Potentially harmful substances are spread and concentrated in the environment in various ways

1. Potentially harmful substances are spread and concentrated in the environment in various ways Topic 3

2. Government Learning Outcomes • When you have completed this section, you will be able to: • Describe the transport of materials through air, soil and water • Identify factors that may accelerate or retard the distribution of chemicals • Describe how the concentration of substances can be changed in the environment • Describe ways that biodegradation occurs and interpret information about the biodegradability of material • Demonstrate how hazardous chemicals can affect the local and global environments • Identify potential risks resulting from consumer practices • Evaluate information and evidence related to an environmental issue

3. Transport of Materials Through Air, Soil and Water Section 3.1

4. When pollutants are detected far from where they are produced, many questions arise. • What is the source of a pollutant? • Who is to blame for its spread? • Who should pay to correct any environmental problems created by the pollutant?

5. Transport in Air • Three Stages of Transport of Substances in Air • Release of the chemical at the source • Dispersion of the chemical in the atmosphere (the chemicals scatter in various directions) • Deposition of the chemical in soil or water

6. Release of the Chemical • The source of a chemical that has travelled thousands of kilometers is usually impossible to identify. • Chemical travel across borders – this causes international problems • Many countries have signed international agreements and passed anti-pollution laws to limit the spread of airborne pollutants

7. Dispersion of the Chemicals – Transport in Air • The direction and distance that airborne chemicals travel are determined by various factors: • The properties of the chemical produced • The wind speed • The direction of prevailing winds • The distribution of particles may also be limited by lack of wind or precipitation

8. Dispersion of the Chemicals – Transport in Groundwater • Water that soaks into soil moves first into a zone near the surface. Spaces are filled with air and water. • As the water moves deeper, it enters the next zone where all the spaces are filled with water. This water is called groundwater. • The top of the groundwater zone is called the water table. • Groundwater can move sideways, up and down. • It moves slowly which means that dispersal of contaminants is slow, but it means that contaminants can be much more concentrated.

9. Dispersion of the Chemicals – Transport in Groundwater • Factors that affect the movement of groundwater • Number of pores in the soil • Connections of pores in the soil • Pores are the tiny spaces between soil grains. Sometimes soil grains are so tightly packed that the pores are not connected. • If pores are connected, water can flow through. • A permeable soil is one with interconnected pores.

10. Dispersion of the Chemicals – Transport in Groundwater http://www.youtube.com/watch?v=uQRvN6MUajE • The substances that contaminate groundwater occur either naturally or as a result of human activity.

11. Dispersion of the Chemicals – Transport in Surface Water • Hazardous chemicals can enter surface water from: • The air • The groundwater • Runoff from agricultural fields and industrial sites • Outflow from storm sewers and sewage treatment plants • A substance that dissolves in water easily may be carried by water a fair distance and dispersed over a wide area. • Substances that do not dissolve easily may sink to the bottom and be concentrated close to the source, affecting organisms in the immediate area. • Because humans use water for drinking and agricultural use, its quality is monitored regularly.

12. Dispersion of the Chemicals – Transport in Soil • Water landing on a farmer’s field or your front yard at home does four things: • Some evaporates • Some soaks into the soil and is taken up by plants • Some runs onto the stream or into a stream • Some soaks through the soil and moves downward. As this water moves, it dissolves substances in the soil and carries them along. This liquid is called leachate.

13. Dispersion of the Chemicals – Transport in Soil • The composition of the soil can affect the rate at which a liquid moves through it. • Ex. Packed clay is impermeable so water can’t flow through it. Landfills are surrounded with clay so that water with contaminants in it don’t soak into the groundwater. • Organic materials (such as decayed leaves) absorb water and chemicals. • Hazardous materials can be changed by chemical reactions that occur in the soil. • Ex. Acids can be neutralized by substances such as calcium carbonate (limestone) in soil.

14. Changing the Concentration of Harmful Chemicals in the Environment Section 3.2

15. Changing Pollutant Concentration • The concentration of pollutants in the environment can be changed using different techniques • Dispersion • Dilution • Biodegradation • Phytoremediation • Photolysis

16. 1. Dispersion • Scattering the substance away from its source • Example: If you accidently spill too much fertilizer in one area of your lawn, you could spread it out over the whole lawn.

17. 2. Dilution • Reducing the concentration of a pollutant by mixing the polluting substance with large quantities of air or water. • Example: Instead of pouring bleach onto a dirty shirt, you will mix it with water first so that it doesn’t ruin your shirt.

18. A fast-flowing river or air mass can disperse and dilute a chemical very quickly. However, dispersion and dilution may not leave an area clean enough to meet government standards for clean water and air.

