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T. Sahoo et al.
7.11 Disinfection By-Products
The process of disinfection of drinking water is a successful measure for treating
wastewater (Simpson and Hayes 1998). From the literature survey, it is reported that
there is minimization of rate of mortality and morbidity by using chlorine during the
process of disinfection process of the drinking water (Li 2018). On long-term use
of chlorine in swimming pool water during disinfection, there is reaction between
organic materials present in untreated water and chlorine which leads to release of
toxic substances which increases the chances of cancer (Florentin et al. 2011). Many
disinfection by-products are reported like haloacetic acid, trihalomethanes and chloroform (Richardson 2003). The by-products produced from the process of disinfection remain suspended in treated water system in which compounds like chloroform
can remain at level of hundred parts per billion if they are not properly controlled. The
lower molecular weight compounds primarily enter body through dermal adsorption,
while bathing and inhalation, swimming in pools which are chlorinated. The substances bearing higher molecular weight affect when it is consumed. Some of the
common cancers occurring due to exposure to these disinfection by-products are
cancer of rectum, colon and bladder (Melnick et al. 2007).
7.11.1 Alkyl Phenol
These are utilized as the precursor material in the manufacture of surfactants and
detergents in industries and also used as antioxidants for producing rubber polymers
and plastic. These are also used in personal care products like hair products. Some
examples includes 4-tertiary butylphenol, 4-tertiary octylphenol and 4-nonylphenol.
Alkyl phenol are the second largest class of non-ionic commercially used surfactants
(Dekant and Völkel 2008). These are utilized in a large scale in textile, paper, plastics,
lubricating oils, detergents industries, etc. In the year 2002, its production worldwide
was approximately estimated to be around seven lakh tons (Choi et al. 2009). Sixty
per cent substances enter the sewage treatment plant and aquatic environment and
aerobically degraded with breakage of ethyl substrate sequentially into small chain
and into forms which remain persistently in environment (White et al. 1994). The
alkyl phenol metabolites get accumulated in sediments of river and sewage sludge
because they are hydrophobic in nature. They remain dispersed in soil, air and into
water bodies in sufficient amount to cause harmful impact on human health as well
as animals and environment (Dekant and Völkel 2008; Choi et al. 2009; Ying 2006).
Nonylphenol has been reported to enhance the growth of MCF-7 breast cancer cell
and simultaneously enhances the proliferation and development of mammary glands.
In addition, alkyl phenol is responsible to trigger the risk of cancer such as breast
cancer which is hormone dependent (Guenther et al. 2002).
T. Sahoo et al.
7.11 Disinfection By-Products
The process of disinfection of drinking water is a successful measure for treating
wastewater (Simpson and Hayes 1998). From the literature survey, it is reported that
there is minimization of rate of mortality and morbidity by using chlorine during the
process of disinfection process of the drinking water (Li 2018). On long-term use
of chlorine in swimming pool water during disinfection, there is reaction between
organic materials present in untreated water and chlorine which leads to release of
toxic substances which increases the chances of cancer (Florentin et al. 2011). Many
disinfection by-products are reported like haloacetic acid, trihalomethanes and chloroform (Richardson 2003). The by-products produced from the process of disinfection remain suspended in treated water system in which compounds like chloroform
can remain at level of hundred parts per billion if they are not properly controlled. The
lower molecular weight compounds primarily enter body through dermal adsorption,
while bathing and inhalation, swimming in pools which are chlorinated. The substances bearing higher molecular weight affect when it is consumed. Some of the
common cancers occurring due to exposure to these disinfection by-products are
cancer of rectum, colon and bladder (Melnick et al. 2007).
7.11.1 Alkyl Phenol
These are utilized as the precursor material in the manufacture of surfactants and
detergents in industries and also used as antioxidants for producing rubber polymers
and plastic. These are also used in personal care products like hair products. Some
examples includes 4-tertiary butylphenol, 4-tertiary octylphenol and 4-nonylphenol.
Alkyl phenol are the second largest class of non-ionic commercially used surfactants
(Dekant and Völkel 2008). These are utilized in a large scale in textile, paper, plastics,
lubricating oils, detergents industries, etc. In the year 2002, its production worldwide
was approximately estimated to be around seven lakh tons (Choi et al. 2009). Sixty
per cent substances enter the sewage treatment plant and aquatic environment and
aerobically degraded with breakage of ethyl substrate sequentially into small chain
and into forms which remain persistently in environment (White et al. 1994). The
alkyl phenol metabolites get accumulated in sediments of river and sewage sludge
because they are hydrophobic in nature. They remain dispersed in soil, air and into
water bodies in sufficient amount to cause harmful impact on human health as well
as animals and environment (Dekant and Völkel 2008; Choi et al. 2009; Ying 2006).
Nonylphenol has been reported to enhance the growth of MCF-7 breast cancer cell
and simultaneously enhances the proliferation and development of mammary glands.
In addition, alkyl phenol is responsible to trigger the risk of cancer such as breast
cancer which is hormone dependent (Guenther et al. 2002).