By:       Linda S. Burke                           

Ontonagon Elementary School

Ontonagon, MI



Teaching unit implemented November 11 –  27, 2002


THE MAD HATTER:  Mercury’s Toxic Tale


Subject:  Cross-curricular to include ecology, chemistry, health, math, social studies, and art. 


Grade Level:  sixth grade students


Purpose:  (1) To raise student awareness of the presence of mercury and other contaminants in Lake Superior, as well as what affects these contaminants have on fish, birds, game animals, and humans.  (2) To facilitate student understanding of the relationship between toxins released in our environment and toxins found in living organisms. (3) To elicit student interest and involvement in the protection of Lake Superior’s waters, along with its inhabitants.   


Overview:  Students viewed portions of Michigan at Risk videos concerning mercury contamination of the environment.  They surveyed local sports fishermen to determine their privately-held opinions regarding the seriousness of mercury contamination.  Students examined Lake Superior water quality, using a Hach test kit. Next, they learned about “bioaccumulation” by playing “Food Chain Tag.”  Students viewed a demonstration of groundwater contamination that utilized a Groundwater Kit.  Finally, students created colorful 9”x12” posters, promoting consumption advisories for sports fish.  Throughout the unit, emphasis was on students asking scientific questions, doing internet research, and exploring possible solutions as a group.    


Estimated Time Commitment:  Minimum 8 class periods;\, more time would be preferable. 




Day One

Materials:  Students needed binders with pockets to hold the handouts they received. 


Could there be more to the  “Mad Hatter” of Lewis Carroll’s Alice in Wonderland than just an amusing characterization?  In Victorian England, workers who manufactured men’s fashionable felt hats from beaver skins were known to behave erratically.  Perhaps, their mania was explained by the fact that mercury was liberally applied when processing the skins.  

Teacher introduced the unit by presenting a brief history of the six most-cited  mercury contamination incidents:  1953, Minamata, Japan where 111 people died or suffered from nervous system damage after daily consumption of mercury contaminated fish; 1965, Niigata, Japan where 120 people were poisoned after daily consumption of mercury contaminated fish;  1970, Alamogordo, New Mexico, where a farm family was poisoned by eating pork from a pig that had been fed methyl mercury treated grain; 1971-72, Iraq, where 6,530 persons were hospitalized and nearly 500 people died following consumption of bread made with grain that had been treated with methylmercury fungicide; 1980’s Quebec, Canada, where offspring of a Native American couple, subsisting on mercury-tainted fish, suffered convulsions, visual defects, blindness, severe mental/physical retardation, infant mortality, and premature death.  1995-96, Faroe Islands study of children from a fish-eating population, showed high methyl mercury exposure levels. 


ADDITIONAL TEACHING RESOURCES  Kansas Department of Health and Environment  Focus:  Environmental Health Perspectives

The Great Lakes: Environmental Atlas, USEPA, 1995, pages 30-32.


Distribute handout showing the body systems affected by mercury poisoning in both man and animals.  Waldbott, G.L. Health Effects of Environmental Pollutants,  2nd ed. St. Louis, MO, 1978 and Newman, J.R. Effects of Air Emissions on Wildlife Resources U.S. Fish and Wildlife Services Program, 1980.

            After viewing portions of Michigan at Risk videos, teacher led a classroom discussion of the following questions:

(1)    Do you think there have been other instances of mercury poisoning that were not reported?  Why? or Why not?  Possible responses might be: (a) there is a delay time for symptoms to become prevalent,  (b) communities might not understand what is happening or might not share problems, (c) developing countries might not disclose information, preferring to profit from industrial development. 

(2)    Do you think, knowing the disastrous affects of mercury poisoning, people are still                                      

stonewalling efforts to reduce mercury emissions from industry?  Teacher will relate story of

Wisconsin’s commitment ( June 2002) to cut mercury emissions by 90% over the next 15 years.  Also, relate how supervisors of Wisconsin’s state-run coal-burning power plants loudly protested the stringency of the goal.  For more information see Great Lakes Directory, 5/15/02, Craig Minowa ,



HOMEWORK ASSIGNMENT FOR DURATION OF UNIT:  Each evening students will contact one person who sport fishes in the Great Lakes.  Students will use the following form to record answers to the survey questions.  They are to make the survey experience as objective as possible by NOT commenting on the participants’ answers.  The participant is to remain anonymous.  However, students must avoid duplication by asking the person if they have already responded to this survey with another student in the class.   


