Clean Water for the World


This activity broadens the lens for a more global view. The class is divided into groups representing different countries, both rich and poor. Each group must construct a water filter to clean the water that was polluted during the previous activity. However, their ability to do so will depend on which country they are in — that is, on how much money they have to purchase the materials for their filter and how easily they can read the instructions.


Time: 1-3 classes, depending on whether students do additional research on their countries.


Materials: World map, play money, country profiles and water filter instruction sheets (see “Preparation” below), clean water, dirty water from the preceding activity. In addi- tion, you will need the following materials for each group.


Materials provided “free”: • 2-litre pop bottle with the bottom cut off (used for filter)


• the bottom of a 1-litre pop bottle, or a transparent cup (used to catch filtered water)


• 500-ml measuring cup or the bottom of a plastic bottle (used to hold water for cleaning filters and to scoop dirty water from the tank for filtering)


Items to have available for “purchase”: • 1 cup fine sand • 1 cup coarse sand • 1 cup fine gravel • 1 cup coarse gravel


• 1⁄2 cup of activated charcoal, available from aquarium stores (or crush charcoal briquettes)


• 1 cotton ball • 1 small piece (about 10 cm x 10 cm) of cheesecloth • 1 rubber band


Preparation:


1. For each “country package” (one package per group of four students), create a country profile (see Country Profile template, page 32) using the data provided on the Country Data chart (see page 32). Countries may be substituted, but ensure that a wide range of afflu- ence and literacy is represented. Data for all countries can be obtained from The World Factbook by the U.S. Central Intelligence Agency at <www.cia.gov/ library/publications/the-world-factbook/index.html>. Additional water usage information can be found at the EarthTrends site of the World Resources Institute <www.earthtrends.org/>.


2. For each country, prepare instructions for making the water filter. As shown in the two examples (see page 33), countries with high literacy rates, such and Canada and the United States, should receive instructions that are completely readable. For countries with lower rates of literacy, replace some of the words with gibberish accord- ing to the literacy rate. For example, the instructions for Ghana would be approximately 58 percent gibberish to


reflect that country’s literacy rate of 57.9 percent. The diagram of the completed filter (see page 33)


may be included in all country packages. Alternatively, it may be provided only to the wealthier countries and omitted from packages for poorer countries, such as Afghanistan, Ghana and the Sudan. In that case, the diagram represents advantages, such as technology, edu- cation and health care, which make life easier in wealthier countries but are lacking in many developing nations.


3. Place play money into each country package as follows: Sweden — $1,100


United States — $1,000 Ghana — $60 Canada — $825


Afghanistan — $18


4. Prepare a price menu showing the cost of each of the materials for making the filters:


Activated charcoal $50/half cup Rubber band Cheesecloth Cotton


Gravel, coarse Gravel, fine


Procedure:


1. Begin with an overview of the quality-of-life indicators that students will encounter in this activity, such as life expectancy, literacy and population growth rate.


2. Appoint two students to play the role of the World Bank. Select students who are not likely to be intimidated by their classmates, as one of the bankers’ tasks will be to make life difficult for everyone! Divide the rest of the class into groups of four students.


3. Distribute the country packages to the groups and direct students to read their country’s statistics and locate their country on a world map. Allow about 10 minutes for this and then open a discussion of any surprising things they have learned about their county. For example, the literacy rate in Sweden is 99 percent, while in Afghanistan it is only 36 percent. Students may also wish to speculate about reasons for more subtle differences, such as the differences in infant mortality per 1,000 births among Sweden (2.8), Canada (4.6) and the United States (6.4). Depending on the time available, you may wish to


extend this part of the activity by inviting the students to conduct additional research on their country. Knowing more about the country they represent will help them to understand the reasons behind the statistics, such as historical events (e.g., has the country been at war?), natural events (e.g., has the country experienced prolonged drought?) or the style of politics, which may account for certain aspects of the country’s situation.


4.Explain to the groups that their task will be to construct a water filter using the instructions in their package. Then give students a chance to view the materials price list and count their money. Sweden will discover that it has $1,100 — no supply out of their reach! — whereas Afghanistan


GREEN TEACHER 83 Page 31


$5/square $5/ball $10/cup $10/cup


Water, clean


Sand, coarse Sand, fine


$5 each $20/cup $20/cup $10/litre


Brazil — $200 Sudan — $50


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