impact on the environment and public health. Products such as hydroxybenzenes or
phenols and their analogues are recognized as priority pollutants (Sarkar et al. 2003),
enter the environment through numerous chemical industries, as well as the use of
herbicides and pesticides in agriculture (Hijosa-Valsero et al. 2013). These compounds are mainly carcinogenic, and their impact on the environment is important,
causing damage to the human being and the biota that comes in contact with them
(Azizullah et al. 2011). Due to its chemical nature, most organic pollutants are
hydrophobic which makes them insoluble in water and accumulates on the surface
of water bodies. It is known that these compounds can agglutinate with other
substances, forming sediments that are ingested by aquatic animals, creating
bioaccumulation within their tissues, resulting in danger for the trophic chains and
therefore, for the human being, since they could ingest intoxicated animals (Vrana
et al. 2006).
Among the recognized priority organic pollutants are three groups: chlorinated
organic pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons.
Organochlorine pesticides (OCP) are substances that began to be used in the ‘70s
in the United States and part of Europe. These compounds tend to bioaccumulate in
adipose tissues, and there is evidence that there is a close relationship between these
substances and the development of neuronal diseases such as Parkinson’s disease
(Fleming et al. 1994). Although these pollutants have already been banned, they are
still found in the environment, since they have a period of degradation close to
20 years. Likewise, in developing countries, some compounds such as dichloro
diphenyl trichloroethane DDT continue to be used to combat disease transmission
vectors such as malaria and dengue (Harner et al. 1999), what ultimately keeps them
current as contaminants.
On the other hand, the polychlorinated biphenyls (PCB) are part of the group of
halogenated aromatic compounds. The PCBs were produced by the chlorination of
biphenyl, and the resulting products were marketed according to their chlorine
content percentage (Safe 1985). The chemical properties that are mainly responsible
for many of the industrial applications of PCBs, that is, their flammability, chemical
stability and miscibility with organic compounds (lipophilicity), are also the same
properties that have contributed to their environmental problems. Once introduced
into the environment, stable PCBs degrade relatively slowly and undergo transport
cycles within the various components of the global ecosystem (Safe 1994).
Likewise, polycyclic aromatic hydrocarbons (PAH) are the product of the incomplete combustion of fossil fuels and have a high presence in the environment
(Haritash and Kaushik 2009). Some of these chemicals are worrisome to the
environment due to their genotoxic and carcinogenic potential and their persistence
in the environment (Cerniglia 1993). There are multiple forms of degradation of
these compounds; however, compounds with rings of 5 or 6 carbons are usually
difficult to break down by biological and physicochemical means.
Concerning the inorganic pollutants, it is necessary to mention first that an
inorganic compound can be considered as a compound that does not contain a
carbon-hydrogen bond besides since many inorganic compounds contain some
metal, which tends to be able to conduct electricity. The principal inorganic water
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S. M. Sathianesan Vimala et al.
phenols and their analogues are recognized as priority pollutants (Sarkar et al. 2003),
enter the environment through numerous chemical industries, as well as the use of
herbicides and pesticides in agriculture (Hijosa-Valsero et al. 2013). These compounds are mainly carcinogenic, and their impact on the environment is important,
causing damage to the human being and the biota that comes in contact with them
(Azizullah et al. 2011). Due to its chemical nature, most organic pollutants are
hydrophobic which makes them insoluble in water and accumulates on the surface
of water bodies. It is known that these compounds can agglutinate with other
substances, forming sediments that are ingested by aquatic animals, creating
bioaccumulation within their tissues, resulting in danger for the trophic chains and
therefore, for the human being, since they could ingest intoxicated animals (Vrana
et al. 2006).
Among the recognized priority organic pollutants are three groups: chlorinated
organic pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons.
Organochlorine pesticides (OCP) are substances that began to be used in the ‘70s
in the United States and part of Europe. These compounds tend to bioaccumulate in
adipose tissues, and there is evidence that there is a close relationship between these
substances and the development of neuronal diseases such as Parkinson’s disease
(Fleming et al. 1994). Although these pollutants have already been banned, they are
still found in the environment, since they have a period of degradation close to
20 years. Likewise, in developing countries, some compounds such as dichloro
diphenyl trichloroethane DDT continue to be used to combat disease transmission
vectors such as malaria and dengue (Harner et al. 1999), what ultimately keeps them
current as contaminants.
On the other hand, the polychlorinated biphenyls (PCB) are part of the group of
halogenated aromatic compounds. The PCBs were produced by the chlorination of
biphenyl, and the resulting products were marketed according to their chlorine
content percentage (Safe 1985). The chemical properties that are mainly responsible
for many of the industrial applications of PCBs, that is, their flammability, chemical
stability and miscibility with organic compounds (lipophilicity), are also the same
properties that have contributed to their environmental problems. Once introduced
into the environment, stable PCBs degrade relatively slowly and undergo transport
cycles within the various components of the global ecosystem (Safe 1994).
Likewise, polycyclic aromatic hydrocarbons (PAH) are the product of the incomplete combustion of fossil fuels and have a high presence in the environment
(Haritash and Kaushik 2009). Some of these chemicals are worrisome to the
environment due to their genotoxic and carcinogenic potential and their persistence
in the environment (Cerniglia 1993). There are multiple forms of degradation of
these compounds; however, compounds with rings of 5 or 6 carbons are usually
difficult to break down by biological and physicochemical means.
Concerning the inorganic pollutants, it is necessary to mention first that an
inorganic compound can be considered as a compound that does not contain a
carbon-hydrogen bond besides since many inorganic compounds contain some
metal, which tends to be able to conduct electricity. The principal inorganic water
120
S. M. Sathianesan Vimala et al.