Bio 346 - Freshwater Eco. (Chpt 28) --> Contaminants

Question 1

What are 4 common contaminants?

Answer 1

1. H+
2. SOx
3. NOx
4. Al

Question 2

What are the principle environmental issues in limnology?

Answer 2

Toxic chemicals

Question 3

What 2 practices can better reserve eutrophication?

Answer 3

1. Better waste water treatment

2. Better agriculture practices

Question 4

Many contaminants come from where?

Answer 4

Industrial processes

- Some are produced in nature during degradation

Question 5

What are 3 chemicals that have great concern?

Answer 5

1. Fungicides
2. Insecticides
3. Herbicides
   - Which are all used in the production of human food

Question 6

Negative effects of chemicals on…

Answer 6

1. Specie diversity
2. Community structure
3. Human health

Question 7

What does POPs stand for?

Answer 7

Persistent organic pollutants

Question 8

What can POPs do?

Answer 8

They can alter of block the hormone system of individual invertebrate and can chain immune system and possibly produce carcinogenic effects

Question 9

What are the chemicals of greatest concern worldwide?

Answer 9

Highly chlorinated organic molecules known as organochlorines (OCs)

Question 10

POP has what kind of solubility in water and accumulation in fat?

Answer 10

• Low solubility

- High accumulation

Question 11

What does PCH stand for?

Answer 11

Polychlorinated hydrocarbons

Question 12

What does PCB stand for?

Answer 12

Polychlorinated biphenyls

Question 13

What are PCHs examples of?

Answer 13

PCB

Question 14

What are PCB?

Answer 14

They are organic chlorine compounds that vary based on the ratio of chlorine to biphenyl and the production temp

Question 15

Acute toxicity

Answer 15

Quick death

Question 16

Sublethal/chronic toxicity

Answer 16

Impairment of growth, breeding success

Question 17

Carcinogenicity toxicity

Answer 17

Impairment, death

Question 18

Mutagenicity and teratogenicity toxicity

Answer 18

Effects on future generations

Question 19

Genotoxicity

Answer 19

Possible effects on future generations

- Effects genes/ DNA

Question 20

What happens to the [ ] of bioaccumulation over time?

Answer 20

It increases

Question 21

What is the 2nd attribute of many toxic substances?

Answer 21

Resistance to degradation

Question 22

How are toxins that have a vapour phase transported?

Answer 22

Through the atmosphere

Question 23

How do hydrophobic contaminants that contain high bioaccumulation get absorbed? (3 things)

Answer 23

Through the…

1. Gills
2. Guts
3. External surfaces of living organisms

Question 24

How do hydrophilic contaminants that contain high bioaccumulation get absorbed?

Answer 24

Usually reminded dissolved in the water

Question 25

How are PCBs released?

Answer 25

1. Leakage 2. Spills 3. Escape from waste storage sites

Question 26

What are 4 examples of toxic trace metals?

Answer 26

1. As 2. Cd 3. Hg 4. Pb

Question 27

What is an important contaminant for wetlands?

Answer 27

Mercury

Question 28

What is one of the worst chemicals humans every synthesized?

Answer 28

PCBs

Question 29

Why are lead levels increasing?

Answer 29

It is due to human activity | - Industrial revolution

Question 30

Lake Superior is now acting more like a ____ rather than a ____

Answer 30

- source | - sink

Question 31

Hydrophilic

Answer 31

Those that dissolve readily in water (water-loving) = high solubility

Question 32

Hydrophobic

Answer 32

Those that don't readily dissolve in water (water fearing) = low solubility

Question 33

Where does mercury accumulate?

Answer 33

In tissues | - not fat

Question 34

What causes dips in the graph?

Answer 34

High sediment loading followed by dilution

Question 35

The extent to which a contaminant is bioavailable upon its arrival in aquatic systems is mainly determined by what?

Answer 35

By its solubility in water

Question 36

Hydrophilic contaminants are more likely and less likely to do what compared to hydrophobic?

Answer 36

- Contaminants are more available for direct nutrient uptake - Less likely to be removed by sedimentation or filter-feeding organisms

Question 37

What does electronegativity represent?

Answer 37

The power of an atom to attract electrons to itself in a covalent bond

Question 38

The greater the electronegativity is the ____ the solubility is

Answer 38

Lower

Question 39

What does QSAR stand for?

Answer 39

Quantitative Structure Activity Relationships

Question 40

What is QSAR?

Answer 40

It is a model that first summarizes a supposed relationship between chemical structures and biological activities in a data-set of chemicals

Question 41

Octanol

Answer 41

Describes the equilibrium [ ] between water and a solvent

Question 42

What does Kow indicate? (4 things)

Answer 42

1. The uptake potential by organisms 2. The potential for bioaccumulation from the water 3. The biomagnification potential in food webs 4. The residence time of persistent organic pollutants in the enviro

Question 43

More electronegativity has a ___ octanol solubility

Answer 43

High

Question 44

Least soluble

Answer 44

Highest octanol

Question 45

High Kow

Answer 45

More neutrophilic the more they accumulate in fat | - Hydrophobic

Question 46

What does Kow serve as?

Answer 46

A surrogate for the solubility of toxic compounds in water

Question 47

Low Kow

Answer 47

Hydrophilic

Question 48

Biomagnification

Answer 48

The cumulative increase observed in the [ ] of persistent contaminants at successively high levels in food webs - Obtained from the predator:prey [ ] ratio

Question 49

Bioaccumulation Factor (BAF)

Answer 49

Represents the organism [ ] : enviro [ ] ratio

Question 50

What class is most effected by bioaccumulation and least affected?

Answer 50

``` Most = Class 3 (long food chain) Least = Class 1 (short food chain) ```

Question 51

What happens to PCB levels in the body as trophic levels increase?

Answer 51

They increase | - Cause harm/damage