19. 3. Biodegradation • “bio” – refers to living things • “degrade” – refers to break up • God uses living things to clean the environment and biodegrade organic substances. • Earthworms • Bacteria • Fungi • Algae • Protozoa http://www.youtube.com/watch?v=VXoz8xpwJbU&feature=related using bacteria to clean up toxic chemicals http://www.youtube.com/watch?v=EwQOD_Ir2vQ Hair used to soak up oil spills

20. 3. Biodegradation • Bacteria • Different bacteria require different environments • Aerobic biodegradation: Bacteria uses oxygen for the biodegradation process • Anaerobic biodegradation: Bacteria needs an environment without oxygen for the biodegradation process

21. 3. Biodegradation • Factors affecting biodegradation • Temperature • Soil moisture • pH • Oxygen supply • Nutrient availability • Microbial activity (bacteria and fungi living around roots of plants)

22. 4. Phytoremediation • A technique that can be used to reduce the concentration of harmful chemicals in soil or groundwater. • “phyto” means plant • “remediation” means correction or cure • Plants are being used to clean up metals, hydrocarbons, solvents, pesticides, radioactive materials, explosives and landfill leachates. • Once plants have grown and absorbed the hazardous materials, they are harvested and burned or composted. • http://www.youtube.com/watch?v=w99mGLfb4_g&feature=watch_response

23. 5. Photolysis • The breakdown (lysis) of compounds by sunlight (photo). • Example: Formation of ozone. • Companies are creating photodegradable plastics. They are made up of chemicals that react when exposed to sunlight. The plastic changes to a fine powder. • The problem: it won’t photodegrade without exposure to sunlight.

24. Hazardous Chemicals Affect Living Things Section 3.3

25. Biomagnificationhttp://www.youtube.com/watch?v=E5P-UoKLxlA animation • The increase in concentration of a chemical or element as it moves up the food chain. • Mercury can enter water systems in two ways. • One way is from the air as a result of emissions • Another way is from industrial waste fluids

27. The Exxon Valdez Oil SpillA Case Study • Some chemicals in the environment have immediate short-term effects on organisms • Some chemicals have long-term effects through concentration and accumulation. • Accumulation: increase in concentration (biomagnification) • In this case study, we will look at a chemical spill that had both short- and long-term effects. • http://www.history.com/videos/history-exxon-valdez-oil-spill#history-exxon-valdez-oil-spill

28. Crude Oil • http://www.youtube.com/watch?v=QPnJT5DQikU • Black tears

29. Crude Oil Spills

30. Impact of the Oil Spill on the Environment

31. Impact of the Oil Spill on Plants and Animals

32. Impact of the Oil Spill on People

33. Clean Up and Restoration of Prince William Sound

34. Hazardous Household Chemicals Section 3.4

35. Hazardous Household Chemicals • Chemicals used in the home and garden can be hazardous to your health. • Household cleaners • Personal hygiene products • Pet-care products • Paint and paint products • Pesticides and fertilizers • Automotive fluids • Improper transport, storage, and disposal of these products can contribute to health problems such as burns, heart, kidney, and lung ailments, cancer and even death.

36. Government Regulations • Regulations are designed to protect consumers and reduce the risk of hazardous chemicals. The regulations reflect current scientific research done on the products and how they might interact with other products.

37. Government Regulations • The government requires the use of WHMIS and MSDS. • WHMIS (Workplace Hazardous Materials Information System) • Provides information on hazardous materials used in the workplace • MSDS (Material Safety Data Sheets) • All suppliers must provide the buyer with additional information about their products.

38. What do MSDS worksheets cover? • Health effects • First aid • Physical and chemical properties • Handling and transporting information • Disposal information • Ecological information • Acetone MSDS

39. Eco-Label • Established in 1988, Canada’s "Environmental Choice" Eco-Logo program helps consumers identify products and services that are less harmful to the environment.

40. New Product Regulations • When new products are produced, the supplier must apply for approval to make it available to the consumer. • The information about the product must include: • Intended use, physical and chemical properties, active ingredient(s) • Instructions for use, safety precautions • Health effects, environmental effects, toxicity to humans, and first aid instructions in case of poisoning

42. Transportation of Consumer Goods • When it is purchased • When the unused portion is disposed of • Ways to ensure you and your family stay safe during transportation • Place the product upright and secure in the trunk (car) or box (truck). • When disposing of many products, never mix them into one container – try to keep them in their original containers with their original labels.

43. Disposal of Hazardous Chemicals • Never pour hazardous materials down the drain • They will go into the sewer system or septic tank • Never throw them away into the garbage • This can end up contaminating the soil, drinking water or air.

44. Hazardous Waste Collection Sites • Hazardous wastes such as paints and fertilizers can be taken to these sites for disposal.

47. Section Summaries

48. Bill Nye Stuff Happens • The Backyard • http://app.discoveryeducation.ca/search?Ntt=bill+nye+stuff+happens

49. Section Summaries

50. Section Summaries