Heavy Metal Toxicity Flashcards
Define trace element
elements at very low concentration levels (usually less than a few ppm in water)
Define trace substance
elements or compounds at very low concentration levels
Give two examples of metals that are toxic even in trace amounts
lead and mercury
What are essential elements
trace elements present in a healthy body
Is more the merrier with essential elements?
no, essential elements have optimal concentrations
What happens when you dont have enough essential elements?
deficiency diseases
What happens when you have too much of a essential element?
negative effects……
What is the treatment for lead poisoning?
Chelation therapy (EDTA)
Name 2 sources of lead
– Water systems through industrial (gasoline and battery)
and mining operations
– Water through mineral ores such as PbS
Name 2 biological effects of lead
– Inhibits hemoglobin synthesis (replaces Fe2+)
– Brain and central nervous system dysfunction(replaces Ca2+)
What is the biological role of arsenic?
replace phosphorous in some microorganisms – not fully understood
Name 2 sources of arsenic
– Water through industrial and mining operations
– Water through mineral ores such as FeAsS (arsenopyrite)
Name 3 biological effects of arsenic
– Interferes with cell energy and growth by chelating to thiol
groups in enzymes
– Carcinogenic
– Small amount of inorganic arsenic compounds can be converted into the less toxic organic compounds and excreted
Which is more toxic As(III) or As(V)?
As(III)
Which is more toxic an organic or a inorganic compound containing arsenic?
the iorganic compound
What is the treatement for arsenic poisoning?
chelation therapy (BAL)
What is the biological role of cadmium?
metalloenzymes for photosynthesis
Name 2 sources of cadmium
– Natural mineral ores such as CdS
– Mining, zinc production , Nickel-Cadmium battery
Name 2 biological effects of cadmium
– Reacts similarly to Zn in body, replaces Zn in enzymes
– Kidney, liver and degenerative bone diseases
Can the human body naturally excrete cadmium?
no
How fast do you need to treat cadmium exposure?
within hours
What is the treatment for cadmium poisoning?
chelation therapy (EDTA, DMSA: dimercaptosuccinic acid)
Name 2 biological effects of Mercury
– Elemental vapour Hg(0)(g) and organic volatile like (CH3)2Hg are the most toxic as they are easily absorbed. Accumulate in brain (visual and hearing loss) – “Minimata disease”
– Inorganic Hg less toxic but can concentrate in kidney and prolonged exposure may cause death or paralysis
Name 2 sources of arsenic
– Water through mineral ores such as HgS
– Burning coal and petroleum, chlor-alkali industry
What is the treatment for Mercury poisoning?
chelation therapy (d-penicillamine or 2,3-dimercaptopropanol (also known as British Anti – Lewisite, BAL))
What is the biological role of Nickel?
metalloenzymes both essential and toxic
Name 2 sources of Nickel
– Naturally occurring ores (high abundance)
– Mining and catalysts in industry, batteries, cigarettes
Name a biological effects of Nickel
Displaces zinc in enzymes
What is the treatment for Nickel poisoning?
chelation therapy: EDTA, DMSA, d-penicillamine
Name 2 sources of Tin
– Water through ores and pipes containing tin
– Mining and catalysts in industry
Name a biological effects of Tin
– Displaces Zn2+ in enzymes
– Displaces Ca2+ affecting signal between neurons
What is the treatment for Tin poisoning?
– chelation therapy: EDTA, DMSA, d-penicillamine
Is an organic or an inorganic compound containing tin more toxic?
organic
Name 2 sources of Aluminum
– Naturally occurring ores (high abundance)
– Cosmetics, catalysts , cookware
Name a biological effects of Aluminum
– Displaces Fe3+ disrupting cell energy production
– Linked to Alzheimer’s disease (aggregates formed in brains)
What is the treatment for Aluminum poisoning?
– chelation therapy: EDTA
