Health Effects of Climate Change THE HEALTH EFFECTS OF CLIMATE CHANGE.
An Introduction To The Health Effects of Metals
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Transcript of An Introduction To The Health Effects of Metals
A Small Dose of Metals – 04/13/11
An Introduction To The Health Effects of Metals
A Small Dose of ™ Metal
ENVIRONMENTAL AND OCCUPATIONAL TOXICOLOGY III
(ENVH 516)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Introduction
Complex relationship to metals –
Nutritionally ImportantToxicologically Important
Medical ImportantChelation
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Lead - usage began 4000 years ago Hippocreates – 370 BC noted abdominal
colic in miner Arsenic – therapeutic and a poison (400 BC) “Lead makes the mind give way”. The Greek
Dioscerides 2nd century BC
Ancient Awareness
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
80 of 105 elements in the periodic table are labeled as metals
“Mad Hatter” – mercury exposure
Historical Awareness
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Thoughts on Metals
Redistribution• Naturally occurring – break down of rock• Human – mining, purify, recombine, use• E.g. lead – rise in Greenland ice
Changed form• E.g. inorganic to organic mercury
Occupational exposure Home exposure
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Susceptibility to Metals
Age – young or old? Nutrition (competion with essential
metals) Allergic response (immune system) Form of metal (organic or inorganic) Lifestyle – smoking or alcohol Occupation Home environment (lead paint?)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Chromium (Cr) Copper (Cu) Iron (Fe) Magnesium (Mg) Manganese (Mn) Selenium (Se) Zinc (Zn)
Nutritionally ImportantSome metals have very important physiological functions
CrCuFeMgMnSeZn
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – essential element, associated with insulin, stainless steel, tanning leather
• Source –food supply, inhalation• Recommended daily – 50-200 µg• Absorption – intestine• Toxicity – acute exposure cause kidney
damage, lung cancer• Facts – comes in different oxidized forms
– Cr3+, Cr6+
Chromium (Cr)
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• Use – essential element, widely used• Source – readily available in food• Recommended daily – 1.5-3.0 mg• Absorption – intestine• Toxicity – deficiency – anemia
- excess rare, Wilson’s disease• Facts – excess treated with penicillamine
- can be toxic grazing animals
Copper (Cu)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – oxygen carrying hemoglobin• Source – food• Recommended daily – 10-15 mg• Absorption – intestine• Toxicity – excess causes bloody fesses,
bloody vomit, liver damage• Facts - 3-5 grams in the body
• 67% associated with hemoglobin
Iron (Fe)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – essential nutrient, associated with many enzymes, antacids
• Recommended daily – 280-350 mg• Source – food supply, nuts, cereals,
seafood, meats, drinking water• Absorption – small intestine• Toxicity – deficiency – convulsions
- excess – nervous system• Facts – 20 grams in body
Magnesium (Mg)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – trace element, associated with many enzymes
• Source – food supply, grains, nuts• Recommended daily – 2 to 5 mg• Absorption – intestine poor (5%)• Toxicity – inhalation – respiratory
disease, nervous system, Parkinson’s -like syndrome, psychiatric disorders
• Facts – half-live 37 days
Manganese (Mn)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – essential element, present in most tissue, anticancer, reduces toxicity of metal mercury and cadmium
• Source – food supply, shrimp, meat• Recommended daily – 55-70 µg/day,
not to exceed 200 µg/day• Absorption – intestine• Toxicity – deficiency – heart disorders
- excess – “blind staggers”, neurological effects
Selenium (Se)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – essential element, cofactor with several enzymes, and proteins
• Source – food supply, drinking water• Recommended daily – 12-25 mg• Absorption – intestine• Toxicity – deficiency – impaired
growth, neurological disorders, - inhalation can cause metal fume fever
Zinc (Zn)
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Aluminum (Al) Arsenic (As) Cadmium (Cd) Cobalt (Co) Lead (Pb) Mercury – Inorganic (Hg) Mercury – Organic (Hg-CH3) Nickel (Ni) Tin (Sn)
Toxic Metals
PbCo
AlAsCd
HgHg-CH3
NiSn
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – wide range of consumer products, airplanes to cans
• Source – food, drinking water• Absorption – poor• Toxicity – Dialysis dementia,
possibly neurotoxic• Facts – non-essential, intake 1-10
mg/day
Aluminum (Al)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – pesticide and herbicide• Source – food, drinking water• Absorption – intestine• Toxicity – cancer, heart, liver,
neurological• Facts – exists in different states –
trivalent (most common), pentavalent, arsenic trioxide, organic and inorganic ...etc…
Arsenic (As)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – metal alloy, nuclear power plants• Source – workplace, coal combustion• Absorption – lung, skin• Toxicity – lung, can be delayed and is
progressive, contact dermatitis probable carcinogen
• Facts – discovered in 1828, more that 1250 tons from oil and coal combustion
Beryllium (Be)
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• Use – alloy in metal, paint• Source – shellfish, cigarette smoke, workplace
