Potentially harmful substances are spread and concentrated in the environment in various ways Chapter 3 Chapter 3 Introduction The solution to pollution is not dilution What does this statement mean to you? Transport of Materials
through Air, Soil, and Water Section 3.1 Transport of Materials through Air and Water The following diagram shows the general outline of how any chemical substance gets into the environment and spreads to other areas
Release Dispersion Deposition Leaching Groundwater contamination
Ties back to pollution and our views on it Transport in Air Pollutants are carried through the air by wind The pollutant is released from a source (ex. A factory), is scattered in various directions (dispersion), and then falls to
the ground or water (deposition) Transport in Air What are some factors that affect how far a pollutant can travel in the air? Think-pair-share Wind direction and speed will influence where the pollution lands When pollutants combine with rain or snow
it is not usually carried as far Nuclear Disasters and Fallout Two recent examples include Fukushima (2011) and Chernobyl (1986) The nuclear fallout from these partial meltdowns was carried by the air Fukushima Fallout Map
Chernobyl Fallout Map Acid Rain Agent Orange - Herbicide During the Vietnam war Agent Orange was released in large amounts over the forests of Vietnam to get rid of the leaves Transport in Soil
Pollutants are carried through the soil through the process of leaching. The pollutant dissolves in water (for example fertilizer, herbicide, pesticide), and then moves downward through the soil. The type of soil will affect how much leaching occurs. Transport in Soil
Soils with a lot of clay do not allow water to soak through (prevents leaching) Sandy soils allow water to soak through (allow leaching) Some pollutants react with substances in the soil and are neutralized Acid rain can be neutralized by basic soils (soils high in calcium carbonate) Transport in Groundwater
Pollutants that move through the soil can then enter the groundwater Groundwater is water held within porous rock below the soil. If you use water from a well, you are using groundwater.
The porous nature of the rock allows the groundwater to move great distances, and carry pollutants with it
Transport in Groundwater The more porous the rock, the faster the pollutants will move
Transport in Surface Water Pollutants can also move in surface water (runoff, rivers, streams). Pollutants that dissolve easily in water will be carried a long way. Pollutants that dont dissolve well will settle in the river or stream bottom and accumulate there, causing problems for the organisms nearby.
Transport in Surface Water Examples: minerals in rocks, organic substances, leached substances from landfills, leakage from underground storage and pipelines, industrial products, de-icers, microorganisms from improperly maintained
septic tanks, household chemicals Exxon Valdez http://www.youtube.com/ watch?v=556OVZBLwjQ BP Gulf Coast Homework Assignment Check and Reflect Pg. 242
#2-5, 8-9 C+R Pg. 242 2. Two ways are by ocean currents and wind currents. 3. Water can evaporate; be taken up by plant roots; run into the street, nearby stream, or property; or move downward through the soil toward the water table. 4. Airborne and water-borne chemicals are both local and global issues because they may be in high concentrations near the source where they can do much damage, or they can
be spread with wind and water currents to make them global issues across borders. 5. The lead leached into the soil from the battery and then got into the groundwater, which then flowed into the surface water. 8. The sandy soil would require more monitoring because it allows for more water movement. Changing the Concentration of
Harmful Chemicals in the Environment Section 3.2 Chemicals in the Environment Pollutants can enter the environment in several ways: Release Dispersion
Deposition Leaching Groundwater contamination Chemicals in the Environment The best way to keep the environment
safe is to prevent potentially harmful substances from entering it. However, this isnt always practical because most human activities introduce potentially harmful chemicals into the environment. Chemicals in the Environment The concentration of pollutants in the environment can be changed using
different techniques: 1. 2. 3. 4. 5. Dispersion Dilution Photolysis
Biodegradation Phytoremediation Dispersion Dispersion: is the scattering of a substance away from its source Example: Lawn Fertilizer suppose you are fertilizing your lawn and
you spill too much in one spot, to prevent damage to the lawn in that spot, you could spread the fertilizer over a larger area. Then you would be dispersing the chemical Dilution Dilution: reduces the concentration of a
pollutant by mixing the polluting substance with large quantities of air or water Example: Bleach If you place a drop of bleach in a sink full of water, the molecule of the bleach will mix with the molecules of the water and the bleach will be diluted A fast flowing river or air mass can disperse and diluted a chemical very quickly Biodegradation
Biodegradation: When living organisms break up material Example: An example of this is when bacteria break down a dead animal. Other organisms that biodegrade are algae, fungi, protozoans and
earthworms Biodegradation These organisms produce enzymes to break part most organic substances. This can be done in aerobic (in oxygen) or anaerobic (not in oxygen) conditions. Bacterium Enzyme
Absorption Factors Affecting Biodegradability Factors that affect biodegradability are 1. 2. 3. 4.