Interviewer’s Name___________________________________________ Interview Date _____________




1.       What lakes or streams does the participant fish most often?


2.       How frequently do they go fishing?  Daily?                          Weekends?                   Summers only?


3.       How many years have they fished in the U.P.?


4.       What kind of fish do they like to catch?


5.       Does the participant usually eat their catch or release it?


6.       How often do they eat their catch?  Once daily?                         One meal a week?


Two meals a week?                                   Other responses ___________________________


7.       Has the participant noticed any changes in the fish over the years that they have been fishing?

a) Changes in the number of fish available?


b) Changes in the variety of fish available?


c) Changes in the size of fish they have caught?


d) Changes in the behavior of the fish they have caught?


8.       Has the participant read the state fish consumption advisories stated on the back of their fishing license?


9.       Has the participant heard about mercury contamination of Great Lakes fish?


10.   What is their personal opinion about the seriousness of the threat of mercury contamination? 

____ No truth to it!  Our lakes are too remote to get polluted.

____ Don’t know?

_____It’s a problem that can be dealt with by proper cooking methods.

_____It’s a very serious problem with no solution.  It is no longer safe to eat fish.

Additional comments______________________________________________________


11.   Is mercury contamination a real threat to anglers who fish Lake Superior?  _____ Yes         ____No


12.   Is mercury contamination a threat to anglers who fish the inland lakes of Michigan’s Upper Peninsula? __Yes   __ No





Day 2


Teacher divided the class into four research groups.  Students answered the questions on the Mercury Learning Guide by going to suggested internet sites.  One group at a time met with the teacher at the front of the class.  There, water samples taken from Lake Superior were analyzed using a Hach test kit.


 Day 3


Students continued with internet research into mercury.  When all the worksheet questions were answered, students discussed and shared their answers.  This activity was extended into the real world by reading and discussing the article,  “Should Michigan alter water, air pollution laws?”  by Rita Jack and Robert Fenech.  The Detroit News,  April 14, 2002, page 15A.  This commentary debated two views, one held by a Sierra Club director and the other held by the senior vice-president of nuclear, fossil and hydro operations for Consumers Energy in Jackson, Michigan.  Another article detailing children’s exposure to mercury was also discussed (Wisconsin Department of Natural Resources, pgs. 15, 16).


Day 4


Contaminants are measured in ‘parts per million’…For example, a scientist might say that a coho salmon has 8 parts per million of PCBs.  This would mean that if you divided the fish’s weight into a million parts, 8 of those parts would be made up of PCBs…The U.S. Food and Drug Administration sets limits on the amount of contaminants that can be in a food product to be sold.  The state public health department issues advisories for personal consumption of fish. 


Distribute worksheet with one million dots.  Have students draw a circle around those dots to represent consumption advisories for mercury levels in fish.  Draw a blue line through the middle of one dot to represent a mercury level of .16 to .65 parts per million in fish that may be eaten once a week.  Draw a orange circle around two and one-half dots to represent a mercury level of .66 to 2.8  parts per million in fish that may be eaten at one meal a month.     Draw a red circle around three dots to represent a mercury level of more than 2.8 parts per million in fish.  These fish should not be eaten.  To place this matter in perspective, have students draw a black circle around ten dots to represent the methyl mercury contamination of 10 parts per million in fish that were found responsible for Japan’s Minamata poisoning incident.   


“Most inland lakes in Michigan, northern Wisconsin, Minnesota, and Ontario have at least some species of fish with mercury levels exceeding 5 parts per million level.  Species of fish include rock bass, perch, crappie, large and small mouth bass, walleye, northern pike, and muskie.” (“Michigan Waters and Their Fish:  Are They Safe to Eat?” by Cathy D. Hoffman).  Asked students:  If this statement is accurate, should any U.P. angler eat their catch?  How does Hoffman’s statement impress you?  Would you change your fishing habits or stop fishing?

