Chapter 5 - Supplemental II Flashcards
chemicals that dissolve other substances
solvents
petroleum refineries, chemical industry degreasing metals in electronic industries, dry cleaning textiles
Cleaning synthesizing chemicals
Most organic solvents affect the ____ mainly causes damage to the ____. Can also cause cancer: non-chlorinated, chlorinated
central nervous system (CNS)
liver and kidney
What affects does BTEX have on the body?
- dizziness
- unconsciousness
- anemia
- leukemia./CNS damage
- eye and throats irritation
- headaches
List some non-chlorinated solvents.
- benzene
- toulene
- ethylbenzene
- xylene
List some chlorinated solvents.
- TCE
- PCE
- TCA
____ pollution in groundwater is a worldwide problem that can result in uptake and accumulation of toxic chemicals in food chains and harm the species circulation of affected habitats. Leaks are estimated to occur at 1/3 of all underground motor fuel storage facilities, causing significant groundwater contamination.
BTEX
Which two factors are biodegraded by sorption?
environmental and chemical
Microbial Detoxification of BTEX Under Aerobic Conditions
Benzene
inserts 2 hydroxyl groups (benzene dioxygenase)
benzene-cis-glycol
TCA cycle
Microbial Detoxification of BTEX Under Aerobic Conditions
Tolene
Inserts 1 hydroxyl group (tolene oxygenate)
benzyl alcohol
TCA cycle
Microbial Detoxification of BTEX Under Aerobic Conditions
M-eylene
inserts 1 hydroxyl group (xylene oxidase)
3-methyl benzyl alcohol
TCA cycle
What are the two metabolites of PCE?
- trans-1,2-dichloroethylene (DCE)
- vinyl chloride (VC)
What is special about the metabolites created from PCE?
they are more toxic than the parent compound due to microbial degradation
What is the path of microbial degradation of PCE?
TCE > trans-1,2-DCE > VC
Chlorinated solvents can be degraded by abiotic and microbial reactions into what terminal products?
- CO2
- H2O
What is the major pathway of TCE and by what process?
TCE > DCE (isotopes) > VC > ethylene
hydrogenolysis
How is PCA transformed into TCE?
dehydrochlorination
What is the pathway of transformation of PCA?
PCA > 112 TCA > 12DCA > chloroethane > ethane
How is PCA transformed into cis-12DCE and trans-12DCE?
dichloroelimination
How is 112TCA transformed into VC?
dichloroelimination
Dehydrochlorination of tetrachloroethane will lead to…
a) trichloroethane
b) DCE
c) VC
d) trichloroethylene
d) trichloroethylene
chemicals used to make plastics plastic
phthalate plasticizers
What chemical is present in some plastic products?
bisphenol A
What does the phthalate family include?
- DEHP
- DINP
- DBP, DEP, DMP
What problems do phthalate plasticizers and disphenol A induce in the body?
endocrine distruption
any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating pests. Pests can be insects, rodents, weeds, and a host of other unwanted organisms
pesticides
a pesticide compound specifically used to kill or
prevent the growth of insects
insecticide
a chemical pesticide designed to control or destroy plants, weeds, or grasses
Herbicide
a pesticide that is used to control, deter, or destroy fungi
fungicide
chemical agent that is destructive to nematodes
nematocide
chemical or agent used to destroy rats or other
rodent pests, or to prevent them from damaging food, crops, etc
rodentocide
What is the most prominently used ingredient in pesticides?
glyphosate
herbicide
What are the major classes of pesticides and insecticides?
- organophosphates (OP)
- organocarbamates (carbamates)
- organochlorides
- pyrethroids
Most persistent pesticides are those that
have complex structures including ____ and multiple ____ groups attached to
them.
aromatic rings; halogen
an enzyme found primarily at nerve endings that catalyzes the hydrolysis of acetylcholine into acetic acid and choline
cholinesterase
What are the acute effects of organophospahte poisoning?
anticholinesterase activity happens soon after exposure and causes impairment of the neural impulse transfer mechanism
What are the long term effects of organophospahte poisoning?
- organophosphate-induced delayed polyneuropathy
- numbness, loss of sensory abilities, weakness
What are some examples of organophosphates?
