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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)
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology Introduction Complex relationship to metals – Nutritionally Important Toxicologically Important Medical Important Chelation
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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
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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
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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
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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?)
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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 Important Some metals have very important physiological functions Cr Cu Fe Mg Mn Se Zn
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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 – Cr 3+, Cr 6+ Chromium (Cr)
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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)
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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)
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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)
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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)
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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)
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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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology Aluminum (Al) Arsenic (As) Cadmium (Cd) Cobalt (Co) Lead (Pb) Mercury – Inorganic (Hg) Mercury – Organic (Hg-CH 3 ) Nickel (Ni) Tin (Sn) Toxic Metals Pb Co Al As Cd Hg Hg-CH 3 Ni Sn
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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)
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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)
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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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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)
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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)
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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)
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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)
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology Use – limited laboratory use - most common is methyl mercury (Hg-CH 3 ) 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-CH 3 )
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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)
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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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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 Li Pt Ga Au Bi
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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)
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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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology 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
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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
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology A Small Dose of ™ Metal
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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.
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A Small Dose of Metals – 04/13/11 A Small Dose of Toxicology Authorship Information For Additional Information Contact Steven G. Gilbert, PhD, DABT E-mail: sgilbert@innd.org Web: www.asmalldoseof.org This presentation is supplement to “A Small Dose of Toxicology”
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