2 Environmental Pollutants and Their Toxicity
in Environment
Pollutants in the environment are of several categories like organic, inorganic, and
radioactive and some other metals. Inorganic pollutants are mainly nitrate, sodium,
arsenic, or ammonia, whereas metallic pollutants are characterized by cadmium,
copper, mercury, chromium, and selenium. Uranium, strontium, and cesium are the
main radioactive substances causing pollution in the environment. Organic pollutants are the main source of environmental pollution. It includes various compounds
like bentazon and atrazine as pesticides; polycyclic aromatic hydrocarbons (PAHs);
petroleum hydrocarbons such as toluene and benzene; and trichloroethylene which is
a chlorinated solvent. There are some other very hazardous pollutants being released
into the environment unintentionally or intentionally and posing global concern for
their remediation. These lipophilic chemicals are called as persistent organic pollutants (POPs) because they get accumulated in different biological systems present in
the environment like animal tissue and are resistant to photochemical and biodegradation resulting in longtime presence in the environment (Buccini 2003; Wong et al.
2005; Sharma et al. 2014). Recent advancement in day to day life of humans has led
to the increase in the utilization of nanoparticles in cosmetics, but in most of the
cases, besides their benefits, the negative effects observed on the environment
requires mineralization or removal of these toxic chemicals (Landis and Yu 2003).
According to Kuppusamy et al. (2016), there is a list of toxic pollutants mainly
inorganic and organic (as demonstrated in Fig. 17.1.) which exert risk to health of
more than 100 million people if exposure occurs.
The exposure to these toxic pollutants may have adverse health impacts like
organ dysfunction, cancer, mental and physical disorders, neurological disorder, and
reduced immune system and ultimately causes death (Godduhn and Duffy 2003;
Perera and Herbstman 2011; Mates et al. 2010; Yu et al. 2011; Huang et al. 2012).
Since the adverse effects of various kinds of environmental pollutants, the
demand has increased to develop a suitable technology for lowering the cost of
pollutant treatment because the remedial sector plays an important role in strengthening the GDP. In this respect, the selection of already available technology for
better applicability directly depends upon the characteristics of polluted site and task
objectives. Therefore, a combination of all the adopted methods for remediation of
pollutants such as biological and physicochemical means is the most promising
option in present scenario (Kuppusamy et al. 2016).
17 Plant-Microbe Interactions for Bioremediation and Phytoremediation of. . .
417
in Environment
Pollutants in the environment are of several categories like organic, inorganic, and
radioactive and some other metals. Inorganic pollutants are mainly nitrate, sodium,
arsenic, or ammonia, whereas metallic pollutants are characterized by cadmium,
copper, mercury, chromium, and selenium. Uranium, strontium, and cesium are the
main radioactive substances causing pollution in the environment. Organic pollutants are the main source of environmental pollution. It includes various compounds
like bentazon and atrazine as pesticides; polycyclic aromatic hydrocarbons (PAHs);
petroleum hydrocarbons such as toluene and benzene; and trichloroethylene which is
a chlorinated solvent. There are some other very hazardous pollutants being released
into the environment unintentionally or intentionally and posing global concern for
their remediation. These lipophilic chemicals are called as persistent organic pollutants (POPs) because they get accumulated in different biological systems present in
the environment like animal tissue and are resistant to photochemical and biodegradation resulting in longtime presence in the environment (Buccini 2003; Wong et al.
2005; Sharma et al. 2014). Recent advancement in day to day life of humans has led
to the increase in the utilization of nanoparticles in cosmetics, but in most of the
cases, besides their benefits, the negative effects observed on the environment
requires mineralization or removal of these toxic chemicals (Landis and Yu 2003).
According to Kuppusamy et al. (2016), there is a list of toxic pollutants mainly
inorganic and organic (as demonstrated in Fig. 17.1.) which exert risk to health of
more than 100 million people if exposure occurs.
The exposure to these toxic pollutants may have adverse health impacts like
organ dysfunction, cancer, mental and physical disorders, neurological disorder, and
reduced immune system and ultimately causes death (Godduhn and Duffy 2003;
Perera and Herbstman 2011; Mates et al. 2010; Yu et al. 2011; Huang et al. 2012).
Since the adverse effects of various kinds of environmental pollutants, the
demand has increased to develop a suitable technology for lowering the cost of
pollutant treatment because the remedial sector plays an important role in strengthening the GDP. In this respect, the selection of already available technology for
better applicability directly depends upon the characteristics of polluted site and task
objectives. Therefore, a combination of all the adopted methods for remediation of
pollutants such as biological and physicochemical means is the most promising
option in present scenario (Kuppusamy et al. 2016).
17 Plant-Microbe Interactions for Bioremediation and Phytoremediation of. . .
417