feb-22-2002-geochemistry

Next: 1. From your understanding

Geochemistry
Topic: Tracking the Distribution of Persistent Organic Pollutants

Eric Thern
March 28, 2002

1. From your understanding of the reading what is a Persistent Organic Pollutant (POP)?
2. What properties do POPs have?
3. When and who suggested that POPs might migrate to, and condense at, the poles?
4. What physical properties allow POPs to migrate and partition?
5. What is the 'grasshopper' effect and how is it manifested?
6. Review Figure 2. Compare the concentration of Lindane (alpha - HCH) in ocean water between Lancaster Sound and the Java Sea. How many times more Lindane is found in the high Arctic.
7. The Lindane concentrations are measured in ng/L. What is a ng/L? Why would a concentration that small be of potential environmental concern?
8. Why might sediment cores in northern Canada show the delayed arrival of POPs in contrast to cores taken at lower latitudes?
9. Which POPs compounds are more likely to remain at lower latitudes?
10. What is the $K_{OA}$ coefficient and why is it used?
11. What form do POPs have in the atmosphere?
12. What is the $T_{C}$ and how does it determine which compounds will be transported and condensed at the poles?
13. Why are PCBs very useful in monitoring environmental partitioning processes?
14. Which PCBs are likely to be far traveled? Which are likely to remain where they were released?
15. Which PAHs are likely to be far traveled? Which are likely to remain where they were released?
16. Which pesticide is least likely to wind up in Lake Trout in the Arctic (Figure 3)?
17. Why does the geometry of the poles enhance contaminant concentrations?
18. Describe the release of a pulse of POPs at the equator and how it migrates over time (Figure 5).
19. Why might the distribution of POPs at any one instance in time be deceiving in terms of their ultimate fate?
20. Why are the contaminants deposited in the polar regions less likely to be degraded?
About this document ...

Eric Thern
2002-03-28