1.2.2 Water Pollution
The quality of water is degrading day by day due to its physical, chemical and
biological changes and adversely affecting the quality of water and living organism.
Addition of such pollutants like pesticides, heavy metals, and nondegradable,
bioaccumulative, chemical compounds dissolved or suspended solids pollutants
into water which are most insidious and persistent toxic pollutants of these polluted
water drains out with rain water and are responsible for polluting water and can be
grouped under conventional and nonconventional.
• Conventional/Classical Pollutants: These are normally associated with the undeviating input through human waste products. Rapid urbanization and rapid
population increase have produced sewage problems because treatment facilities
have not set aside pace with need. Untreated and incompletely treated sewage
from municipal wastewater systems and septic tanks in unsewered areas contribute significant quantities of nutrients, suspended solids, dissolved solids, oil,
metals (arsenic, mercury, chromium, lead, iron, and manganese), and biodegradable organic carbon to the water environment. Also, high concentrations of
suspended solids silt up rivers and navigational channels, necessitating frequent
dredging. Excess dissolved solids make the water undesirable for drinking and for
crop irrigation (Kumar et al. 2005; Mian et al. 2010).
• Nonconventional Pollutants: These are the particulate forms of metals, they are
highly toxic untested chemicals which are discharged into water pollutants from
biologically inert materials such as clay and iron residues from building and
demolishing wastes to the most toxic and dangerous materials such as
halogenated hydrocarbons (DDT, kepone, mirex, and polychlorinated
biphenyls—PCB). The chronic low-level pollutants are proving to be the most
difficult to correct and abate because of their ubiquitous nature and chemical
stability (Bhatnagar and Minocha 2006; Murad 2010). Figure 1.3 display the
blockage of water water due to house hold waste which is a common picture in
almost every part of rural and semi-urban India.
1.2.2.1 Effects of Water Pollution on Human Health
If the presence of heavy metals such as fluoride, arsenic, lead, cadmium, mercury,
etc are high in water then it is dangerous for human health. Concentrations of floride
below 0.5 mg/L causes dental caries and mottling of teeth, but exposure to higher
levels above 0.5 mg/L for 5–6 years may lead to adverse effect on human health
leading to a condition called fluorosis (Murad and Krishnamurthy 2004). Such toxic
chemicals like arsenic and cadmium are highly dangerous for human health causing
respiratory cancer and skin lesion. Long exposure to these toxic elements leads to
bladder and lung cancer. Lead contamination in the drinking water is also caused
by pipes, fitting, solder, and household plumbing systems. It may be noted that lead
exposure also affects adversely the blood, central nervous system and the kidneys of
human being, which may proove fatal for the health of child and pregnant women
(Murad and Krishnamurthy 2008).
6
S. Negi et al.
The quality of water is degrading day by day due to its physical, chemical and
biological changes and adversely affecting the quality of water and living organism.
Addition of such pollutants like pesticides, heavy metals, and nondegradable,
bioaccumulative, chemical compounds dissolved or suspended solids pollutants
into water which are most insidious and persistent toxic pollutants of these polluted
water drains out with rain water and are responsible for polluting water and can be
grouped under conventional and nonconventional.
• Conventional/Classical Pollutants: These are normally associated with the undeviating input through human waste products. Rapid urbanization and rapid
population increase have produced sewage problems because treatment facilities
have not set aside pace with need. Untreated and incompletely treated sewage
from municipal wastewater systems and septic tanks in unsewered areas contribute significant quantities of nutrients, suspended solids, dissolved solids, oil,
metals (arsenic, mercury, chromium, lead, iron, and manganese), and biodegradable organic carbon to the water environment. Also, high concentrations of
suspended solids silt up rivers and navigational channels, necessitating frequent
dredging. Excess dissolved solids make the water undesirable for drinking and for
crop irrigation (Kumar et al. 2005; Mian et al. 2010).
• Nonconventional Pollutants: These are the particulate forms of metals, they are
highly toxic untested chemicals which are discharged into water pollutants from
biologically inert materials such as clay and iron residues from building and
demolishing wastes to the most toxic and dangerous materials such as
halogenated hydrocarbons (DDT, kepone, mirex, and polychlorinated
biphenyls—PCB). The chronic low-level pollutants are proving to be the most
difficult to correct and abate because of their ubiquitous nature and chemical
stability (Bhatnagar and Minocha 2006; Murad 2010). Figure 1.3 display the
blockage of water water due to house hold waste which is a common picture in
almost every part of rural and semi-urban India.
1.2.2.1 Effects of Water Pollution on Human Health
If the presence of heavy metals such as fluoride, arsenic, lead, cadmium, mercury,
etc are high in water then it is dangerous for human health. Concentrations of floride
below 0.5 mg/L causes dental caries and mottling of teeth, but exposure to higher
levels above 0.5 mg/L for 5–6 years may lead to adverse effect on human health
leading to a condition called fluorosis (Murad and Krishnamurthy 2004). Such toxic
chemicals like arsenic and cadmium are highly dangerous for human health causing
respiratory cancer and skin lesion. Long exposure to these toxic elements leads to
bladder and lung cancer. Lead contamination in the drinking water is also caused
by pipes, fitting, solder, and household plumbing systems. It may be noted that lead
exposure also affects adversely the blood, central nervous system and the kidneys of
human being, which may proove fatal for the health of child and pregnant women
(Murad and Krishnamurthy 2008).
6
S. Negi et al.