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Topic:
Metals uptake by
organisms
By
Maryum Atique
M. Phill chemistry
University of
Agricylture, FSD
HEAVY METALS
The term heavy metal refers to any metallic
chemical element that has a relatively high
density and is toxic ...
Properties
• are natural components of the Earth's crust
• they cannot be degraded or destroyed
• to a small extent they e...
Bioaccumulation

• Bioaccumulation is the “build-up of
chemicals or heavy metals in living
organisms”.
• The chemical accu...
Mercury
Hg
• Mercury is the only common metal which
is liquid at ordinary temperatures. It rarely
occurs free in nature an...
•
•
•
•

Health effects of mercury
Disruption of the nervous system
Damage to brain functions
DNA damage and chromosomal d...
• Acidic surface waters can contain significant
amounts of mercury
• When the pH values are between five and
seven, themer...
Cadmium
Cd
Sources of Cadmium
 Cadmium is used as an electrode in
“nicad” batteries
 Cadmium is used as a pigment in
paints(yellow ...
HEALTH EFFECTS

• Human uptake of cadmium takes
place mainly through food
• Diarrhoea, stomach pains and
severe vomiting
•...
Environmental effects of cadmium
• Cadmium can be transported over great
distances when it is absorbed by sludge
and can p...
Chromium - Cr
• Chromium(III) is an essential nutrient for
humans and shortages may cause heart
conditions, disruptions of...
HEALTH EFFECTS
• When it is a compound in leather products, it can
cause allergic reactions, such as skin rash
• After bre...
Environmental effects of chromium
• Most of the chromium in air will eventually settle
and end up in waters or soils
• Chr...
Lead - Pb
• Foods such as fruit, vegetables, meats, grains,
seafood, soft drinks and wine may contain
significant amounts ...
Lead sources
•
•
•
•

application of lead in gasoline
fuel combustion
industrial processes
solid waste combustion
Health effects of lead
• Disruption of the biosynthesis of
haemoglobin and anemia
• A rise in blood pressure
• Kidney dama...
Environmental effects of lead
• Soil functions are disturbed by lead
intervention, especially near highways and
farmlands,...
Arsenic
• Arsenic oxides were the
common poisons used for
murder and suicide from roman
times through to the middle
ages
•...
Sources of Arsenic
 Pesticides
 Mining, smelting of gold, lead, copper
and nickel
 Production of iron and steel
 Combu...
Health effects
 Birth defects
 Carcinogen:
Lung cancer results from the inhalation of
arsenic and probably also from its...
Arsenic in drinking water in
US
General sources of heavy metals in
residential houses
• Infiltration from outside, along with
the dust carried on shoes an...
Methods for measurement of trace
metals

 Most common method of collecting particulate matter is
through filters
 Identi...
Control strategies
Control methods
• Periodic vacuuming of the house can be effective
in removal of these pollutants
• Replacement of wood-bu...
Metal uptake by organisms
Metal uptake by organisms
Metal uptake by organisms
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Metal uptake by organisms

