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Pollution - Elective > Lecture 3 > Flashcards

Lecture 3 Flashcards

1
Q

Ecotoxicology = ___________ + ____________

A

Ecology + Toxicology

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2
Q

Define ecotoxicology:

A

Branch of toxicology concerned with the study of toxic effects, caused by natural and synthetic pollutants, to the constituents of ecosystems - animals (including humans), vegetable, microbial - in an integrated context

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3
Q

The study of harmful effects of chemicals on ecosystems =

A

ecotoxicology

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4
Q

Substance present in greater than natural concentration as a result of human activity =

A

contaminant

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5
Q

Substance that occurs in the environment at least in part of human activity and which has a deleterious effect on living organisms =

A

pollutant

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6
Q

Foreign chemical not produced in nature and not considered a constitutive component of a biological system =

A

xenobiotic

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7
Q

Processes at one level take their mechanisms from the level below and find their consequences to the level above =

A

SCALES

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8
Q

SETAC:

A

Society of environmental toxicology and chemistry

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9
Q

Give me some characteristics of legacy pollutants - ORGANICS

A
  • Contain carbon and more than 1 C-H covalent bond
  • C-H = low polarity, low water solubility
  • Behaviour (fate/toxicity) dependent upon structure (size, shape, functional groups)
  • Natural or anthropogenic sources
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10
Q

PAHs =

A

Polycyclic Aromatic Hydrocarbons (PAHs)

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11
Q

T or F: PAHs are natural chemicals that are present every time you burn something

A

T

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12
Q

Describe some characteristics of PAHs:

A
  • 2+ fused benzene rings
  • decomposition, pyrolysis reactions
  • exist as complex mixtures
  • persistent (years to decades)
  • natural and anthropogenic sources but mainly anthropogenic
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13
Q

Benzo(a)pyrene is a ____

A

PAHs

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14
Q

Name 3 natural sources of PAHs

A

1) Wildfires
2) Oil underground
3) Volcanoes

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15
Q

Name 3 anthropogenic sources of PAHs

A

1) Burning trash
2) Deforestation (burn wood)
3) War, terrorism, vandalism, theft

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16
Q

PAH fate: with an increased molecular weight the following occurs:

_________________ volatilization
_______________ bioaccumulation
________________ absorption to particles
_________________ solubility (increased Kow)
________________ environmental persistence

A
  • decreased
  • increased
  • increased
  • decreased
  • increased
17
Q

What are some biological fates of PAHs in land (3)

A
  • degradation by soil microbes
  • metabolism by plants
  • metabolism by soil invertebrates
18
Q

What are some biological fates of PAHs in water (3)

A
  • degradation by microbes in water and sediment
  • metabolism by algae
  • metabolism by zooplankton, fish, mammals, and birds
19
Q

Physical effects of PAHs include:

A

smothering, reduced light (penetration will impact photosynthesis)

20
Q

Habitat change effects of PAHs:

A
  • alter pH
  • decrease oxygen
  • decrease food availability
21
Q

Toxicity effects of PAHs:

A
  • mainly on cellular membranes and enzyme-bound membranes (easily bind to lipids and penetrate the cells)
  • metabolized PAHs are reactive, bind DNA and cause carcinogenesis
22
Q

PCBs =

A

POLYCHLORINATED BIPHENYLS *2 benzene rings not fused together

23
Q

Name some PCB industrial use:

A
  • dielectric fluids in transformers and capacitors
  • coolant
  • lubricant
  • PVC in electrical wires
  • caulking sealant
  • wood floor polish
24
Q

Name some PCB properties

A
  • low water solubility (high in solvents/fats)
  • low vapor pressure
  • high dielectric constant
  • high flashpoint

*chlorination impacts physical properties (increased chlorination = increased lipophilicity and reduced vapor pressure)

25
Q

What is the trade mark name for PCBs?

A

Aroclors

26
Q

T or F: PCBs bioaccumulate up food chains in fatty tissues; fatty-fish consumers are most at risk

A

T

27
Q

T or F: PCBs are persistent, resist breakdown; cycle between air, water and soil

A

T

28
Q

T or F: PCBs are considered a PBT substance

A

T persistent, bioaccumulative and toxic

29
Q

______ are chemical substances that persist in the environment, bioaccumulate through the food web, and pose a risk of causing adverse effects to human health and the environment

A

POPs

30
Q

Organophosphate insecticides are derivatives of _______________

A

orthophosphoric acid

31
Q

Organophosphate insecticides were initially developed as ___________

A

nerve gas agents to paralyze and kill people

32
Q

T or F: Organophosphate insecticides have a higher water solubility than PCBs, PAHs, etc

A

T

33
Q

Can organophosphate insecticides be considered DDT alternatives ?

A

Yes because the 1/2 life is shorter, days to weeks

34
Q

What is the mechanism of action of organophosphate insecticides?

A

They inhibit acetylcholinesterase activity which blocks acetylcholine metabolism which then causes muscular rigidity/paralysis in insects

Pollution - Elective (19 decks)

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