An introduction to the health effects of metals l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 37

An Introduction To The Health Effects of Metals PowerPoint PPT Presentation


  • 60 Views
  • Uploaded on
  • Presentation posted in: General

An Introduction To The Health Effects of Metals. A Small Dose of ™ Metal. Complex relationship to metals – Nutritionally Important Toxicologically Important Medical Important Chelation. Introduction. Ancient Awareness. Lead - usage began 4000 years ago

Download Presentation

An Introduction To The Health Effects of Metals

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


An Introduction To The Health Effects of Metals

A Small Dose of ™ Metal


Complex relationship to metals –

Nutritionally Important

Toxicologically Important

Medical Important

Chelation

Introduction


Ancient Awareness

  • 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


Historical Awareness

  • 80 of 105 elements in the periodic table are labeled as metals

  • “Mad Hatter” – mercury exposure


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


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?)


Nutritionally Important

Some metals have very important physiological functions

  • Chromium (Cr)

  • Copper (Cu)

  • Iron (Fe)

  • Magnesium (Mg)

  • Manganese (Mn)

  • Selenium (Se)

  • Zinc (Zn)

Cr

Cu

Fe

Mg

Mn

Se

Zn


Chromium (Cr)

  • 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+


Copper (Cu)

  • 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


  • Iron (Fe)

    • 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


    Magnesium (Mg)

    • 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


  • Manganese (Mn)

    • 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


    Selenium (Se)

    • 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


    Zinc (Zn)

    • 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


    Toxic Metals

    • Aluminum (Al)

    • Arsenic (As)

    • Cadmium (Cd)

    • Cobalt (Co)

    • Lead (Pb)

    • Mercury – Inorganic (Hg)

    • Mercury – Organic (Hg-CH3)

    • Nickel (Ni)

    • Tin (Sn)

    Al

    As

    Cd

    Co

    Pb

    Hg

    Hg-CH3

    Ni

    Sn


    Aluminum (Al)

    • 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


    Arsenic (As)

    • 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…


    Beryllium (Be)

    • 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


    Cadmium (Cd)

    • 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


    Cobalt (Co)

    • 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


    Lead (Pb)

    • 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


    Inorganic Mercury (Hg)

    • 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)


    Organic Mercury (Hg-CH3)

    • 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)


    Nickel (Ni)

    • 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


    Tin (Sn)

    • 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


  • Medically Important

    A small group of metals are used to treat disease

    Bi

    • Bismuth (Bi)

    • Fluoride (F)

    • Gallium (Ga)

    • Gold (Au)

    • Lithium (Li)

    • Platinum (Pt)

    F

    Ga

    Au

    Li

    Pt


    Bismuth (Bi)

    • 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


    Fluoride (F)

    • 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


    Gallium (Ga)

    • 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


    Gold (Au)

    • Use – treat rheumatoid arthritis, range of industrial uses

    • Source – mining, medical injection

    • Absorption – poor

    • Toxicity – kidney, skin and mouth lesions

    • Facts – long half-life


    Lithium (Li)

    • 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


    Platinum (Pt)

    • 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


    Chelation

    • 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


    Summary

    We can not live without metals but some require our utmost respect.


    A Small Dose of ™ Metal


    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.


    Authorship Information

    This presentation is supplement to

    “A Small Dose of Toxicology”

    For Additional Information Contact

    Steven G. Gilbert, PhD, DABT

    E-mail: [email protected]

    Web: www.asmalldoseof.org


  • Login