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Metal uptake by organisms

  1. 1. Topic: Metals uptake by organisms By Maryum Atique M. Phill chemistry University of Agricylture, FSD
  2. 2. HEAVY METALS The term heavy metal refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations.
  3. 3. Properties • are natural components of the Earth's crust • they cannot be degraded or destroyed • to a small extent they enter our bodies via food, drinking water and air • as trace elements, some heavy metals (e.g. copper, • selenium, zinc) are essential to maintain the metabolism of the human body • however, at higher concentrations they can lead to poisoning • heavy metal poisoning could result, for instance, from drinking-water contamination (e.g. lead pipes), high ambient air concentrations near emission sources, or intake via the food chain
  4. 4. Bioaccumulation • Bioaccumulation is the “build-up of chemicals or heavy metals in living organisms”. • The chemical accumulates because it does not break down easily (decomposers can’t break them down) • The chemicals get stored in fat-cells of organisms and can cause serious problems...
  5. 5. Mercury Hg • Mercury is the only common metal which is liquid at ordinary temperatures. It rarely occurs free in nature and is found mainly in cinnabar ore (HgS) in Spain and Italy. • It alloys easily with many metals, such as gold, silver, and tin - these alloys are called amalgams. Its ease in amalgamating with gold is used in the recovery of gold from its ores.
  6. 6. • • • • Health effects of mercury Disruption of the nervous system Damage to brain functions DNA damage and chromosomal damage Allergic reactions, resulting in skin rashes, tiredness and headaches
  7. 7. • Acidic surface waters can contain significant amounts of mercury • When the pH values are between five and seven, themercury concentrations in the water will increase due to mobilisation of mercury in the ground • Once mercury has reached surface waters or soils microorganisms can convert it to methyl mercury, a substance that can be absorbed quickly by most organisms and is known to cause nerve damage
  8. 8. Cadmium Cd
  9. 9. Sources of Cadmium  Cadmium is used as an electrode in “nicad” batteries  Cadmium is used as a pigment in paints(yellow color)  It is also used in photovoltaic devices and in TV screens  Cigarette smoke  Fertilizers and pesticides Note: The greatest proportion of our exposure to cadmium comes from our food supply- seafood, organ meats, particularly kidneys, and also from potatoes, rice, and other grains.
  10. 10. HEALTH EFFECTS • Human uptake of cadmium takes place mainly through food • Diarrhoea, stomach pains and severe vomiting • Bone fracture • Damage to the central nervous system • Damage to the immune system • Psychological disorders • Possibly DNA damage or cancer development
  11. 11. Environmental effects of cadmium • Cadmium can be transported over great distances when it is absorbed by sludge and can pollute surface waters as well as soils • Cadmium strongly adsorbs to organic matter in soil • When cadmium is present in soils it can be extremely dangerous, as the uptake through food will increase • Soils that are acidified enhance the cadmium uptake by plants • This is a potential danger to the animals that are dependent upon the plants for survival – Cadmium can accumulate in their bodies, especially when they eat multiple plants. e. g: cow
  12. 12. Chromium - Cr • Chromium(III) is an essential nutrient for humans and shortages may cause heart conditions, disruptions of metabolisms and diabetes • But the uptake of too much chromium(III) can cause health effects as well, for instance skin rashes
  13. 13. HEALTH EFFECTS • When it is a compound in leather products, it can cause allergic reactions, such as skin rash • After breathing it in, chromium(VI) can cause nose irritations and nosebleeds • Upset stomachs and ulcers • Respiratory problems • Weakened immune system • Kidney and liver damage • Alteration of genetic material • Lung cancer • Death
  14. 14. Environmental effects of chromium • Most of the chromium in air will eventually settle and end up in waters or soils • Chromium in soils strongly attaches to soil particles and as a result it will not move towards groundwater • In water chromium will absorb on sediment and become immobile
  15. 15. Lead - Pb • Foods such as fruit, vegetables, meats, grains, seafood, soft drinks and wine may contain significant amounts of lead • Cigarette smoke also contains small amounts of lead
  16. 16. Lead sources • • • • application of lead in gasoline fuel combustion industrial processes solid waste combustion
  17. 17. Health effects of lead • Disruption of the biosynthesis of haemoglobin and anemia • A rise in blood pressure • Kidney damage • Disruption of nervous systems • Brain damage • Diminished learning abilities of children • Behavioural disruptions of children, such as aggression, impulsive behaviour and hyperactivity
  18. 18. Environmental effects of lead • Soil functions are disturbed by lead intervention, especially near highways and farmlands, where extreme concentrations may be present • Also soil organisms are suffered from lead poisoning
  19. 19. Arsenic • Arsenic oxides were the common poisons used for murder and suicide from roman times through to the middle ages • Arsenic compounds were used widely as pesticides before the organic chemicals era • Arsenic is very much similar to phosphorous
  20. 20. Sources of Arsenic  Pesticides  Mining, smelting of gold, lead, copper and nickel  Production of iron and steel  Combustion of coal  Leachate from abandoned gold mines  Used as a wood preservative  Herbicides  Tobacco smoke  Wallpaper paste and pigments in wallpaper
  21. 21. Health effects  Birth defects  Carcinogen: Lung cancer results from the inhalation of arsenic and probably also from its ingestion. Skin and liver cancer, and perhaps cancers of the bladder and kidneys, arise from ingested arsenic  Gastrointestinal damage  Severe vomiting  Diarrhea  Death •Causes arsenic keratosis of skin
  22. 22. Arsenic in drinking water in US
  23. 23. General sources of heavy metals in residential houses • Infiltration from outside, along with the dust carried on shoes and clothes • Indoor sources include old-lead and latex based paints, domestic water supply, burning of wood, and tobacco smoke • Pesticides and fungicides are major sources of arsenic and mercury indoors
  24. 24. Methods for measurement of trace metals  Most common method of collecting particulate matter is through filters  Identification and concentration of individual trace metals like lead, cadmium, arsenic, mercury and chromium is determined by  Atomic absorption spectrophotometer  X-ray fluorescence  Atomic absorption spectrophotometry is a destructive method and requires at least 1 to 2 ml of solution  X-ray fluorescence is a nondestructive method and works independent of the chemical state of the sample.
  25. 25. Control strategies
  26. 26. Control methods • Periodic vacuuming of the house can be effective in removal of these pollutants • Replacement of wood-burning by an equivalent gas or electrical appliance • Removal of old lead and mercury-based paints • The effective method for removal of mercury vapors is by the use of packed bed of absorbents • Gold-coated denuder can also be used for the removal of mercury from air

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