Heavy metal pollution from sources like industrial effluents and vehicle emissions is a growing global problem. Some key heavy metals that are toxic to humans include cadmium, lead, and mercury. Cadmium toxicity can cause vomiting, diarrhea and bone deformities. Lead exposure is linked to anemia, kidney problems, and changes in bone marrow. Mercury poisoning results in issues like diarrhea, breathing difficulties, and abdominal pain. Heavy metals are a threat because unlike some other pollutants, they do not break down in the environment.

1. By-
Manish Sahu
M.Sc. Chemistry (Final)
Sp.- Physical Chemistry

2.  INTRODUCTION
 DEFINITION
 METALS AND THEIR TOXICITY
 TYPES OF TOXICOLOGY
 TOXICITY OF METALS
 EXAMPLES OF METAL TOXICITY
 CONCLUSION
 REFERENCE

3. • INTRODUCTION
Pollution is the introduction of contaminants
into the natural environment that cause adverse
change.
Toxic heavy metals in air, soil, and water are
global problems that are a growing threat to the
environment.

4. • DEFINITION
Heavy - metal pollution an environment
pollution by metals with a high relative atomic
mass, such as lead and mercury.
These metals derive from a number of source,
including lead in petrol, industrial effluents and
leaching of metal ions from the soil into lakes
and rivers by acid rain.

5. • METALS AND THEIR TOXICITY
The power of toxicity varies from metal to
metal.
A branch of science which deals with the study
of adverse and harmful effects of chemical
agents on any biological system.

6. • TYPES OF TOXICOLOGY
Divided into five categories :-
1. Clinical toxicology
2. Industrial toxicology
3. Forensic toxicology
4. Environment toxicology
5. Economic toxicology

7. • TOXICITY OF METALS
Toxicity of a metal depends on the inherent
capacity of a metal to affect adversely any
biological activity.
Toxic metal changes the biological structure and
system of the living organism and also cause
deformity in the body or finally even death.

8. 1. CADMIUM :-
OCCURENCE :- Cadmium does not exist free in nature and
there is no specific ore from which it can be obtained.
In plant and sea animals cadmium is found in trace
amounts.
In wheat and rice cadmium is present in appreciable
amount.
Cigarette tobacco contains 70 % cadmium content
(Cd) - A.N. = 48
A.M. = 112.41

9. • USES :-
1. Cadmium is used in industries as protective
coating for iron steel & copper.
2. Cu – Cd alloys are used for manufacturing
telephone wires.
3. In electronic equipment's Ni – Cd batteries are
used.

10. • TOXICITY AND DISEASE :-
Cd
Vomiting
Diarrhoea
Abdominal pains
Hypertension
Coughing
Deformity in
bones

11. • LEAD (Pb) :-
OCCURENCE :- In the nature lead is found in
bound form of ores.
Lead is found in all living organism. In a human
body about 96% lead is present in the bones.
The concentration of lead increases with age, as
the human body is 120 mg lead but it may
increase upto 400 mg. lead is not essential metal
for mammalians.
(Pb) - A.N. = 82
A.M. = 207.2

12. • USES :-
Lead is usually deposit in bones and some soft
tissues. It is also retained by animals in liver,
kidney, muscles etc.

13. • TOXICITY AND DISEASE :-
Pb
Anemia
Truble in urine
system
Changes in bone
marrow
Irritability
Abdominal pain
Headache

14. • MERCURY (Hg) :-
OCCURENCE :-Mercury occurs as native metal
mixed with its ores. the human body contains
about 13 mg mercury , 70% of which is present
in muscle tissues.
In human body mercury is found in kidney ,
liver , intestinal and colon walls , brain , heart ,
lungs , muscles and skin.
(Hg) - A.N. = 80
A.M. = 200.6

15. • TOXICITY AND DISEASES :-
Mercury and its salts are severe health hazards.
Mercury is very toxic in nature
Its amount is more than 100 mg causes body disorders.
Mercury compound as well as its vapours are harmful
for human body. Inorganic form of mercury is also
injurious to health.

16. • TOXICITY AND DISEASE :-
Pain in
chest
HgDiarrhoea
Hemolysis
Difficulty in
breathing
Abdominal pain
Headache

17. • CONCLUSION :-
 Thus , metals with density more than 5 g/cm³ are the
major environmental pollutants referred as heavy
metal.
 The heavy metal pollution is of major concern because
like most organic pollutants the metals are not
biodegradable or perishable.