Toxic Pollution 149
those caused by natural erosion. Substantial cadmium pollution is caused
by the industrial production of zinc and phosphate fertilisers. The presence
of cadmium in the sludge resulting from waste processing reflects industrial
and household use of cadmium.
Cadmium is easily taken up by plants and enters their edible parts. For
non-smokers, the main agent of entry into the body is food. The rate of entry
in relatively unpolluted areas is 30–60 μgr per person per day—the same order
as the maximum permissible uptake set by the World Health Organisation.
That is why any cadmium burden should be avoided. Additional quantities
enter the body through respiration. Smokers run much greater risks, since
smoking 20 cigarettes adds 40 μgr of cadmium to the organism.
Cadmium has a long half-life in the human body, and thus it accumulates over time. It mainly affects the nerves and the liver, and some studies
have indicated that it may be carcinogenic and teratogenic. The regulations
of the European Union have set a maximum permissible concentration in
drinking water and bodies of water. The US EPA has set a very low limit
for drinking water.
7.4.4 chromium
Chromium (Cr) can be found in the environment in various forms—as a
valent, whereas the metallic and hexavalent forms are produced by industrial processes. Of the chromium existing in the environment, only a small
fraction is soluble in water, and fish do not accumulate great quantities of
chromium in their bodies. Humans may be exposed to chromium through
food, respiration, skin contact in the workplace, ingestion of polluted water
or by living near polluted areas. Trivalent chromium is an essential dietary
trace element that assists in the metabolism of sugars, proteins and fats.
Inhalation or ingestion of high concentrations of hexavalent chromium
damages the respiratory or peptic system respectively, as well as the liver
and kidneys, and may even cause death; it can also lead to lung cancer.
Contact with certain compounds of hexavalent chromium causes skin injuries, and some people are highly allergic to chromium. The US EPA has set
a low limit for drinking water.
7.4.5 nickel
Nickel (Ni) is a metal that is abundant in nature. It forms water-soluble
chemical compounds. It is used in alloys for the manufacture of coins,
jewelry , batteries and other products. It is released into the air and water
from industrial activities. No significant concentrations have been discovered in fish or other animals used as food by humans. Humans are exposed
those caused by natural erosion. Substantial cadmium pollution is caused
by the industrial production of zinc and phosphate fertilisers. The presence
of cadmium in the sludge resulting from waste processing reflects industrial
and household use of cadmium.
Cadmium is easily taken up by plants and enters their edible parts. For
non-smokers, the main agent of entry into the body is food. The rate of entry
in relatively unpolluted areas is 30–60 μgr per person per day—the same order
as the maximum permissible uptake set by the World Health Organisation.
That is why any cadmium burden should be avoided. Additional quantities
enter the body through respiration. Smokers run much greater risks, since
smoking 20 cigarettes adds 40 μgr of cadmium to the organism.
Cadmium has a long half-life in the human body, and thus it accumulates over time. It mainly affects the nerves and the liver, and some studies
have indicated that it may be carcinogenic and teratogenic. The regulations
of the European Union have set a maximum permissible concentration in
drinking water and bodies of water. The US EPA has set a very low limit
for drinking water.
7.4.4 chromium
Chromium (Cr) can be found in the environment in various forms—as a
valent, whereas the metallic and hexavalent forms are produced by industrial processes. Of the chromium existing in the environment, only a small
fraction is soluble in water, and fish do not accumulate great quantities of
chromium in their bodies. Humans may be exposed to chromium through
food, respiration, skin contact in the workplace, ingestion of polluted water
or by living near polluted areas. Trivalent chromium is an essential dietary
trace element that assists in the metabolism of sugars, proteins and fats.
Inhalation or ingestion of high concentrations of hexavalent chromium
damages the respiratory or peptic system respectively, as well as the liver
and kidneys, and may even cause death; it can also lead to lung cancer.
Contact with certain compounds of hexavalent chromium causes skin injuries, and some people are highly allergic to chromium. The US EPA has set
a low limit for drinking water.
7.4.5 nickel
Nickel (Ni) is a metal that is abundant in nature. It forms water-soluble
chemical compounds. It is used in alloys for the manufacture of coins,
jewelry , batteries and other products. It is released into the air and water
from industrial activities. No significant concentrations have been discovered in fish or other animals used as food by humans. Humans are exposed