3.9 Zinc
Zinc (Zn) is a lustrous bluish-white metal brittle and crystalline at ordinary temperatures, but it becomes ductile and malleable when heated between 110
C and
150
C. The major sources are industrial activities, such as mining, steel processing,
coal and waste combustion (Raut et al. 2012), galvanization, smelting, paint, fertilizers, pesticides, batteries, fossil fuel combustion, etc. (Holdren et al. 1991). Zinc is
generally considered nontoxic, but overdose toxicity causes symptoms like nausea,
lethargy, vomiting, epigastric pain, and fatigue.
3.10 Aluminum
Aluminum (Al) is the third most abundant metallic element and constituting about
8% of the Earth’s crust present in only one oxidation state (+3) in the environment. It
occurs naturally as silicates, oxides, hydroxides, organic matter complexes, and
complexes with other elements like sodium and fluoride in the environment. Toxicity of aluminum is highly influenced by pH of water and organic matter and increases
with a decrease in pH (Jeffrey et al. 1997). The main entry modes in humans are
through inhalation, ingestion, and dermal contact with the sources being drinking
water, beverages, and aluminum-containing drugs and food. A higher dose causes
nausea, skin rashes, mouth ulcers, diarrhea, skin ulcers, vomiting, and arthritic pain
in humans as Mg2+ and Fe3+ are replaced by Al3+ and osmoregulatory failure in
aquatic animals by damaging the plasma and hemolymph ions which causes many
disturbances associated with intercellular communication, cellular growth, secretory
functions, and secondary hyperparathyroidism, leading to other diseases such as
aluminum-induced adynamic bone disease and aluminum-induced osteomalacia.
3.11 Iron
Iron (Fe) being the second most abundant metal on the earth’s crust is a very
essential element for all living organisms (Valko et al. 2005). It is a vital component
of algae, enzymes, and oxygen-transporting proteins (hemoglobin and myoglobin)
and exists in ferrous (Fe2+) and ferric (Fe3+) oxidation states. The major anthropogenic sources are iron and steel industry, iron mining, fertilizer, and herbicide. A
higher dose affects gastrointestinal tract and biological fluids with free ions penetrating into cells of the heart, liver, and brain.
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M. Rastogi and M. Nandal
Zinc (Zn) is a lustrous bluish-white metal brittle and crystalline at ordinary temperatures, but it becomes ductile and malleable when heated between 110
C and
150
C. The major sources are industrial activities, such as mining, steel processing,
coal and waste combustion (Raut et al. 2012), galvanization, smelting, paint, fertilizers, pesticides, batteries, fossil fuel combustion, etc. (Holdren et al. 1991). Zinc is
generally considered nontoxic, but overdose toxicity causes symptoms like nausea,
lethargy, vomiting, epigastric pain, and fatigue.
3.10 Aluminum
Aluminum (Al) is the third most abundant metallic element and constituting about
8% of the Earth’s crust present in only one oxidation state (+3) in the environment. It
occurs naturally as silicates, oxides, hydroxides, organic matter complexes, and
complexes with other elements like sodium and fluoride in the environment. Toxicity of aluminum is highly influenced by pH of water and organic matter and increases
with a decrease in pH (Jeffrey et al. 1997). The main entry modes in humans are
through inhalation, ingestion, and dermal contact with the sources being drinking
water, beverages, and aluminum-containing drugs and food. A higher dose causes
nausea, skin rashes, mouth ulcers, diarrhea, skin ulcers, vomiting, and arthritic pain
in humans as Mg2+ and Fe3+ are replaced by Al3+ and osmoregulatory failure in
aquatic animals by damaging the plasma and hemolymph ions which causes many
disturbances associated with intercellular communication, cellular growth, secretory
functions, and secondary hyperparathyroidism, leading to other diseases such as
aluminum-induced adynamic bone disease and aluminum-induced osteomalacia.
3.11 Iron
Iron (Fe) being the second most abundant metal on the earth’s crust is a very
essential element for all living organisms (Valko et al. 2005). It is a vital component
of algae, enzymes, and oxygen-transporting proteins (hemoglobin and myoglobin)
and exists in ferrous (Fe2+) and ferric (Fe3+) oxidation states. The major anthropogenic sources are iron and steel industry, iron mining, fertilizer, and herbicide. A
higher dose affects gastrointestinal tract and biological fluids with free ions penetrating into cells of the heart, liver, and brain.
268
M. Rastogi and M. Nandal