Arsenic Contamination: Natural Disaster or Human Induced?
Author: Sylvia Kniest

Time: 2 - 3 class periods
Copy article: “Arsenic in Drinking Water
Copy the activity guidelines
Copy format for formal letter (optional)
Materials: Article: “Arsenic in Drinking Water
Activity guidelines: “Arsenic Case Study”


Arsenic is a naturally occurring substance that contaminates the water supply of various regions in the world. The main source of arsenic in drinking water is arsenic rich rocks through which arsenic is filtered. It may also occur due to mining activity or industry. By studying the water supply in different regions students will discern whether the major cause of arsenic contamination is human caused or natural. In this lesson, students will assume the role of a member of the World Health Organization whose primary concern is to ensure that people have a supply of clean water.

Students will be able to:
1. List as a class the sources of arsenic contamination of water.
2. Describe the major health effects of arsenic contamination in a letter.
3. Identify the regions that are affected by arsenic contamination in a letter.
4. Compare human and natural causes of arsenic contamination in a class discussion.

National Geography Standard
All students should

  • Understand how human actions modify the physical environment.
  • Understand how physical systems affect human systems.
  • Understand the changes that occur in the meaning, use, distribution, and importance of resources.

NSS-G.K-12.4 Human Systems

  • Understand how the forces of cooperation and conflict among people influence the division and control of Earth's surface.

Teacher Background
The concept of arsenic contamination was introduced in the lesson; “Post Cards from the Rim”. If the teacher uses this lesson in sequence, the students need not read the introductory article. Instead, the teacher may want to review the major points through the discussion questions; for more information about Arsenic link to the background page.

Related and Resource Websites

http://www.who.int/mediacentre/factsheets/fs210/en/ World Health Organization: Arsenic in Drinking Water
http://phys4.harvard.edu/%7Ewilson/arsenic/countries/arsenic_project_countries.html Arsenic Project
http://www.bgs.ac.uk/arsenic/home.html Arsenic contamination of Groundwater
http://www.acdis.uiuc.edu/Research/OPs/Moinuddin/contents/part4.html Arsenic in Groundwater around the World
http://yubanet.com/artman/publish/printer_21518.shtml Arsenic: In Search of an Antidote to a Global Poison
Format for business letter




  • Tell students that people are exposed to hazards that they may not be aware of (unlike natural disasters studied in the previous lesson); for example, we all assume that the water we use for drinking and cooking is uncontaminated. There are people in many regions of the world, including parts of the United States, who are exposed to water that is not pure or uncontaminated. One of those contaminants is Arsenic. Arsenic in drinking water has become a global problem.
  • Hand out the Article, “Arsenic in Drinking Water” from the World Health Organization, http://www.who.int/mediacentre/factsheets/fs210/en/
    Ask students to read the sections ‘Source’ and ‘Effects’
    Hold a class discussion and list the students’ responses on the board.
    1. How does arsenic contaminate drinking water?
    2. What are the health effects of arsenic contamination?
    At the end of the discussion tell students that they will work in the computer lab to investigate specific cases where arsenic contamination is a problem.

Activity (Computer Lab):
Hand out the scenario and instructions to the students (Appendix A):

Arsenic Case Study- Student Guidelines
The 3rd World Water Forum met recently in Kyoto, Japan to discuss the problem of arsenic contamination of drinking water. Participants agree that it has become a serious challenge for people living in various parts of Asia as well as Latin America. According to experts, “the estimated number of people drinking arsenic-contaminated groundwater is of astonishing proportions; conservative estimates put the total number at greater than 50 million in the Asian region alone”. (The 3rd World Water Forum) Naturally-occurring and human-induced arsenic pollution in drinking water has been discovered in many parts of the world making this a global issue.

As a member of the World Health Organization, your task is to ensure that clean, arsenic-free water is available to everyone. Your years of experience have taught you that access to safe water is a complicated issue that affects people’s health, food supplies, living conditions, businesses and incomes. In order to complete your task, you will need to investigate the regions of the world that are known to have arsenic in their water supplies. In your investigation you will determine how the arsenic got into the water and the impact that it has had on the health of the residents in the area. As you visit the affected regions, gather information that can be used to persuade the United Nations to consider holding a Global UN Conference on the Arsenic Crisis.

Begin your investigation by looking at the following sites:

Answer the following questions as you research the sites:
1. List the specific source of arsenic contamination in each of the affected areas.

2. Was the source of contamination human-induced or natural? Explain.
b) If the source was human-induced, who should be held responsible?

3. What impact does this issue have on the residents in the area? Are there other sources of water? Is climate a factor?

4. What dietary concerns might the residents have to deal with if their supply of clean water is limited?

5. List examples of specific health issues related to arsenic poisoning.

  • Once you have completed your research you will use the information you gathered for questions 1 – 5 to write a formal letter to the United Nations Secretary General asking for a special conference on the global arsenic crisis. Begin your letter by stating the problem and your recommendations to the United Nations. Include supporting details from your research in the main body of the letter.

Follow the format for a business letter at: http://grossmont.gcccd.cc.ca.us/sandia.tuttle/businessletter.html


  • Ask for student volunteers to read their letters to the class.
  • Afterwards ask the students:

1. What were the common arguments made in favor of holding a conference on arsenic contamination?

2. What were the common recommendations?

3. Do you think that this a critical issue that the United Nations should address? Why or why not?

Formal letters to the Secretary General of the United Nations.

Embedded Assessment
Student responses to the first set of questions allow for assessment of whether they can identify sources of arsenic contamination of water, and the health impacts of drinking arsenic contaminated water.

The letter allows for assessment of students’ ability to articulate in a written form a larger concept about the global nature of this public health issue. Letters will be evaluated on content and format.


PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:

NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award


Supported by NIEHS grant # ES06694

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Last update: November 10, 2009
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