemical pneumontisChemical pneumontisDeath due to respiratory failureDeath due to respiratory failure

Damage to the kidneys, lungs, brain.Damage to the kidneys, lungs, brain.Symptoms can be passed from child to fetus through the Symptoms can be passed from child to fetus through the placenta, resulting in birth defects;placenta, resulting in birth defects;

Mental retardationMental retardationBlindness Blindness Seizures Seizures Problems with the nervous and digestive systems Problems with the nervous and digestive systems

ReferencesReferenceshttp://http://www.atsdr.cdc.govwww.atsdr.cdc.gov/cabs/arsenic//cabs/arsenic/http://www.epa.gov/safewater/arsenic/http://www.epa.gov/safewater/arsenic/http://www.emedicine.com/neuro/topic20.htmhttp://www.emedicine.com/neuro/topic20.htmhttp://physchem.ox.ac.uk/msds/AR/arsenic.htmlhttp://physchem.ox.ac.uk/msds/AR/arsenic.htmlChattopadhyay, S ; Chattopadhyay, S ; BhaumikBhaumik, S, S ; ; PurkayasthaPurkayastha, M, M ; ; BasuBasu, S, S ; ; ChaudhuriChaudhuri, AN, AN ; ; DasDas Gupta, S Gupta, S. 2002. Apoptosis and necrosis in developing brain cells due to arsenic . 2002. Apoptosis and necrosis in developing brain cells due to arsenic toxicity and protection with antioxidants. toxicity and protection with antioxidants. Toxicology LettersToxicology Letters. v.136, no.1, p.65-76. . v.136, no.1, p.65-76. Santra, A; Maiti, A; Das, S; Lahiri, S; Charkaborty, SK; Mazumder, DNG. 2000. Santra, A; Maiti, A; Das, S; Lahiri, S; Charkaborty, SK; Mazumder, DNG. 2000. Hepatic damage caused by chronic arsenic toxicity in experimental animals. Hepatic damage caused by chronic arsenic toxicity in experimental animals. Journal of ToxicologyJournal of Toxicology. v.38, no.4, p.395-405.. v.38, no.4, p.395-405.http://www.atsdr.cdc.gov/tfacts46.htmlhttp://www.atsdr.cdc.gov/tfacts46.htmlhttp://www.atsdr.cdc.gov/alerts/970626.htmlhttp://www.atsdr.cdc.gov/alerts/970626.htmlhttp://www.mercuryinschools.uwex.edu/http://www.mercuryinschools.uwex.edu/http://www.fda.gov/cder/fdama/mercury300.htmhttp://www.fda.gov/cder/fdama/mercury300.htmhttp://www.epa.gov/mercury/exposure.htmhttp://www.epa.gov/mercury/exposure.htmhttp://www.vaccinationnews.com/DailyNews/July2001/http://www.vaccinationnews.com/DailyNews/July2001/AutismUniqueMercPoison.htmAutismUniqueMercPoison.htmhttp://www.tuberose.com/Mercury.htmlhttp://www.tuberose.com/Mercury.htmlhttp://en.wikipedia.org/wiki/Mercury_poisoninghttp://en.wikipedia.org/wiki/Mercury_poisoninghttp://enhs.unm.edu/5200/mercury/metabolism.htmlhttp://enhs.unm.edu/5200/mercury/metabolism.html