Q 1: chapter 2

Question 1

when was there an enormous increase in the use of chemicals in agriculture, industrial manufacturing, and around the home

Answer 1

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

Question 2

how does mercury and lead affect humans

Answer 2

developmental effects, harming the developing nervous system for a lifetime

Question 3

how do chemicals contribute to their toxicity to humans and other species

Answer 3

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

Question 4

what was done to address the public and environmental health concerns caused by these and other compound

Answer 4

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

Question 5

what is the tsca, when was it passed

Answer 5

US Toxic Substances Control Act, 1976 but has been largely ineffective for chemical management.

Question 6

what is the FQPA and when was it passed

Answer 6

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

Question 7

what is the UNEP

Answer 7

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

Question 8

what are PBT

Answer 8

Persistent Bioaccumulative and Toxic

Question 9

what does exposure depend on

Answer 9

s location, diet, housing, occupation, and socioeconomic issues

Question 10

what is IPM

Answer 10

. 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.

Question 11

What is the Lindane Dump Site?

Answer 11

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).

Question 12

dioxin

Answer 12

Extremely Toxic – dose makes the poison (DMTP)
Extremely Expensive to clean up
Extremely Low Concentrations - DMTP

Question 13

are dioxins persistant

Answer 13

yes they will stay for decades- MAN MADE

Question 14

what is dioxins LD-50

Answer 14

0.001

Question 15

where are dioxins found in our food

Answer 15

dairy, meat,fish, fatty foods

Question 16

what does PCDD

Answer 16

POLYCHLORINATEd-p-dioxins

Question 17

what does PCDFs

Answer 17

polychlorinated dibenzoFURAN

Question 18

In what family does dioxins and furan belong to

Answer 18

halogenated aromatic compounds

Question 19

how many isomers do dioxins have

Answer 19

75

Question 20

how many isomers do furans have

Answer 20

135

Question 21

how many chlorines do dioxins and furans have

Answer 21

1-8

Question 22

which has a single oxygen bridge- dioxins or furans

Answer 22

furans

Question 23

which is the most toxic of the dioxins

Answer 23

TCDD-2,3,7,8-tetrachlorodibenzo-p-dioxin

Question 24

how do you mesure a PCDD/Fs potency

Answer 24

it is additive

Question 25

how are dioxins mesured

Answer 25

parts per trillion- aka picogram (pg)/g

Question 26

when did we find about dioxins

Answer 26

1970Saw effects but didn’t know the cause
Could not even measure until the late 1970’s
Accurate techniques for low ppt analysis not available until the late 1980s

Question 27

what is the difference btw urban and rural air in terms of dioxins

Answer 27

1-50pg/m3 vs.

Question 28

where are dioxins most common

Answer 28

in sediment- acts like fat

Question 29

Symptoms of dioxins found in what animals?

Answer 29

Trout and Great lake fish eating birds.

Question 30

Viktor Yushchenko

Answer 30

Very likely poisoned by TCDD: Blood levels were 50,000 times higher then normal population.`

Question 31

Toxic responces to dioxin?

Answer 31

Wasting syndrome: weight loss not related to food consumption
Skin: acneform eruptions (chloracne), edema, hyperkeratosis
Hyperplasia of extrahepatic bile duct, gall bladder & urinary tract
Lymphoid involution; thymic/spleenic atrophy
- immunesuppression
Liver damage: necrosis, tumors
Porphyria: disordered porphyrin metabolism (skin blistering/fragility)
Endocrine and reproductive dysfunction
Teratogenesis (deformities and birth defects)
Carcinogenesis: e.g., hepatocarcinoma
Highly species dependent – similar species can be 1,000s of times more or less sensitive

Question 32

Sources of PCDD /f’s

Answer 32

Unwanted by-products of chemical processes (any combustion process with chlorine present)
Industrial sources associated with the production of chlorinated phenols (e.g., pentachlorophenol), phenoxy herbicides (e.g., 2,4-D, 2,4,5-T)
Pulp and paper industry, metallurgical processes, chlor-alkali process
Municipal, hospital and industrial waste incinerators - fly ash, Sewage sludge, automobile exhaust (largest source ? ?)

Question 33

Times Beach Missouri

Answer 33

Town completely evacuated because of dioxin contamination.

Due to a dust problem in the 1970s 23 miles (37km) of dirt roads in the ‘city’ of Times Beach, Russell Bliss was contracted to oil roads.
From 1972 to 1976, Bliss sprayed waste oil on the roads for 6c /gal.
Bliss contracted with a company called IPC to dispose of toxic waste. IPC was paid $3,000/ load to remove toxic waste fromNortheastern Pharmaceutical and Chemical Company(NEPACCO)
IPC in turn paid Bliss $125 to ‘eliminate’ the waste. NEPACCO producedhexachlorophene from 2,4,5-TCP, inVerona, MO
Bliss claimed he was unaware that the waste contained dioxin, having even sprayed it around his own home

Times Beach (population 2,800) covered 8 square miles on the floodplain of the Meramec River in St. Louis County, Missouri
In Nov-Dec 1982, EPA sampled the roads in Times Beach. Soon afterward, the Meramec River flooded the City.
EPA rushed the analyses and found dioxin

Question 34

2,4,5-T

Answer 34

If it isn’t created responsibly it can turn into dioxins. Responsible for Times Beach

Question 35

In Vietnam how much of the TCDD reached the ground and what happened to the amount that didnt?

Answer 35

less then 5% reached the ground and the other 95% landed in the canopy’s which allowed the light to degrade it(half life 6 hours)

Question 36

What degrades TCDD?

Answer 36

UV light.

Question 37

Tolerability level for us Canadians?

Answer 37

In Canada the “tolerable” level (meaning no serious health effects are expected) is 70 pg/kg body weight/month. This is about 2.3 pg/kg body weight/day
“Studies done between 1998 and 1999 in two Canadian cities showed that the average dietary intake of dioxins, was 0.62 pg/kg body weight/day. This is well within the level considered tolerable by Joint Expert Committee on Food Additives”
See “It’s Your Health” from Health Canada – posted on BlackBoard