1. You need to make predictions on how each part of the food web would be affected by the spraying of DDT. These are to be predictions. It is highly doubtful you will get all of the predictions correct without doing research. Please make sure to address all parts of the food web pictured.
In the 1950's, the island country Borneo had a severe problem with malaria, which is carried by mosquitoes. The World Health Organization (WHO) decided to spray a pesticide called DDT to rid the island of mosquitoes. The accompanying diagram (click the other link titled Food Web and DDT) shows a simplified food web of the ecosystem including the organisms affected by the DDT.
- DDT causes nerve damage, slow reflexes, and eventual death in human and other animals.
- When an animal consumes another animal that has consumed DDT, the consumer is also affected by the DDT.
- DDT kills mosquitoes; it also affects cockroaches but does not kill them.
Once you have made your predictions, researched the actual events that took place involving the spraying of DDT on the island of Borneo. For each part of the food web, look at your submitted predictions and discuss if you were correct or incorrect.
Second, research and propose two "greener" solutions to the original problem of mosquitoes. A link has been provided in this folder to use to begin the assignment, but it should not be your only resource. Be sure you explain the solution completely, and discuss whether it will have any affect on the other parts of the given food web.
Ecology- DDT affect on the food web
With DTT in the Borneo web, one might focus first on the cockroach. Since the agent kills the mosquito but not the cockroach, special attention should be given to where it goes AND DOES. The insect can store the toxic element. DTT could be on the surface, where it walks and be transferred to regions where humans have activity, as well as the cat, rat or flea. All the creatures on the said web could be affected simply by picking up residue left on surfaces or by what the cockroach has left behind, even with the mosquito dead and no longer available for consumption.
There are no birds indicated on this web but any observer might suspect the infected caterpillar, migration to thatched roof could be vulnerable, as well as birds that might eat it. That insect could be affected merely by spray on the roof and by consuming the roof contents or by walking on other areas in the region. However, more relevant to the story here is the fact ...
In about 600 words, this solution provides a discussion on the contaminant DDT and the influence that this toxin has on food web structure.
guide with article critiuque on WHO's position on the use of DDT in malaria vector control
The use of DDT has been banned in the United States because of environmental damage and human health concerns. However, in malaria-plagued countries such as Africa, the World Health Organization approves the use of DDT for indoor residual house spraying. Read the following WHO's Position Statement, "The use of DDT in malaria vector control".
Link to: WHO's Position Statement on DDT
Take the position that you work for the World Health Organization, and have been tasked with re-evaluating the current policies outlined in their Position Statement. The following questions and instructions will guide you in your analysis, but feel free to use other information and avenues of investigation to critically analyze this policy.
1. How would you use a risk versus benefit assessment, and what other types of toxicology data would you need to make this decision? Refer to Chapter 12.
2. Use the four phases of the disposition of a toxic compound to assess the toxicity of DDT.
3. What types of exposure and response are associated with DDT?
4. Should the WHO continue to approve the use of DDT to combat malaria?
Global Malaria Programme
The use of DDT in malaria vector control
WHO position statement
World Health Organization, 2011