Cameo

PCBs in the Last Frontier by Michael Tessmer

Part II—Global Transport

Later studies showed that the global circulation of PCBs was at least in part due to atmospheric transport. PCBs enter the atmosphere by several mechanisms including the burning of organic material and evaporation in warmer climates followed by condensation at higher latitudes. This explained how chemicals made by humans could be found in areas untouched by humans.

Questions

  1. Come up with a hypothesis or “explanatory story” to answer the following question: Should PCB levels differ significantly in Alaskan lakes that are near each other and at the same altitude? (Keep in mind that a hypothesis is an educated guess, so it requires a reason why you think your answer is correct.)
  2. Propose a method, either through observations or direct experimentation, which would test your hypothesis from Question 1.

Go to Part III—“Significant Difference?”


Originally published at http://www.sciencecases.org/last_frontier/last_frontier2.asp

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