For group projects

2.  6500 BC. - Lead discovered in Turkey, first mine.
 500 BC-300 AD.- Roman lead smelting produces dangerous
emissions.
 100 BC. - Greek physicians give clinical description of lead
poisoning.
 1854 - Tetraethyl lead discovered by German chemist.
 1921 - Midgley discovers that tetraethyl lead curbs engine
knock.
 Half-life Of Lead - 25 DAYS:BLOOD. 40 DAYS:SOFT TISSUE.
20 YEARS:BONE
 Lead can be inhaled.
 Tetraethyl lead can be absorbed via skin.
 Cigarettes are the major source of Lead.

3. GASOLINE
FOOD
SOIL
WATER
WORK EXPOSURE

5. Lack of Concentration
Miscarriage & Infertility
Nausea
Dyspepsia
Anaemia
Hypertension
Fatigue

6. DOs
Use unleaded petrol.
Safely dispose Lead
batteries.
Take more Ca & Fe in diet.
Avoid smoking.
Wear gloves while
soldering.
DON’Ts

7. Acknowledgement
We would like to thank our teachers for allowing us to make this
project.
It helped us to acquire a lot of information of the topic, without which
we would have remained in the dark about such serious threats to
ourselves and our environment.

8. Bibliography
The following sites and books were helpful in the
completion of the project:-
 NCERT Biology for Class XII
 www.google.com
 www.wikipedia.org