Biological Magnification

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Biological Magnification

• Biological Magnification The process of a
  chemical buildup, increasing in concentration, as
  it moves up trophic levels of a food chain.
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Why and how do they accumulate?

• Chemicals, which bioaccumulate in this way, are
  stored in the fatty tissue of animals. Thus they
  are stored in the animal, and not used up (like a
  carbohydrate or protein) or passed out as waste.
• Thus when another animal eats them, that animal
  will gain the chemical accumulation from the
  animal they ate.

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Food Chain Concentration of DDT in A Long Island
Marsh sprayed for Mosquito Control 1967

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What chemicals biomagnifiy?

• Types of chemicals that biomagnify are often
  chlorinated hydrocarbons that are (or were) used
  to produce pesticides and heavy metals and other
  organic compounds used in industry.

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Examples are

• 1.      DDT, chlordane, and lindane. Often these
  types of chemicals are found in pesticides.
• 2.      Heavy Metals Mercury and Lead
• 3.      PCBs originally used in electrical
  transformers, it was an excellent electrical
  insulator.
• 4.      Dioxin

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POBs

• These chemicals are sometimes called persistent
  organic pollutants. (POBs) They do not degrade
  or break down easily in the environment. They
  can last for decades to hundreds of years in an
  ecosystem.
•  Consequently, even though some of these chemical
  have been banned for years, they can still cause
  problems to the environment.

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Who is at risk?

• Those most at risk from these chemicals are those
  with weakened immune systems, elderly, pregnant
  women, and children.

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Health Problems caused by biological
magnification of these chemicals are

• 1.      Neurological Damage Babies and young
  children are most susceptible to the effects of
  lead, mercury, and PCBs. Thus pregnant women are
  often at risk more due to the chemicals they can
  pass on to their babies.
• 2.      Cancer
• 3.      Reproductive Problems/Birth Defects,
• 4.      Small hard to detect health effects.