This document discusses disinfection byproducts (DBPs) formed when disinfectants like chlorine react with organic matter in water. It covers the classification and factors influencing DBP formation, and the health impacts of several DBPs including increased risks of various cancers, cardiovascular disease, central nervous system effects, and adverse pregnancy outcomes. Specific DBPs are linked to thyroid cancer, lung cancer, lymphoma, liver cancer, bladder cancer, skin cancer, and impacts on the central nervous system and pregnancy. The document provides an introduction to DBPs and their role in water disinfection.

1. Group 6
Salman Elahi 201929180004
Sajid Rashid 201929180010
Farhan Iftikhar 201929180014
School Of Enviorment
Beijing Normal University
Disinfection By Products

2. Contents:
 Introduction
 Function of disinfectant
 Classification of disinfectant and its by products
 Factors causes by products
 Health Impact
 Conclusion
 References

3. Introduction
Chemicals formed through reaction of the chemical disinfectant
with naturally occurring inorganic and organic material in the source
water.

4. Function of Disinfectant
 The basic function of disinfectant is to remove the unwanted
particles like micro organisms ,virus and bacteria from the water or
from the material and make it clean.

5. Factors:
 The dose of disinfectant:
when the dose and residual of the disinfectant are higher, more disinfection
byproducts are formed.

6. Temperature
When temperatures increase, reactions take place faster, causing a
higher disinfectant concentration to be required for a proper disinfection. This
causes more THM disinfection byproducts to form.

7. pH of the water
 At higher pH values, more THM(trihalomethanes) is formed, whereas
more HAA (haloacetic acids) is formed when pH values are lower. When
pH values are high, more hypochlorite ions are formed, causing the
affectivity of chlorine disinfection to decrease. . When the pH value is
lower, more HAA are formed and when the pH value is higher,
more THM are formed.

8. Types of Disifectants

9. Chlorine
 Chlorine is the most common disinfectant
 When added to water the Following reaction occurs within a second or less:
Cl2 + H2O = HOCl + H+ Cl-

10. Chlorine dioxide
2ClO2 + H2O =6ClO2– + ClO3 + 2H+
chlorite
chlorate

11. OZONE
 Ozone is an excellent disinfectant with the superior ability to kill viruses
and biological contaminants found in water
 It is also a very powerful oxidant
 Ozone is composed of three oxygen atoms. One of the atoms is
connected to the others weakly and will transfer itself to other
substances such as viruses and bacteria, causing them to oxidize by
binding itself onto them.
 Ozone can also be created through chemical and electrolytic reactions.

12. Molecular structure of DBPs

17. carcinogenic
 During chlorination, EOM formed more N-DBPs and TOX than NOM did.
Toxicity index results showed typical DBPs from EOM chlorination were more
cytotoxic and genotoxic than those from NOM chlorination. DCAN contributed
most to cytotoxicity while both DCAN and TCNM contributed much to
genotoxicity.
 Oxidative stress in CHO cells substantially increased when exposed to
chlorinated EOM and chlorinated NOM. The elevated ROS damaged biological
macromolecules including DNA, RNA and proteins, causing increases in both
8-OH(d) G and protein carbonyls. Impaired macromolecule further triggered
cell cycle arrest at the S and G2 phases, led to cell apoptosis and eventual
necrosis.
 Chlorination increased the cytotoxicity and genotoxicity of both EOM and NOM.
The cytotoxicity and genotoxicity of chlorinated EOM were higher than those of
chlorinated NOM, indicating the potential risk in the case of unplanned indirect
potable reuse.
 Oxidative stress might be responsible for the cytotoxicity and genotoxicity as
demonstrated by adding the GSH blocker BSO. Among the reactive species

18. Thyroid gland
cancer
The thyroid gland is a small, butterfly-shaped gland
located in the neck, below the Adam's apple. The
thyroid gland produces the hormones thyroxine (also
called T4) and triiodothyronine (also called T3).
These hormones play a role in certain bodily
functions, including body temperature, mood and
excitability, pulse rate, digestion and others.
Sometimes thyroid tissue begins to grow
uncontrollably, which can cause one or
more nodules (growths) to form in the thyroid.
Cancerous nodules can invade the tissues of the neck,
spread to the surrounding lymph nodes, or to the
bloodstream, and then to other parts of the body.
DBPs (MX ,Chlorate )

