225
12.3.2 Hazardous Chemical Toxicity
E-waste is different from other forms of wastes which comprise composite mixtures
of probable environmental contaminants. E-waste also contains some uncommon
potential contaminants even in other polluted sites. In the manufacturing of electrical
items, some heavy metals contaminants are used, while during combustion of
E-waste at low temperature, other contaminants such as polycyclic aromatic
hydrocarbons are produced. Important metals (Cu, platinum group) along with
potential environmental contaminants, especially Ni, Sb, Hg, Pb, Cd, polybrominated
diphenyl ethers and polychlorinated biphenyls, are generally present in the E-waste.
Dioxins, furans, polycyclic aromatic hydrocarbons, polybrominated diphenyl
ethers, polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and
dibenzofurans and hydrogen chloride could be generated due to the burning of
E-waste that are highly contaminated pollutants (Darnerud et al. 2001; Martin et al.
2003).
Open burning and labour-intensive treatment are widely used basic methods in
the recycling of E-waste. In comparison with domestic waste, ignition of insulated
wire produced 100X more dioxins (Gullett et al. 2007). Flame retardants such as
polybrominated diphenyl ethers are synthesized into plastics and other components.
Polybrominated diphenyl ethers and plastics can leach out from the surface of
E-waste into the atmosphere due to the absence of chemical bonds between them
(Deng et al. 2007). Lipophilic character of polybrominated diphenyl ethers causes
bioaccumulation in the organisms and biomagnification in the food chains (Deng
et al. 2007). Endocrine disrupting properties are also found in polybrominated
diphenyl ethers (Tseng et al. 2008). During the recycling procedures, ignition
products of polyvinyl chloride in electrical wires can emit or form a number of
highly lethal pollutants like polychlorinated biphenyls in capacitors/transformers,
polybrominated diphenyl ethers which are used as brominated flame retardants in
the circuit board and polychlorinated dibenzo-p-dioxins and dibenzofurans (Wang
et al. 2005). Soil samples were gathered by Leung et al. (2007) from the site where
it was usual to liquify circuit boards, incinerate things as cable covering to recover
copper wire and employ open-pit acid leaching for extraction of valuable metals.
Their research works concentrated on polybrominated diphenyl ethers and
polychlorinated dibenzo-p-dioxins along with dibenzofurans, that is, polybrominated
diphenyl ethers and polychlorinated dibenzo-p-dioxins and dibenzofurans.
Carcinogens in duck ponds and paddies were 263–604 ng g
−1
, dry weight and 34.7–
70.9 ng g
−1
which exceeded from control sites.
A similar study by Luo et al. (2007b) accounted that carps collected from the
Nanyang River, near Guiyu, bioaccumulated polybrominated diphenyl ethers to
high level, i.e. 766 ng g
−1
(fresh weight). Expectedly, Luo et al. (2007a) in the
further study accounted for high polybrominated diphenyl ether levels in the sediments, i.e. up to 16,000 ng g
−1
of the Nanyang River. A similar study was done
by Wu et al. (2008) and found that water snake near (the top predator) an E-waste
recycling yard had around 1091 ng g
−1
polybrominated diphenyl ethers and
12 E-waste and Their Implications on the Environment and Human Health
12.3.2 Hazardous Chemical Toxicity
E-waste is different from other forms of wastes which comprise composite mixtures
of probable environmental contaminants. E-waste also contains some uncommon
potential contaminants even in other polluted sites. In the manufacturing of electrical
items, some heavy metals contaminants are used, while during combustion of
E-waste at low temperature, other contaminants such as polycyclic aromatic
hydrocarbons are produced. Important metals (Cu, platinum group) along with
potential environmental contaminants, especially Ni, Sb, Hg, Pb, Cd, polybrominated
diphenyl ethers and polychlorinated biphenyls, are generally present in the E-waste.
Dioxins, furans, polycyclic aromatic hydrocarbons, polybrominated diphenyl
ethers, polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and
dibenzofurans and hydrogen chloride could be generated due to the burning of
E-waste that are highly contaminated pollutants (Darnerud et al. 2001; Martin et al.
2003).
Open burning and labour-intensive treatment are widely used basic methods in
the recycling of E-waste. In comparison with domestic waste, ignition of insulated
wire produced 100X more dioxins (Gullett et al. 2007). Flame retardants such as
polybrominated diphenyl ethers are synthesized into plastics and other components.
Polybrominated diphenyl ethers and plastics can leach out from the surface of
E-waste into the atmosphere due to the absence of chemical bonds between them
(Deng et al. 2007). Lipophilic character of polybrominated diphenyl ethers causes
bioaccumulation in the organisms and biomagnification in the food chains (Deng
et al. 2007). Endocrine disrupting properties are also found in polybrominated
diphenyl ethers (Tseng et al. 2008). During the recycling procedures, ignition
products of polyvinyl chloride in electrical wires can emit or form a number of
highly lethal pollutants like polychlorinated biphenyls in capacitors/transformers,
polybrominated diphenyl ethers which are used as brominated flame retardants in
the circuit board and polychlorinated dibenzo-p-dioxins and dibenzofurans (Wang
et al. 2005). Soil samples were gathered by Leung et al. (2007) from the site where
it was usual to liquify circuit boards, incinerate things as cable covering to recover
copper wire and employ open-pit acid leaching for extraction of valuable metals.
Their research works concentrated on polybrominated diphenyl ethers and
polychlorinated dibenzo-p-dioxins along with dibenzofurans, that is, polybrominated
diphenyl ethers and polychlorinated dibenzo-p-dioxins and dibenzofurans.
Carcinogens in duck ponds and paddies were 263–604 ng g
−1
, dry weight and 34.7–
70.9 ng g
−1
which exceeded from control sites.
A similar study by Luo et al. (2007b) accounted that carps collected from the
Nanyang River, near Guiyu, bioaccumulated polybrominated diphenyl ethers to
high level, i.e. 766 ng g
−1
(fresh weight). Expectedly, Luo et al. (2007a) in the
further study accounted for high polybrominated diphenyl ether levels in the sediments, i.e. up to 16,000 ng g
−1
of the Nanyang River. A similar study was done
by Wu et al. (2008) and found that water snake near (the top predator) an E-waste
recycling yard had around 1091 ng g
−1
polybrominated diphenyl ethers and
12 E-waste and Their Implications on the Environment and Human Health