Some pollutants are called criteria air pollutants. These include ozone, particulate matter, carbon monoxide, sulfur dioxide, lead, nitrogen dioxide.
Other pollutants are called hazardous air pollutants. They include asbestos, radio nuclides, beryllium, mercury, vinyl chloride, arsenic, benzene and oven emissions. Other common air pollutants are chlorinated hydrocarbons, organic phosphates, fluorides, and hydrochlorofluorocarbons. Some act together, for example, in car exhausts. Reason have been given for the necessity of each but their effect on the ecosystem proves different.
Acid rain forms when compounds in the air react with the water to form acids that then rain down on the whole environment.
Insecticides and herbicides are sprayed and leave poison on living things particularly near water. This happens to spread through the food chain. For example, a small fish may eat some green plant sprayed with a poison. The fish, in turn, is eaten by a larger fish which gets caught by a fisherman and sold to the local supermarket. Of course, it is then purchased by you, prepared, then eaten. You may get a little sick from just one fish, but over a period of time and eating more fish the poisons build up in your system and eventually you die. All kinds of reasons may be given for your death but the connection between the poison spray on the plant life and you eating that fish probably won’t be one of the reasons. A good example of this is the mercury in fish-a little is unnoticeable but it accumulates over time.
The children who play in or near the area where the toxins were sprayed are at risk of getting sick just by inhaling and coming in physical contact with the chemicals. They live closer to the ground allows for greater exposure and possible damage to be done to them.
Now that we have established what our purpose and objectives are for the unit let’s look at....
LESSON #l-The Ecosystem & Contaminants
Main Idea:
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Everything we do affects someone or something.
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LET’S DO POSITIVE AND BENEFICIAL THINGS.
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Objective:
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Define Ecosystem. Compare a food chain with contaminants to a food chain without contaminants. Develop food chain posters.
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Time:
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three (3) days 30 minutes each day
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Materials:
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Dictionary/encyclopedia, paper pencil, books on birds, books on plants, markers, nature magazines, poster board paper, two (2) small plants, water, alcohol.
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Procedures:
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Teacher will post a chart on the board of a generalized cycle of materials in an ecosystem. An explanation will be given. 1. In groups of three, all students will research ecosystems. 2. Two of the groups will research one type of small fish and a larger fish that eats him. 3. Two groups will research plants that are eaten by fish. 4. One group will care for one plant with sunlight and water. 5. One group will care the other plant with sunlight and alcohol.6. The plant caretakers will water or alcohol their plants everyday for three days and record any changes observed on a daily basis. 7. All groups will make a food chain poster using pictures from the magazines, or those drawn by hand. Humans do not have to be at the top of their food chains. 8. By day three, each group will present an oral report of what they found. 9. The class will decide which of the two plants they would want to feed the fish they would eat and why. What happened to the plant not chosen.
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Conclusion:
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1. What would eventually happen to any living creature who is at the top of a food chain where poisons have been consumed along the way?
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(Answer-it depends on the poison-some are passed along-others are not. Metals accumulate - hydrocarbons accumulate - organophosphates do not).
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2. How do contaminants move through an ecosystem?
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