BIOSORPTION OF Pb2+, Cd2+, & Ni2+ FROM WATERS BY ...

potential risk for most children. Lead can accumulate in soft tissues and bone in over
time due to its potential neurotoxicity. Moreover, it can result in the decline of
performance. Anemia is another possible result of lead exposure which can replace
iron in the hemoglobine.
Serious damage of the brain and kidneys in people can take place upon
exposure to high levels of lead and death is inevitable as the end result of the process.
In addition, exposure to high levels of lead may account with miscarriage in pregnant
women and damage the organs which is responsible from sperm production. EPA
limits lead in drinking water to 15 μg/L (Environmental Protection Agency 2008).
1.2.2. Cadmium
Cadmium is one of the natural crustal elements and is generally found in the
form of oxides, chlorides, sulfates and sulfides. All rocks and soils such as coal and
mineral fertilizers contain cadmium. Batteries, pigments, metal coatings, and plastics
also contain cadmium, because it does not corrode easily. Industrial activities, mining,
coal-burning and household wastes release cadmium to the environment. Cadmium
particles in air have an ability to travel long distances before reaching to the ground
or water. It can contaminate soil or water by leakage of hazardous waste sites or from
waste disposal. While some cadmium compounds have a solubility in water, it binds
strongly to soil particles (Agency for Toxic Substances and Disease Registry 2008).
Even though it can change forms it does not break down in the nature. As cadmium
has an ability to stay in the body for a very long time, the body is susceptible to long
time exposure of low levels of cadmium.
The body can be exposed to cadmium upon breathing contaminated workplace
air (battery manufacturing, metal soldering or welding), eating foods even if it has a
low concentration in a variety of foods (highest in shellfish, liver, and kidney meats),
breathing cadmium in cigarette smoke (doubles the average daily intake), drinking
contaminated water, and breathing contaminated air near fossil burning facilities,
fuels or municipal waste. If high levels of cadmium are inhaled, lungs are seriously
damaged as well as it comes to a conclusion with death. The severe stomach irritation
is due to eat food or drink water with very high levels containing cadmium and as it
also leads to vomit and diarrhea. Storage of cadmium in the kidneys and buildup of
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