Q 1: chapter 2 Flashcards
when was there an enormous increase in the use of chemicals in agriculture, industrial manufacturing, and around the home
during the 1950s and 1960
example: We powdered our bodies with DDT to remove lice and spread DDT far and wide to control mosquitoes. We used other pesticides to kill insects and control weeds in an effort to improve crop yields. Lead was added to gasoline to make cars run better and added to house paint to make it last longer. At the same time we took advantage of the more sinister qualities of lead when we combined it with arsenic to spray on fruit trees to control pests. Pulp and paper mills used mercury to control fungi and molds to ensure that our paper remained white. Seeds were coated with mercury to stop soil fungi. Thermometers, thermostats, and switches brought mercury into everyone’s home and school
how does mercury and lead affect humans
developmental effects, harming the developing nervous system for a lifetime
how do chemicals contribute to their toxicity to humans and other species
1: they are persistent- dont breakdown in the environment or very slow so the amount is continuously rising
2: pesticides didnt only kill their intended target
3: bioaccumulate or concentrate in species as they move up the food chain- lead accumulates in bone and methylmercury in muscle
4: because of their persistence in the environment and accumulation in various species, the persistent toxicants spread around the world, even to places that never used them
what was done to address the public and environmental health concerns caused by these and other compound
government agencies have initiated various programs and regulations to control or restrict the use of the offending substances. Laws were passed to ensure more rigorous testing of compounds before widespread use, although this was not entirely effectiv
what is the tsca, when was it passed
US Toxic Substances Control Act, 1976 but has been largely ineffective for chemical management.
what is the FQPA and when was it passed
US Food Quality Protection Act (FQPA) of 1996. it was more effective in implementing pesticide testing requirements. Researchers worked to develop new pesticides and other agents that were more specific in their toxicity and much less persistent. The use of many of the persistent chemical pesticides was restricted or even banned in some places. Individual countries are responsible for regulations, so there are some countries that still use pesticides that are banned elsewhere
what is the UNEP
was more effective in implementing pesticide testing requirements. Researchers worked to develop new pesticides and other agents that were more specific in their toxicity and much less persistent. The use of many of the persistent chemical pesticides was restricted or even banned in some places. Individual countries are responsible for regulations, so there are some countries that still use pesticides that are banned elsewhere
what are PBT
Persistent Bioaccumulative and Toxic
what does exposure depend on
s location, diet, housing, occupation, and socioeconomic issues
what is IPM
. Integrated Pest Management (IPM, see definition below) is an approach to pest control that can significantly reduce pesticide use while still providing adequate or even improved results. IPM programs are used in agriculture, landscaping, and indoor pest control. Typically, IPM programs maximize prevention of pest problems through nonchemical methods, and chemicals, when used, are selected for minimum risk to nontarget species.
What is the Lindane Dump Site?
Used as a pesticide for many years this persistant agent is still used today in the elimination of fleas and nats. Industrial dumpsites such as the one in Allegheny County, Pennsylvania contain an estimated 400 tons of lindane waste and other waste dumped over a 50-year period on 30 acres of land. The runoff from this site as well as others have the potential to contaminate drinking water with lindane. Lindane is regularly detected in surface water in the United States (see US Geological Survey monitoring studies).
dioxin
Extremely Toxic – dose makes the poison (DMTP)
Extremely Expensive to clean up
Extremely Low Concentrations - DMTP
are dioxins persistant
yes they will stay for decades- MAN MADE
what is dioxins LD-50
0.001
where are dioxins found in our food
dairy, meat,fish, fatty foods
what does PCDD
POLYCHLORINATEd-p-dioxins
what does PCDFs
polychlorinated dibenzoFURAN
In what family does dioxins and furan belong to
halogenated aromatic compounds
how many isomers do dioxins have
75
how many isomers do furans have
135
how many chlorines do dioxins and furans have
1-8
which has a single oxygen bridge- dioxins or furans
furans
which is the most toxic of the dioxins
TCDD-2,3,7,8-tetrachlorodibenzo-p-dioxin
how do you mesure a PCDD/Fs potency
it is additive
