ESU4 AoS1 Pollution<br />Introduction to pollution.<br />
What is pollution?<br />“Pollution is the introduction of contaminants into a natural environment that causes instability,...
Sources of pollution.<br />POINT<br /><ul><li>A point source is when the contaminant comes from a single source – you can ...
Sources of pollution.<br />FUGITIVE<br />Fugitive emissions are usually gases that escape unnoticed – unintended or irregu...
Pollution Sinks<br />A place or process that removes, stores or absorbs the pollutant. Wetlands are a pollutant sink for h...
Wetland<br />
Toxicity<br />The measure of harm (death or illness) a substance can cause in humans and other living things. Toxicity is ...
LD50<br />Is the term used to describe the dose of a substance that is sufficient to kill a percentage (50%) of the specif...
Persistence<br />A property of a pollutant which relates to the time that the pollutant takes to break down. Substances th...
Dispersal and Transport<br />The way that a pollutant is spread or moves around the environment.<br />Dispersal can be air...
Exposure<br />The degree of time spent near or in contact with the pollutant. The level of exposure is related to the prop...
Pathways<br />Inhalation<br />When toxicants make their way into the human body through the lungs.<br />Ingestion<br />Whe...
Types of exposure and toxicity.<br />Chronic Exposure/Chronic Toxicity<br />Repeated exposure and/or absorption over a lon...
Synergistic action<br />An interaction between two or more individual compounds that produces an effect upon the body (or ...
Bioaccumulation and Biomagnification<br />When a persistent pollutant builds up in an individual organism, due to multiple...
Volatile Organic Compounds (VOC’s)<br />Volatile organic compounds are emitted as gases from certain solids or liquids. Th...
Esu4 x aos1 summary notes
Esu4 x aos1 summary notes
Esu4 x aos1 summary notes
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Esu4 x aos1 summary notes

  1. 1. ESU4 AoS1 Pollution<br />Introduction to pollution.<br />
  2. 2. What is pollution?<br />“Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms”<br />“Pollution is contamination of the natural environment with harmful substances often as a consequence of human activities.”<br />“ A Pollutant is something that when released into the environment causes some harm or alters the environment in a negative way.”<br />
  3. 3. Sources of pollution.<br />POINT<br /><ul><li>A point source is when the contaminant comes from a single source – you can pinpoint this location on a map. 
For example, a sewerage pipe, a chimney or a leaking oil tank. </li></li></ul><li>Sources of pollution.<br />DIFFUSE<br />Diffuse sources are when the exact location cannot be determined precisely. For example, exhaust gases on a highway or methane gases leaking from landfill.<br />
  4. 4. Sources of pollution.<br />FUGITIVE<br />Fugitive emissions are usually gases that escape unnoticed – unintended or irregular releases of gas, usually leaks from pressurized equipment.<br />
  5. 5. Pollution Sinks<br />A place or process that removes, stores or absorbs the pollutant. Wetlands are a pollutant sink for heavy metals and other materials. Atmospheric carbon dioxide dissolves in sea and is stored in organic matter such as plants and vegetation.<br />
  6. 6. Wetland<br />
  7. 7. Toxicity<br />The measure of harm (death or illness) a substance can cause in humans and other living things. Toxicity is defined as acute and chronic respectively this refers to single and repetitive exposure.<br />
  8. 8. LD50<br />Is the term used to describe the dose of a substance that is sufficient to kill a percentage (50%) of the specified test animal within a specified period. The smaller the LD50 dose the more toxic a substance is.<br /> The lethal dose figures refer to acute toxicity and do not give an indicator of cumulative effects over time. <br />
  9. 9. Persistence<br />A property of a pollutant which relates to the time that the pollutant takes to break down. Substances that are not easily broken down are said to be persistent. A pollutant is degradable if it breaks down with sunlight, soil, water or in chemical reactions.<br />
  10. 10. Dispersal and Transport<br />The way that a pollutant is spread or moves around the environment.<br />Dispersal can be airborne, water borne or in soils.<br />
  11. 11. Exposure<br />The degree of time spent near or in contact with the pollutant. The level of exposure is related to the properties of the pollutant.<br />
  12. 12. Pathways<br />Inhalation<br />When toxicants make their way into the human body through the lungs.<br />Ingestion<br />When toxicants make their way into the human body through the stomach.<br />Absorption. <br />When toxicants make their way into the human body through the skin.<br />
  13. 13. Types of exposure and toxicity.<br />Chronic Exposure/Chronic Toxicity<br />Repeated exposure and/or absorption over a long period of time.<br />Acute Exposure/Acute Toxicity<br />A single, severe case of exposure, absorption and harm caused.<br />
  14. 14. Synergistic action<br />An interaction between two or more individual compounds that produces an effect upon the body (or an organism) GREATER than either of the substances alone would have produced.<br />When the combined result is greater than the sum of it’s parts.<br />Example: Smog – combinations of pollutants.<br />
  15. 15. Bioaccumulation and Biomagnification<br />When a persistent pollutant builds up in an individual organism, due to multiple exposures and absorptions over time. Usually they are fat-soluble substances that are stored by the body.<br /><ul><li>When a persistent pollutant, such as DDT, mercury or arsenic moves up a food chain. It is not broken down, so accumulates in each trophic level and is magnified up the chain.</li></li></ul><li>Bioaccumulation and Biomagnification<br />
  16. 16. Volatile Organic Compounds (VOC’s)<br />Volatile organic compounds are emitted as gases from certain solids or liquids. They are usually the gaseous vapours (fumes) from paints and fuels, such as petrol or other hydrocarbons. They can be naturally occurring or man-made. 
VOCs are typically not acutely toxic but have chronic effects. Because the concentrations are usually low and the symptoms slow to develop, analysis of VOCs and their effects is a demanding area.<br />

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