March, 13 2012
Pesticides and Food: Some Issues
-“safe” levels for only 100 of 250-300 base chemicals
-the breakdown problem: the case of Alar
-combined or “synergistic” effects?
-Synergistic effect is the effect that these pesticides do to the products they are used on
-many consider the organic option [has substantial lower rates of pesticide use]
-what about banned/unregistered pesticides we eat on imports?
-but aren’t those natural toxins much worse?
-Aflotoxins in nuts [essentially mold]
-carcinogens in burned meat
-who else is at risk: farmers and farm workers
-farmers can have higher rates of certain cancers [due to the diff. pesticides they use]
-food outside our boarders, produced by farm workers [heavy use of migrant labour]
-some good news:
-Sweden, Norway, Denmark & prov. Of Ontario have reduced pesticide use between 50-75% in recent
The Land Ethic: Aldo Leopold 1887-1948
-the story of Odysseus: What is L.’s message?
-how is land like the slave girls?
-Privilege but not obligation
-what is an ethic? For L. it’s a “differentiation of social from anti-social conduct”
-the single premise of ethics: the individual is a member of community w/interdependent parts
-what would a land ethic do?
-change role of Homo sapiens from conqueror [anthropocentric view] to plain member of a wider
-“the problem we face is the extension of the social conscience from people to land”. Land must become
valuable in its own right
-ecological history: wrecked landscapes and ecological succession. [Had no ethics for the land, didn’t
care what happened to it]
-what is wrong w/conservation based on economic self-interest?
-> assuming the “economic” parts of the biotic clock function w/out the non-economic parts. Keystone
species: species that exert some kind of controlling influence. I.e. the sea otter [help regulate their
ecosystem by regulating sea urchins population]
-The Land Pyramid: a succession of biotic layers, each dependent on the one below -> i.e. food chains
-the lower levels numerically greater than higher layers
-land as a “fountain of energy” -> energy flows through circuits of soils, plants, animals -> food chains
conduct energy upwards, followed by decay and return of energy to the soil
-conventional agriculture may derange energy flow and/or deplete storage in the soil
-aquifer depletion via irrigation; continual monocropping; poor cultivation practices->soil loss, soil
-“land is a community, is a basic concept of ecology, but that land it to be loved and respected is an