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Investigation On The Occurence Of Heavy Metals In Yoghurt Sold
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CHAPTER ONE
1.0 INTRODUCTION
Increasing industrialization
has been accompanied throughout the world by the extraction and
distribution of mineral substances from their natural deposits.
Following
concentration, many of these undergone chemical changes through
technical processes and finally pass by way of effluent, sewage dumps
and dust into the water, the earth and the air and thus into the food
chain.
The term heavy metal refers to any metallic chemical element
that has a relatively high density and is toxic or poisonous at high
concentrations. Examples of heavy metals include Mercury (Hg), Cadmium
(Cd), Arsenic (As), Lead (Pb), Chromium (Cr), Thallium (Ti). Heavy
metals are natural components of the earth’s crust. They cannot be
degraded or destroyed. To a small extent they enter bodies via food,
drinking water and air. For food analyst they are termed contaminants
which are undesirable materials, which have been added to advertently
before, during or after processing of foods. Heavy metals are dangerous
because they tend to bioaccumulate. Bioaccumulation means an increase
in the concentration of the chemical in biological organism overtime
compared to the chemical concentration in the environment, compounds
accumulate in living things anytime they are take up and stored faster
than they are broken down or excreted.
During the early life most
substances that people were likely to encounter in their daily lives
were derived with little modification from the earth, the animals,
vegetables, crops or the mineral sources. Today, there is an extensive
existence of synthetic chemical in the environment a class, which was
not present until their creation by human scientific and industrial
effort. The domination of chemicals is increasing in our lives, can we
imagine life without Agrochemicals, pharmaceuticals, preservatives,
colourants, plastics, etc. (Envis Newsletter, 2002). Heavy metals can
enter a waste or even from acidic rain breaking down soils and many
heavy metals into streams, lakes, rivers and ground water.
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ABSRACT - [ Total Page(s): 1 ]24 samples of different brands of yoghurt were collected from 2 popular Lagos market and Atomic Absorption Spectrophotometer was used for the determination of heavy metals i.e. Lead, Cadmium and Chromium. 100% of the samples were found to have the concentration of heavy metals below the safe limit recommended by world health Organization (WHO). The concentration of Lead, Cadmium and Chromium fall between 0.52ppm – 0.92ppm, 0.14ppm – 0.49ppm and 0.26ppm – 0.75ppm respec ... Continue reading---