According to the U.S. Department of the Interior, “Mercury is not like PCB’s, dioxins and other contaminants.  Mercury concentrates in the muscle tissue and cannot be filleted or cooked out of game fish.”   Asked students:  Why would this make mercury a bigger problem than PCB’s which concentrate in the fat of a fish?  Answer:  Fat can be cut away before cooking fish.  Fish can be broiled to further reduce contaminants.


As a class, students computed parts per million with the formula provided in The Life of the Lakes, pg.32.  Students played “Food Chain Tag” (Great Lakes Aquarium, pg. 74-76) for the last 10 minutes of class in the gym. 




Day 5


Class divided into four groups.  Each group listed “The Ten Most Important Facts” about mercury/mercury pollution/mercury toxicity.  No more than 10 facts total were accepted from each group.  Students utilized environmental texts, EPA publications, and Internet sites to develop their list.  Twenty-five minutes were allowed for this activity. 


Students returned to the classroom mode.  Lists were discussed and compared.  How did the group decide on a particular item to include?  Were there any other items that should have been considered on the lists, but weren’t?   


Teacher put her “Top Ten” list on the overhead for comparison. Given the validity of these facts, what could students do to alter the situation?  Teacher assisted students in generating an involvement list.    


Assessment:  Teacher compared group lists to the teacher list.  Groups who matched the teacher’s list, item for item, scored higher than those who failed to recognize the significant concepts of this unit.  Of course, teachers need to use discretion and be open to student viewpoints. 


Time remaining in the hour was used by students to brainstorm ideas for  9”x 12” posters.  Posters were assessed for design and attractiveness.  Inland lakes’ anglers should be advised to catch and release. (These posters should be laminated if they are to be placed outdoors.  Ask permission of the MDNR before posting at fishing sites.)



Day 6


Teacher distributed MDNR handouts:

Contaminated landfill sites in Michigan

            Contaminated underground storage sites in Michigan

Class discussed groundwater risks in our community.  Teacher utilized the groundwater model to show how contaminants can move into streams and lakes.  Class brainstormed what could be done to reduce the mercury problem in our community. 



Day 7


Teacher tabulated the results of the fishing surveys.  Class discussed the answers given by local fishermen.  Students drew individual graphs that compared the kinds of fish caught, the number of fish caught, and the number of fish eaten.  Students then compared their survey findings to charts in  The Life of the Lakes, pgs 72 & 73.  As a class, they developed a statement that conveyed the general awareness and attitude toward mercury contamination held by fishermen living in the Lake Superior basin.               

The class began to make  9” x 12” posters to inform fishermen of the lake advisories.



Day 8


Quiz given to assess students’ knowledge and understanding.  After the quiz, students finished their posters. 






C I.1.1 Generate scientific questions about the world based on observations.

C I.1.3 Use tools and equipment appropriate to scientific investigations.

C I.1.5 Use sources of information in supporting scientific investigations.

R II 1.1 Evaluate the strengths and weaknesses of claims, arguments and data.

R II 1.5 Develop an awareness of and sensitivity to the natural world.

LEC III.5.6 Describe ways in which humans alter the environment.







Botkin, Daniel B., Keller, Edward A. Environmental  Science:  Earth As A Living Planet, John Wiley & Sons, Inc., New York, NY, 2000.                                


Bryan, Dr. Virginia, Burbank, Allen, Ballinger, Dr. Jack. Rivers Curriculum Guide: Chemistry.  Dale Seymour Publications, 1997.


Canada Today, vol 12, no.2, 1981, “How Many More Lakes Have to Die?”


Connor, J.J.  “Potential pathways for toxic elements to become concentrated in plants, animals, and humans.” U.S. Geological Survey Circular 1033, page 61.