5. Temperature Soil Moisture pH Oxygen Supply Nutrient Availability Phytoremediation Green plants can be used to remove or
degrade hazardous materials. A process referred to as phytoremediation is a technique that can be used to reduce the concentration of harmful chemicals in soil or groundwater. Phyto means plant and remediation means clean up.. Phytoremediation Plants have been used to clean up metals,
hydrocarbons, solvents, pesticides, radioactive materials, explosives, and landfill leachates. These plants are allowed to grow for some time and absorb and accumulate the contaminants in the soil, and then are harvested and burned or composted. http://www.youtube.com/watch?v=w99mGLfb4_g Photolysis While some substances degrade from
plants, others degrade from exposure to light photolysis Photolysis is the breakdown (lysis) of compounds by sunlight (photo). Photolysis An example of photolysis is the formation of ozone. Nitrogen dioxide in the presence of light breaks down to form nitrogen
monoxide and an oxygen atom. The oxygen atom then combines with an oxygen molecule to form ozone. Homework Assignment Check and Reflect Page 247 Questions: #1,2,4,5,6,8 Homework Assignment
1. Five ways of reducing the concentration of pollutants in the environment are: dispersion, dilution, biodegradation phytoremediation, and photolysis 2. Chlorine is removed from a PCB molecule before it is used as food for bacteria 4. Photolysis is the breakdown of compounds by sunlight. Photodegradable plastic is an example of photolysis 5. Phytoremediation
6. An aerobic environment is preferable because it contains oxygen that supports life. An anaerobic environment has no oxygen 8. Dispersion and dilution are different processes, although they often happen together. Dispersion is the movement of a substance away from its source. Dilution is the mixing of a substance with large quantities of water or air. A substance such as smoke is diluted as it disperses Hazardous Chemicals Affect Living Things
Section 3.3 Case Study Exxon Valdez With your pod, read over the case study on the Exxon Valdez on pg. 250 of your textbook Once you are done, you will write a newspaper article on the event Your article must include:
What happened The results The clean-up The after-effects (e.g., technology, government regulations, etc.) Homework Assignment
Check and Reflect Pg. 252 #1-2, 4, 6 Homework Assignment Solutions 2. Five ways the Exxon Valdez oil spill affected Prince William Sound could include: death of organisms (plants, animals, algae) because of decreased oxygen in the water, loss of food, toxic
effect of the chemicals, reduced number of jobs; and polluted shorelines Homework Assignment Solutions 4. Students may choose any two of the following: accumulation in plants through uptake form water and nutrients; biomagnification as a chemical moves up the food chain; attachment to particles in soil.
5. The use of pesticide to kill mosquitoes has become an issue because some people think it should not be done. They object to the use of pesticides because they kill or affect the health of other organisms besides the targeted ones, and they may accumulate in the environment. Then differing viewpoints arise, and issue results Hazardous Household Chemicals
Section 3.4 Work Time Individually work through the Check and Reflect questions on pg. 259 of your textbook by reading through the section 3.4 starting on pg. 253. Homework Assignment Solutions
1. Answers will vary, but will probably be chosen from products use or discusses in the section 2. The Workplace Hazardous Materials Information System (WHMIS) was set up to protect workers, consumers, and the environment. 3. Answers will vary. They may include: labeling; following classroom safety rules; knowing the location of MSDSs and reading them to determine proper use and storage locations for products; using locked, vented, and fireproof cabinets where necessary; using tightly fitting lids; and keeping containers upright 4. (a) Gasoline should be stored in a metal container and kept
outside in a locked shed (b) Toilet cleaner should be kept in a locked cupboard and be standing upright or high up and out of reach of small children (c) Bleach should be kept standing up in a locked cupboard or one that is high up and out of reach of small children Homework Assignment Solutions 5. (a) goggles should be worn when using the material (b) Sodium hydroxide is a base so it should not be stored with acids
(c) It should be neutralized before being flushed down a drain 6. Two reasons might be to prevent hazardous products from harming the environment for recycling which saves money 7. (a) The symbol shows that its poisonous (b) Active ingredients are carbonyl, dicofol, oxydemeton-methyl (c) It kills most insects and mites on trees, shrubs, and flowers (d) Before use: mix 15 mL of liquid with 2L of water; during use: spray to wet both sides of foliage; do not use on chrysanthemums, fruit, or vegetables (e) It can enter the body through the mouth and throat, the lungs,
or the skin (f) Its poisonous to fish
