Heavy metal and its Effects .

1. Md. Sabbir Hossain(ASH1718020M)
Department of Oceanography
Noakhali science and technology university

2.  The term heavy metals refers to any metalic chemical
element that has a relatively high density and is toxic or
poisonous at low concentrations
 They cannot be degrade or destroyed
 To a small extant they enter our bodies via food, drinking water
and air
 However at higher concentrations they can lead to poisoning..

3.  Heavy metals are natural component of the Earth's crust.
 Heavy metals become toxic when they are not metabolized by the body and
accumulate in the soft tissues

4. HAZARDOUS
HEAVY METALS
Natural Sources
Anthropogenic
Sources

5.  Heavy metals are found naturally in the earth and become concentrated as a result of
human activities. Common sources are mining and industrial waste, vehicle emissions
 COMMON HEAVY METALS:
» Aluminum
» Antimony
» Arsenic
» Barium
» Bismuth
» Cadmium
» Lead
» Mercury
» Nickel
» Uranium
» Tin

6.  These toxic elements enter the human body mostly through Food and
Water.
 HEAVY METALS Poisonous in their cations form .
 Highly toxic when bonded to short chains of carbon atoms

8.  CADMIUM(CD)
 ENVIRONMENTAL SOURCES OF CADMIUM :
 Cd compounds form ionic salts with simple anions
 Found in water in the +2 oxidation state
 By-product of zinc smelting
 Burning coals
 As pigment
 Use in paints to produce brilliant yellow color
 recycling cadmium-plated steel

9.  High intake for humans living near mines and smelters
 Smokers are also exposed
 From food supply-wheat rice, grains, seafood, organ meats
 Maximum containment level is 5ppb in US and Canada
 Acute environmental problem occurred in Jintsu River Valley
region of Japan- ouch-ouch or itai-itai

10.  Affects important enzymes
 Cause osteomalacia and kidney damage
 Cadmium pneumonitis characterizes by edema and pulmonary
epithelium necrosis

11.  Some Facts About Chromium:
 CHROMIUM Normally occurs in the form of inorganic ions
 Common oxidation states: Cr(VI) and Cr(III)
 In aerobic condition it occurs as +6 as chromate ion Suspected to be
carcinogenic
 In anaerobic condition it occurs as +3 less toxic and acts as a trace
nutrient

12.  Predominantly mined as chromate ore (FeCr2O4)
 Used to manufacture stainless and in superalloys
 Tanned leather
 Metal plating industries
 CCA treated wood
 Smelters

13.  People are exposed to chromium in these four basic ways:
 Breathing (inhalation)
 Eating of contaminated food) .
 Drinking of contaminated water .
 Skin contact (with chromium compounds/salts).
 Health effects:
The most dangerous compounds of (Cr) are Trivalent chromium (Cr3+) Hexavalent
chromium (Cr6+)
 Trivalent chromium (Cr3+) Chromium (III) may cause diseases such as heart problems.
 diabetes and metabolic disorders.
 It can cause adverse health effect such as skin rashes.
 Upset stomach and ulcers
 Respiratory problems
 Weakened immune systems
 Kidney and liver damage
 Alteration of genetic materials
 Lung cancer

14.  Some Facts About Arsenic:
 ARSENIC White arsenic As2O3 is a common poison
 Believed to cure certain ailments, impotence, prophylactic against plague
 50 Chinese drugs contain the element
 Trace amount is good for human health
 ANTROPOGENIC SOURCES OF ARSENIC
 use of its compounds in pesticides
 during mining, smelting of gold, lead. copper, and nickel
 production of iron and steel
 combustion of coal
 added to chicken feed to simulate growth and prevent diseases
 Manufacturing of glass to eliminate a green color caused by impurities of
iron compounds

15.  Acute poisoning .
 Arsenic’s lethal effect when consumed is due to gastrointestinal
damage
 ARSENIC IN DRINKING WATER one of the most serious
environmental health hazards .
 Can cause cancer
 Linked to diabetes and cardiovascular diseases
 Affects intellectual levels

16.  OCCURRENCE OF LEAD :
Lead occurs naturally in the earth crust, usually in ores such as:
o Galena (PbS) (major ore)
o Cerrusite (PbCO3)
o Anglesite (PbSO3)
o Lanarkite (PbO·PbSO3)
 ENVIRONMENTAL SOURCES/USES OF LEAD :
 Lead in automobile batteries
 Soundproofing in buildings
 Solder- alloy of lead and tin
 lining pipes, tanks, X-ray apparatus
 Weather-proofing buildings
 Protective shielding for radioactive material
 Sheathing electric cables
 Additives for gasoline

17.  IN human reproduction and Intelligence
 Pb2+ replaces Ca2+ in bones
 Pb2+ remains in bones for decade
 High levels of inorganic Pb2+ is general poison
 deleterious effects on children's behavior and attentiveness and
IQs
 Dysfunctional sperm in males
 Miscarriages and stillbirth in pregnant women

20.  Water is one of the most valuable natural resources. The quality of water is of
vital concern for the mankind since it is link with human welfare. Controlled and
uncontrolled disposal of water accidental and process spillage, mining and
smelting metalliferous ores,seawage sludge application to the agriculture soils are
responsible for transferring of contaminate into non contaminate sites as dust
leachate and contribute towards contamination of our ecosystem.
 Distribution in ecosystem :
 Biosphere is the natural environment of living object. It envelope the eaerth and
contains surficial part of lithosphere, the lower part of the atmosphere and
hydrosphere.
 Heavy metals are significant environment pollutants and their toxicity is a
problem of increasing significance for ecological, evolutionary, nutritional ans
environmental reason.

21.  Fish is high in omega-3 and protein that the human body needs
to stay healthy.
 potentially dangerous heavy metals are absorbed into the body
tissues of fish that are transferred to humans on consumption of
this affected fish. Good quality of food for human consumption
can only be produced in an environment free from contamination
and pollution.
 Several reports indicate high mortality of juvenile fish and
reduced breeding potential of adults after long term exposure to
heavy metals

22.  Bioaccumulation is the
accumulation of substances,
such as pesticides,
or other chemicals in an organism.
 Bioaccumulation occurs when an
organism absorbs a substance
at a rate faster than that at
which the substance is lost
by catabolism and excretion.

24.  Heavy metals are generally defined as metals with relatively high densities, atomic
weights, or atomic numbers. In metallurgy, for example, a heavy metal may be defined on
the basis of density, whereas in physics the distinguishing criterion might be atomic
number, while a chemist would likely be more concerned with chemical behaviour.
 The earliest known metals—common metals such as iron, copper, and tin, and
precious metals such as silver, gold, and platinum—are heavy metals.
 Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc),
or relatively harmless (such as ruthenium, silver, and indium), but can be toxic in
larger amounts or certain forms.
 Other heavy metals, such as cadmium, mercury, and lead, are highly poisonous.
Potential sources of heavy metal poisoning include mining, tailings, industrial
wastes, agricultural runoff, occupational exposure, paints and treated timber.