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Topic 5 – Continued… November 9, 2010

Pollution in the Environment Science 7Page 52

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Pollution in the EnvironmentPollution occurs when a substance is added to the environment at such a fast rate that it cannot be broken down, stored or recycled in the air, land, or water in a non-damaging form.

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Pollution in the EnvironmentPollutants are substances that cause pollution.

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Pollution in the Environment

Example #1 Example #2

Type of polluta

ntAcid rain

Carbon dioxide

Reason they are

classified as

pollutants

Sulfur and Nitrogen at higher than

normal levels in the air, which mix

with water to produce acidic precipitation.

Burning of Fossil fuels puts higher

than normal levels of CO2 into the

atmosphere and the ozone layer

(which protects us from radiation is being depleted.

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Pollution in the EnvironmentMany substances occur naturally in the environment become pollutants because they are present in high concentrations .◦Carbon dioxide is found naturally in our environment but the excess is damaging the environment

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BrainPOP!Air Pollution

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The Movement of PollutionMany harmful substances move through our environments◦Examples: PCBs – was used in paints and packaging materials; break down slowly and harm organisms

Mercury – industries; cause deformities in organisms

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DDTWhat is it?d ichlorod iphenyltrichloroethaneSynthetic pesticide

◦Made in a chemistry labUsed to kill pests after WWII

◦Very eff ective at kil l ing mosquitoes

Advertised as “Safe for Everyone”

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-DDT use in the 1940-1960s-Banned in the 1970s-stilled used to kill pests in areas where diseases are persistent (Malaria)

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Poisons cause deformities in frogs

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BioaccumulationAccumulation of pollutants/toxins in a food web

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BioaccumulationPollutants enter in the lower levels of the food web and increase or accumulate as you move up the web

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Bioaccumulation For example, a robin takes in all the pollutants that the worms ate, then a falcon eats all the poison both the worms and robin ate.Fa lc o g yrfa lc o

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AssignmentPage 54Complete question # 1 to 5

To be handed in!