Bio magnification occurs when toxic substances like heavy metals and pesticides increase in concentration in organisms at higher levels of the food chain. Certain chemicals can accumulate over time as they pass from prey to predator. This affects humans because many foods in our diet come from animals high in the food chain. Biodegradation is the process by which microorganisms break down organic matter into simpler substances. The rate depends on factors like temperature, pH, moisture, nutrients and oxygen availability. Heavy metals like mercury, cadmium and lead are toxic even in small amounts and can bioaccumulate in organisms over time through repeated exposure and insufficient excretion.

1. USMAN KHAN
Class No : 16
5th Semester Of Environmental and Conservation
Sciences
University Of Swat
16/13/2020 6:50 AM

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• What is Bio magnification ?
• What is Biodegradation?
• Factor effecting on biodegradation rate
• Toxic heavy metals and their Bioaccumulation
• Difference between bio magnification and bio
accumulation
Content
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 Bio magnification, also known as bio amplification or
biological magnification
 The increasing concentration of a substance, such as
a toxic chemical, in the tissues of tolerant organisms
at successively higher levels in a food chain.
 certain toxic chemicals and pollutants such as heavy
metals, pesticides or polychlorinated biphenyls
(PCBs) compounds go up the food chain.
BIO MAGNIFICATION :
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 Organisms at the top of the food chain generally
suffer greater harm from a persistent toxin or
pollutant than those at lower levels.
 This affects humans because a large percentage of
the fish we consume are higher on the food chain
 Therefore likely to carry a high concentration of
potentially harmful chemicals.
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 Biodegradation is the process by which organic
substances are decomposed by micro-organisms into
simpler substances such as carbon dioxide, water
and ammonia.
 Tow types of biodegradation:
1. Aerobic biodegradation
2. An-aerobic biodegradation
Biodegradation
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 Factor effecting on biodegradation rate:
 Temperature
 PH
 Soil moisture
 Nutrients
 Oxygen
Con…
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 The term heavy metal refers to any metallic chemical
element that has a relatively high density and is toxic
or poisonous at low concentrations.
 Examples of heavy metals include:
 Mercury (hg)
 Cadmium (cd)
 Arsenic (as)
 Chromium (cr)
 Thallium (Tl) and lead (Pb).
Heavy metals
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 Bioaccumulation occurs when an organism absorbs a
substance at a rate faster than that at which the
substance is lost by catabolism and excretion.
 Examples are:
 Car emission chemicals building up in birds and
other animals.
 Mercury building up in fish.
 Pesticides building up in small animals.
Bioaccumulation
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