– welding, paints• Absorption – intestine, lungs• Toxicity – lung, emphysema, kidney, calcium
metabolism, possible lung carcinogen• Facts – “Itai-Itai” is Japanese for “ouch-ouch”
– refers to bone pain related to calcium loss
Cadmium (Cd)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – component of vitamin B12, • Source – alloy in metals, magnets• Recommended daily – none• Absorption – intestine• Toxicity – excessive heart failure,
inhalation – “hard metal” lung disease• Facts – once used a foaming agent in
beer
Cobalt (Co)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – not essential, batteries, old paint and previously gasoline, hobbies
• Source – home, paint, dust, kids-hands to mouth, workplace
• Absorption – intestine (50% kids, 10% adults)• Toxicity – developmental and nervous system• Facts – developing nervous system very
sensitive to low levels of exposure
Lead (Pb)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – consumer products, industry, dental amalgams, switches, thermometers
• Source – mining, environment• Absorption – inhalation, intestine poor• Toxicity – nervous system toxicant, “Mad
Hatters” disease• Facts – liquid silver evaporates at room
temperature, bacteria convert to organic methyl mercury (see next slide)
Inorganic Mercury (Hg)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – limited laboratory use - most common is methyl mercury (Hg-CH3)
• Source – contaminates some fish (e.g. tuna, shark, pike)
• Absorption – intestine very good (90%)• Toxicity – nervous system toxicant, and
developmental toxicant• Facts – bacteria convert inorganic
mercury to methyl mercury then in to food supply (bioaccumulation)
Organic Mercury (Hg-CH3)
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• Use – not essential, metal alloy, stainless steel
• Source – food supply, jewelry, workplace• Absorption – intestine, skin• Toxicity – carcinogen (lung), contact
dermatitis• Facts – discovered in 1751, 200,000
metric tons used yearly
Nickel (Ni)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – inorganic – consumer products- organic – fungicide, bactericides
• Source – food packaging• Absorption – intestine (low inorganic, high
organic)• Toxicity – inorganic - little
- organic – central nervous system• Facts – triethyltin and trimethyltin most toxic
Tin (Sn)
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Bismuth (Bi) Fluoride (F) Gallium (Ga) Gold (Au) Lithium (Li) Platinum (Pt)
Medically Important
A small group of metals are used to treat disease
F
LiPt
GaAu
Bi
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – antacids, diarrhea• Source – mining, consumer products• Absorption – intestine• Toxicity – kidney, chronic use results
in range of effects• Facts – discovered in 1753, used to
treat syphilis and malaria
Bismuth (Bi)
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
• Use – tooth protection• Source – drinking water, food supply• Absorption – intestine• Toxicity – excess causes mottled
teeth enamel (fluorosis)• Facts – common water level 0.5 to 1.5
ppm, 3 ppm effects teeth
Fluoride (F)
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• Use – visualization tool for soft tissues in x-rays
• Source – mining, medical injection• Absorption – very poor• Toxicity – kidney• Facts – liquid at room temperature,
half-life 4 to 5 days
Gallium (Ga)
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• Use – treat rheumatoid arthritis, range of industrial uses
• Source – mining, medical injection• Absorption – poor• Toxicity – kidney, skin and mouth
lesions• Facts – long half-life
Gold (Au)
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• Use – treat psychiatric disorders• Source – food supply, plants & meat• Absorption – intestine• Toxicity – wide range, e.g. tremor,
seizures, slurred speech, cardiovascular, nausea, vomiting
• Facts – daily intake about 2 mg
Lithium (Li)
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• Use – anti-cancer agent (cisplatin), catalytic converters, metal alloy
• Source – mining, road dust• Absorption – poor, as a drug
intravenous administration• Toxicity – neuromuscular, kidney• Facts – inhibits cell division, treat
ovarian & testicular cancer
Platinum (Pt)
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Properties• Metal chelators accelerate the excretion
of metal from the body• Non-specific – can remove essential
metals and elements• Chelate is from the Geek word for claw
Examples• BAL – one of the first, broad action but
potentially toxic• Calcium EDTA – lead• Penicillamine – copper• Desferrioxamine – iron• DMPS – lead, mercury• Number of others
Chelation
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
We can not live without metals but some require
our utmost respect.
Summary
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
A Small Dose of ™ Metal
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Additional Information
Web Sites• Health Canada - Nutrition.
http://www.hc-sc.gc.ca/english/lifestyles/food_nutr.html
• U.S. Agency for Toxic Substance Disease Registry (ATSDR). http://www.atsdr.cdc.gov/
• Dartmouth Toxic Metals Research Program. http://www.dartmouth.edu/~toxmetal/HM.shtml The site has general information on toxic metals.
A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology
Authorship Information
For Additional Information ContactSteven G. Gilbert, PhD, DABT
E-mail: [email protected]: www.asmalldoseof.org
This presentation is supplement to “A Small Dose of Toxicology”