Xenobiotics: The word xenobiotic is derived from Greek word xenos mean foreigner or stranger. Xenobiotics are man made chemicals that are foreign in nature. Xenobiotics can not be produced naturally. Thermodynamically stable in environment. Produce adverse effects in human: Cell injury Toxicity Cancer Physiological and immunological effects.

1. Reported By:
Farwa Butt
Muhammad Alfahad
“Environmental science”

2.  Introduction………………………….
 Effects of xenobiotics………………..
 Sources……………………………….
 Biodegradation……………………….
 Distribution and storage……………..
 Mechanism………………………......
 Factors affecting on metabolism…….

3. Introduction
 Xenobiotics:
• The word xenobiotic is derived from Greek word xenos
mean foreigner or stranger.
• Xenobiotics are man made chemicals that are foreign in
nature.
• Xenobiotics can not be produced naturally.
• Thermodynamically stable in environment.
@alfahadfarwa

4. Produce adverse effects in human:
• Cell injury
• Toxicity
• Cancer
• Physiological and immunological
effects.
@alfahadfarwa

5. @alfahadfarwa

6. Exogenous xenobiotics:
The foreign molecules which gain entry through dietary
food stuffs, or in the form of certain medicines used for a
therapeutic cause or inhaled through environment.
Example:
Drugs, Food additives and Pollutants
@alfahadfarwa

7. Endogenous Xenobiotics:
They are not foreign substances but have effects similar
to exogenous xenobiotics. These are synthesized naturally
in the body.
Examples:
Bile acids, Steroids and certain fatty acids.
@alfahadfarwa

8.  Environmental pollution:
◦ Pesticides and fertilizers
◦ Industrial and automobile
chemicals
◦ Radiations
 Drugs:
◦ Antibiotics
 Cosmetics:
◦ Synthetic chemicals
◦ Heavy metals
 Toxic Foods:
◦ Pesticides and fertilizers
accumulation
◦ Heavy metals accumulation
◦ Food additives
◦ Dyes
@alfahadfarwa

9. @alfahadfarwa

10.  Degradation means decay and bio mean organisms;
bacteria, fungi, insects and worms.
 Biodegradation is a process by which organic
substances are decomposed by using microorganisms
into simpler substances such as carbon dioxide, water
and ammonia.
 Natural process play a major role in the removal
of contaminants.
@alfahadfarwa

11.  Number of factors determine the rate at which this degradation
of organic compounds occur.
Factors include :
• Light
• Water
• Oxygen
• Temprature
There of three phases of biodegradation:
 Natural attenuation
 Biostimulation
 Bioaugmentation
@alfahadfarwa

12. “Natural attenuation”
First natural attenuation, contaminants are reduced
by native microorganisms without any human
interfere
“Biostimulation”
Second, biostimulation is employed where nutrients
and oxygen are applied to the systems to improve
their effectiveness and to accelerate biodegradation.

13. Bioaugmentation:
Finally, during bioaugmentation, microorganisms
are added to the systems. These supplemental
organisms should be more efficient than native flora
to degrade the target contaminant.

14. @alfahadfarwa

15. @alfahadfarwa

16.  Xenobiotics are distributed through peripheral tissues via blood, lymph and CSF.
These are stored:
 Liver:
Food contaminants
Drug deposits
 Body fat:
Pesticide
Organophosphate
DDT
@alfahadfarwa

17. Bone:
These chemicals are stored in bones:
• Fluoride
• Lead
• Cadmium
• Radium
• Plutonium

18.  Mechanism of xenobiotics have two phases:
 Phase I:
• Biotransformation
• Oxidation
• Reduction
• Hydrolysis
 Phase II
• Conjugation

19. Metabolism of xenobiotics

22. This reaction involves the break down of any
bond in a molecule using water.
Biotransformation of xenobiotic occur
through hydrolysis is done by hydrolytic
enzyme.

24. @alfahadfarwa

25. @alfahadfarwa

26.  Say “NO” to plastic:
• PVC ; Commonly found in condiments and salad dressing and
cheep baby toys.
• Use in styrofoam coffe cups and containers.
 Wash vegetables and fruits.
 Pragnant mothers:
Should consult her physician before taking any
suppliments.
@alfahadfarwa

27. Be volatile organic compounds free:
• New paint
• Furnishings
• Carpeting
Wise selection of cosmetics.
@alfahadfarwa

28. @alfahadfarwa