Lecture 5: Pollutants and Risk Assessment

Question 1

Environmental Stressor=

Answer 1

factors that constrain productivity, reproductive success, and ecological development

Question 2

disturbance=

Answer 2

episodic, but intense influence that causes severe biological and ecological damage

Question 3

pollution=

Answer 3

exposure to chemicals or energy (or potentially other stressors) at an intensity that exceeds the tolerance of organisms

Question 4

contamination=

Answer 4

when potentially damaging stressors are present in the enviro, but at intensities too low to cause damage

Question 5

T/F
contamination and pollution are the same thing

Answer 5

false
- pollution= toxicity/ damage can be measured
- contamination= stressors are present, but at intensities too low to cause damage

Question 6

pollution can be either natural or ____

Answer 6

anthropogenic

Question 7

What are the 6 different types of pollution?

Answer 7

1. chemical
2. thermal
3. biological
4. noise
5. light
6. aesthetic

Question 8

just because something is toxic doesn’t mean the concentration is high enough to:

Answer 8

be a pollutant/ cause toxicity

Question 9

chemicals =

Answer 9

any material with a definite chemical substance
- chemicals are not always bad!

Question 10

list 3 examples of chemical pollution

Answer 10

1. lead: anti-knocking compound (toxic)
   - used to be added to fuel to make it burn faster/ more effectively
2. petroleum (oil spills)
3. pesticides

Question 11

secondary pollution=

Answer 11

the release of substances that react in the enviro to synthesize chemicals of greater toxicity
eg= ozone produced by CO + O2
not harmful until they react w enviro

Question 12

thermal pollution=

Answer 12

when the release of heat into the enviro results in ecological stress (some species cannot tolerate temperature extremes)

Question 13

what are 4 examples of thermal pollution?

Answer 13

1. deep sea thermal vents
2. power plants: heat up the water around them, which changes the natural community to organisms who can tolerate the heat
3. hot springs
4. heat islands in cities

Question 14

describe an urban heat island

Answer 14

cities are usually warmer than the surrounding rural/ natural area
- increases costs to cool in summer, but decreases costs to heat in winter

• more frequent heat waves will make this worse :(

Question 15

biological pollution=

Answer 15

when humans release organisms beyond their natural range
- invasive species
- pathogens

Question 16

noise pollution=

Answer 16

when the level of ambient sound becomes distracting to the normal activities of humans or are detrimental to wildlife

Question 17

examples of noise pollution (2)

Answer 17

• cars
• cargo ship noise impacts beluga whales
• diff rxns from diff animals depending on type of noise

Question 18

sensory pollution is __ and __ pollution

Answer 18

noise and light

Question 19

light pollution=

Answer 19

when artificial light levels are detrimental to wildlife
- often occurs when excess light is bright enough to obscure stars in the night sky

Question 20

give 2 examples of light pollution

Answer 20

• search lights disorient birds who migrate based on the moon
• moths are attracted to light

Question 21

aesthetic pollution=

Answer 21

visual images or enviros that are displeasing to many people
- eg McDs sign

*diff b/c it only impacts humans, BUT we are part of the enviro

Question 22

_____ pollution is the most complex pollution and has the largest impact

Answer 22

chemical

Question 23

environmental toxicology=

Answer 23

the study of the environmental factors that can influence the exposure to organisms to potentially toxic chemicals

Question 24

ecotoxicology=

Answer 24

the study of the directly poisonous effects of chemicals, in addition to their indirect ecological effects

Question 25

What is the subtle difference b/w enviro toxicology and ecotoxicology

Answer 25

enviro toxicology= how chemicals react with the enviro ecotoxicology= impacts of the chemicals on the enviro

Question 26

acute toxicity=

Answer 26

short-term exposure to a chemical in a high enough [ ] to cause biochemical or anatomical damages (even death)

Question 27

chronic toxicity=

Answer 27

long-term exposure to low or moderate [ ] of a chemical. over time, chronic exposure may cause biochemical or anatomical damage, or become lethal

Question 28

How is toxicity measured? LD50=

Answer 28

LD50= the amount of a compound required to kill half of a population of experimental animals

Question 29

T/F all chemicals & compounds are toxic at a certain level (even water!)

Answer 29

true

Question 30

explain the 3 dose response curves. What are they used for?

Answer 30

used for contaminants and medicines - ED50= effective dose 50% (produced desired, therapeutic effect on 50% of the pop) - TD50= toxic dose 50% (produces a defined toxic effect in 50% of the pop) - LD50= lethal dose 50%, kills half of the pop

Question 31

synergistic effects=

Answer 31

interactive impacts of toxins that are more than, or diff from, the simple sum of their constituent effects - they amplify each other when they're together and cause unexpected rxns - eg baking soda and vinegar

Question 32

List 6 types of toxins and what they do

Answer 32

1. carcinogens: cause cancer 2. mutagens: cause DNA mutations 3. teratogens: cause harm to unborn babies 4. allergens: overactivate our immune response 5. neurotoxins: impact our nervous system (eg mercury) 6. endocrine disruptors: act at the hormonal level and impact endocrine system

Question 33

List 4 examples of surface water pollution

Answer 33

1. road runoff (contains oil and HCs) 2. farm runoff (fertilizer and animal waste= cause algal blooms) 3. human waste/ sewage 4. thermal pollution from power plants etc: makes surface water too warm

Question 34

How does the global distillation effect impact chemical pollution?

Answer 34

chemicals travel from warmer to cooler regions - doesn't necessarily impact the source of the pollutant - this is why there's so much pollution in the arctic

Question 35

persistent organic pollutants (POPs)=

Answer 35

organic compounds that are resistant to degradation/ decomposition via biological, chemicals, and photolytic (light) processes - semi-volatile, evaporate slowly, low water solubility, high lipid solubility - accumulate in tissues of living things - involved in the global distillation effect

Question 36

what are the 3 main categories of POPs listed under the Stockholm Convention (2001)

Answer 36

- pesticides - industrial chemicals - by-products (unintentional production)

Question 37

Bioaccumulation=

Answer 37

build-up of toxins in tissues of animals at the individual level

Question 38

Biomagnification=

Answer 38

the pollutant in individuals magnifies up the food chain (between individuals)

Question 39

biomagnification impacts ___ the most

Answer 39

predators (top of the food chain= get highest [ ] of toxin)

Question 40

quantitative environmental risk assessment= It's based on which 3 main factors?

Answer 40

(can measure) evaluation of the risks associated with some sort of hazard in the enviro Based on 3 main factors: 1. likelihood of encountering the hazard 2. likely intensity of the hazard 3. the biological damage that is likely to result from predicted exposure

Question 41

Environmental Impact Assessment=

Answer 41

a study of the potential impacts of a project/ activity on the enviro (eg building a power plant)

Question 42

5 steps of Environmental Impact Assessment=

Answer 42

1. screening and scoping 2. assessment of enviro risk 3. mitigation 4. decision making 5. monitoring (must be able to intervene!)