Dann, Shari L., PhD., The Life of the Lakes:  A Guide to Great Lakes Fishery Education Materials, Michigan Sea Grant Extension, Department of Fisheries & Wildlife, Michigan State University, Lansing, Michigan


Dale Seymour Publications, “How Big Is a Million?”, Student Sheet 2, 1997.


Edelstein, Karen, Trautmann, Nancy, & Krasny, Marianne, Watershed Science for Educators, Cornell      



Great Lakes Aquarium, Lake Effects:  The Lake Superior Curriculum Guide for Grades K – 8. Duluth, MN           Pgs. 74-76.


Hoffman, Cathy D., “Michigan Waters and Their Fish:  Are They Safe to Eat?”


Jack, Rita; Fenech, Robert, “Should Michigan alter water, air pollution laws?” The Detroit News,

April 14, 2000, page 15A.                                  


Jacobson, Cliff, Water, Water Everywhere, 1991, “Water Quality Factors Reference Unit,” “Student          

Reading Unit About Water Quality,” “Teacher’s Guide and Experiments.” Hach Company. 


Monson, Bruce A., A Primer on Limnology, second edition, 6/2000.  The University of Minnesota

Extension Service, St. Paul, MN.


National Atmospheric Deposition Program/National Trends Network, 1997, “pH of precipitation over the United States in 1996.”


Newman, J.R., Effects of Air Emissions on Wildlife Resources, U.S. Fish and Wildlife Services Program. 1980. Known sites of effects of some major pollutants in wildlife.

Shaw, Byron, Mechenich, Christine, and Klessig, Lowell.  Understanding Lake Data. 2002. University of Wisconsin Extension Service, Madison, WI.


United States Environmental Protection Agency, The Great Lakes:  An Environmental Atlas and Resource Book, Third Edition 1995, Chicago, Illinois.


Waldbott, G.L.  Health Effects of Environmental Pollutants.  2nd ed. Mosby, St. Louis, MO. 1978.


Williamson, “Generalized circulation of the atmosphere,” Fundamentals of Air Pollution, 1973.




The Canadian Marketing Association,

The Complementary Medical Association,

Dartmouth College,, “Assessment Rubrics” by curriculum project for Members, “Oral Presentation”


Focus:  Environmental Health Perspectives

Great Lakes Aquatic Habitat News,

Great Lakes Directory,

Kansas Department of Health and Environment

Keweenaw Interdisciplinary Transport Experiment in Superior (KITES),                                                    

Lake Superior College, Environmental Science Department,

Lake Superior Binational Program,

Montgomery County, Maryland Department of Environmental Protection,                                       

The State of Massachusetts Department of Environmental Protection, 1996                                                

The State of Michigan Department of Environmental Quality


  ,1607,7-135-3585 4127 4175-35420—CI,00.html

**The State of Minnesota Mercury Website

The National Center for Environmental Research,                                                                                     

Pacific Northwest National Laboratory,

The State of New Jersey Department of Environmental Protection,

St. Louis River Citizens Action Committee,

Synapse, Univ. of California, San Francisco.,

UniSci Daily University Science News,

UniSci Daily University Science News, “Why Mercury Levels in Water Don’t Equal Levels in Fish”

United States Environmental Protection Agency

      click on “publications”

United States Environmental Protection Agency

University of Texas Marine Science Institute                                                                                

U.S. Department of the Interior

Wisconsin Natural Resources Magazine





 Michigan at Risk:  Betrayal of the Great Lakes,” 1991. Michigan State University, Lansing, MI.

(30 minutes) 

“Michigan at Risk:  The Not So Great Lakes,” 1991. WNMU-TV, Marquette, MI. (30 minutes)     

“Poisoning the Circle:  Mercury In Our Ecosystem,” 1993. Great Lakes Indian Fish and Wildlife Commission, Odanah, WI  (12 minutes)




Groundwater Model and Educational Materials from Western U.P. Center for Science, Mathematics & Environmental Education, 105 Dillman Hall, Michigan Technological University, 1400 Townsend, Houghton, MI  49931.


Hach Test Kit and resources.  Water, Water Everywhere Educational Lab books (especially “Water Quality Factors” ).