Lesson plan
Dieldrin
Dieldrin is an organochlorine compound originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels–Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene. Originally developed in the 1940s as an alternative to DDT, dieldrin proved to be a highly effective insecticide and was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of dieldrin. When concerns started to be raised into the safety of Dieldrin in the 1960s, the leading manufacturer, Shell Chemicals, conducted in house research to prove its safety. Conducted at Shell's Tunstall Laboratory, in Sittingbourne in southern England, thirteen volunteers were subjected to up to ten times the amount of Dieldrin found in farmed food, and Shell reported 'no apparent effect on their health.' However, independent research has shown it is an extremely persistent organic pollutant; it does not easily break down. Furthermore, it tends to biomagnify as it is passed along the food chain. Long-term exposure has proven toxic to a very wide range of animals including humans, far greater than to the original insect targets.…
Article summary
Dieldrin is an organochlorine compound originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels–Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene. Originally developed in the 1940s as an alternative to DDT, dieldrin proved to be a highly effective insecticide and was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of dieldrin. When concerns started to be raised into the safety of Dieldrin in the 1960s, the leading manufacturer, Shell Chemicals, conducted in house research to prove its safety. Conducted at Shell's Tunstall Laboratory, in Sittingbourne in southern England, thirteen volunteers were subjected to up to ten times the amount of Dieldrin found in farmed food, and Shell reported 'no apparent effect on their health.' However, independent research has shown it is an extremely persistent organic pollutant; it does not easily break down. Furthermore, it tends to biomagnify as it is passed along the food chain. Long-term exposure has proven toxic to a very wide range of animals including humans, far greater than to the original insect targets.…
Key claims
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.