- diazinon
- malathion
- methyl parathion
- parathion
Where do organophosphates appear?
sprays, baits, indoor foggers and bombs, flea collars, pet shampoos, powders, animal dips, and
granules
Which organophosphate has been approved for direct application to food crops such as fruits, row crops, and vegetables?
malathion
Name the organophospahte
- Degrades rapidly by hydrolysis, biodegradation, and photolysis
- Found in surface waters
- Rapidly absorbed, transformed, and excreted if
ingested
malathion
What can malathion be degraded to?
succinate
Name the organophosphate
- Close relatives of the organophosphate
pesticides - Dissipate quickly from the environment as a
result of breaking down into other substances - Some are approved for controlling garden
pests (e.g., wasps, hornets, and snails). - An ingredient in some products applied to
furry pets to control ticks and fleas
carbamates
What are some examples of carbamates?
- carbaryl (Sevin)
- aldicarb
- fenoxycarb
- propoxur
- metam sodium
an intermediate
chemical used for the manufacture of
carbamate pesticides
methyl isocyanate (MIC)
What are the acute effects of exposure to MIC?
extremely toxic to life forms
What chemical was accidentally released in India in 1984 that killed more than 3,800 people?
methyl isocyanate (MIC)
What are the toxic products of microbial degradation of carbamates?
- 5-hydroxy carbaryl
- 5-hydroxy propxur
- methiocarb sulfoxide
- aldicarb sulfoxide
Derived from chlorinated hydrocarbons,
which are chemical compounds that contains
chlorine, carbon, and hydrogen
organochlorines
- Characteristically stable and fat-soluble;
persist in the environment and bioaccumulate
in the food chain - Associated with suppression of the immune
system and cancer
organochlorines
What are some examples of organochlorine pesticides?
- DDT
- Lindane
- Chlordane
- Mirex
- Hexachlorobenzene
- Methoxychlor
What are some examples of herbicides and defoliants?
- atrazine
- simazine
- paraquat
- 2,4-D
- 2,4,5-T
What unstable compound is a product of the microbial degradation of simazine?
cyanuric acid
- Derived from natural sources–certain
varieties of chrysanthemum flowers - Have great ability to paralyze and kill flying
insects - Interfere with transmission of neural impulses
via action on sodium channels
pyrethrins
What molecular pathways does pyrethrins interfere with?
transmission of neural impulses via action on sodium channels
What are some examples of industrial organic contaminants?
- petroleum hydrocarbons
- perchlorate
- PCBs
- PCDDs
Which of the following elements are not found in Malathion?
a) H
b) C
c) O
d) Cl
c) S
d) chloride (Cl)
What are the different mechanisms of microbial degradation of carbamates?
- dealkylation (N and O)
- hydroxylation
- sulfoxidation —> hydroxylation: N-methyl
Microbial Detoxification of 2,4-D
The intermediate is ____ which is broken into two different pathways. The difference between the two is where the ring is broken
4-Chlorocatechol
A total of ____ compounds in the dioxin family are known to exist.
419
What human activities produce dioxins?
- Incineration of industrial and municipal wastes
- Burning of some fuels
- Bleaching of wood pulp for paper manufacturing process
- Manufacture and application of some
herbicides such as 2,4-Dichlorophenoxyacetic acid; 2,4,5-Trichlorophenoxyacetic acid,etc.
What are the health effects of exposure to dioxine?
- Chloracne
- Skin rashes
- Skin discoloration
- Growth of excessive body hair
- Liver damage
- Possible cancer risks
- Endocrine effects
- Reproductive and developmental effects
Composed of condensed aromatic rings with 1-8 chlorine substituents
PCDD
Sometimes ____ (and its metabolites) is called an endocrine disruptor, meaning that it acts as an antagonist to androgen
DDT
What is an estrogen-mimicking compound in plants?
phytoestrogens
What is an estrogen-mimicking compound in fungi?
mycoestrogens
What is an estrogen-mimicking compound in humans?
xenoestrogens
____ have been shown to accelerate the
growth of neoplastic cells, especially in the breasts.
- Most important compounds are known as flavonoids
- They give flowers their distinct color
phytoestrogens
What are the most important compounds of phytoestrogens?
flavonoids
What are some serious health problems which are associated with xenoestrogens?
- birth defects
- sterility in men
- cancer
- immunosuppression