19. Lung cancer:
Lung cancer, also known as lung
carcinoma, is a malignant lung tumor
characterized by uncontrolled cell
growth in tissues of the lung.
This growth can spread beyond the
lung by the process of metastasis into
nearby tissue or other parts of the
body. Most cancers that start in the
lung, known as primary lung cancers,
are carcinomas. The two main types
are small-cell lung carcinoma (SCLC)
and non-small-cell lung
carcinoma (NSCLC).
Risk factors
1)Smoking: The main factor of lung
cancer is smoking. The vast majority
85% of cases of lung cancer is tobacco
smoking.
2) Only 10 to 15 % of lung cancer
causes due to Air pollution or chemical
exposure in which some of them are
chlorinated disinfectant by products
just like NMOR, Formaldehyde,
Acetaldehyde.
DBPs ( NMOR , Acetaldehyde, Formaldehyde)

20. Lymphoma
is cancer that begins in infection-fighting
cells of the immune system, called
lymphocytes. These cells are in the
lymph nodes, spleen, thymus, bone
marrow, and other parts of the body.
DBPs(2,4,6-Trichlorophenol)

21. Liver Cancer
Liver cancer, also known as hepatic
cancer and primary hepatic cancer,
is cancer. that starts in the liver.
The most common types are hepatocellular
carcinoma (HCC), which makes up 80% of
cases, and cholangiocarcinoma.
The leading cause of liver cancer
is cirrhosis due to hepatitis B, hepatitis
C or alcohol, but some chlorinated
disinfection by products can cause liver
cancer, some of them are NDMA,
NDEA,NMEA,NMOR, NPYR, DCM,
Hydrazine, pentachlorophenol, 2,4,6-
Trichlorophenol.

22. BLADDER
CANCER
Bladder cancer is any of several types of cancer
arising from the tissues of the urinary bladder. It
is a disease in which cells grow abnormally and
have the potential to spread to other parts of the
body. Symptoms include blood in the urine, pain
with urination, and low back pain.
Risk factors:
For bladder cancer include smoking, family
history, prior radiation therapy, frequent bladder
infections, and exposure to certain chemicals,
chlorinated drinking water.
.The most common type is transitional cell
carcinoma, Other types include squamous cell
carcinoma and adenocarcinoma.
DBPs(NDMA,NDPA,NPIP)

23. Skin cancer
Skin Cancer is a disease in which
cells of the Skin grow abnormally, it is
called skin cancer
Types of Skin Cancer: there are 3
types of cancer, of which two most
common types of Skin cancer are 1)
Basal cell 2) squamous cell
carcinomas. These two are highly
curable, but can be disfiguring and
costly to treat.
3) Melanoma: The third most common
skin, is more dangerous and causes
the most deaths.
Risk factors:
1)Ultra violet rays
2)Chlorinated water
DBPs(1,3-Dichloroketone)

24. Cardiovascular
toxicity
Cardiovascular disease refers to the
ischemic or hemorrhagic effects of the
heart, and the whole body tissues.
The most common type Atherosclerosis “
which is narrowing of the blood vessels
that carry blood to the heart. This can
cause: chest pain, Heart attack, Heart
failure etc.
Because the disinfectant by products react
with the Plasma Cholesterol and form
plaque in the arteries. This plaque caused
blockage in the arteries, and in the result
Cardiovascular diseases causes, due to
which other diseases causes: just like chest
pain, Heart attack, Heart failure, and brain
hemorrhage.
DBPs(HEX)

25. Effects on pregnancy:
Disinfectant by products in
drinking water have been
associated with an increased risk
of adverse pregnancy outcomes,
including small for gestational age
at term (term-SGA) and preterm
delivery.
DBPs (Trichloroacetonitrile)

26. Central nervous
system effects
Central Nervous System
DBPs (Trichloroacetaldehyde / chloral hydrate)
Disinfectant by products have different
hazardous impacts on central Nervous
system.
Depression (major depressive disorder) is a
common and serious medical illness that
negatively affects how you feel, the way
you think and how you act Depression
causes feelings of sadness and/or a loss of
interest in activities once enjoyed.
It can lead to a variety of emotional and
physical problems and can decrease a
person’s ability to function at work and at
home.

28. Organic DBPs

35. Conclusion

36. References