Lecture 5: Pollutants and Risk Assessment Flashcards
Environmental Stressor=
factors that constrain productivity, reproductive success, and ecological development
disturbance=
episodic, but intense influence that causes severe biological and ecological damage
pollution=
exposure to chemicals or energy (or potentially other stressors) at an intensity that exceeds the tolerance of organisms
contamination=
when potentially damaging stressors are present in the enviro, but at intensities too low to cause damage
T/F
contamination and pollution are the same thing
false
- pollution= toxicity/ damage can be measured
- contamination= stressors are present, but at intensities too low to cause damage
pollution can be either natural or ____
anthropogenic
What are the 6 different types of pollution?
- chemical
- thermal
- biological
- noise
- light
- aesthetic
just because something is toxic doesn’t mean the concentration is high enough to:
be a pollutant/ cause toxicity
chemicals =
any material with a definite chemical substance
- chemicals are not always bad!
list 3 examples of chemical pollution
- lead: anti-knocking compound (toxic)
- used to be added to fuel to make it burn faster/ more effectively - petroleum (oil spills)
- pesticides
secondary pollution=
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
thermal pollution=
when the release of heat into the enviro results in ecological stress (some species cannot tolerate temperature extremes)
what are 4 examples of thermal pollution?
- deep sea thermal vents
- power plants: heat up the water around them, which changes the natural community to organisms who can tolerate the heat
- hot springs
- heat islands in cities
describe an urban heat island
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 :(
biological pollution=
when humans release organisms beyond their natural range
- invasive species
- pathogens
noise pollution=
when the level of ambient sound becomes distracting to the normal activities of humans or are detrimental to wildlife
examples of noise pollution (2)
- cars
- cargo ship noise impacts beluga whales
- diff rxns from diff animals depending on type of noise
sensory pollution is __ and __ pollution
noise and light
light pollution=
when artificial light levels are detrimental to wildlife
- often occurs when excess light is bright enough to obscure stars in the night sky
give 2 examples of light pollution
- search lights disorient birds who migrate based on the moon
- moths are attracted to light
aesthetic pollution=
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
_____ pollution is the most complex pollution and has the largest impact
chemical
environmental toxicology=
the study of the environmental factors that can influence the exposure to organisms to potentially toxic chemicals
ecotoxicology=
the study of the directly poisonous effects of chemicals, in addition to their indirect ecological effects
What is the subtle difference b/w enviro toxicology and ecotoxicology
enviro toxicology= how chemicals react with the enviro
ecotoxicology= impacts of the chemicals on the enviro
acute toxicity=
short-term exposure to a chemical in a high enough [ ] to cause biochemical or anatomical damages (even death)
chronic toxicity=
long-term exposure to low or moderate [ ] of a chemical.
over time, chronic exposure may cause biochemical or anatomical damage, or become lethal
How is toxicity measured?
LD50=
LD50= the amount of a compound required to kill half of a population of experimental animals
T/F
all chemicals & compounds are toxic at a certain level (even water!)
true
explain the 3 dose response curves. What are they used for?
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
synergistic effects=
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
List 6 types of toxins and what they do
- carcinogens: cause cancer
- mutagens: cause DNA mutations
- teratogens: cause harm to unborn babies
- allergens: overactivate our immune response
- neurotoxins: impact our nervous system (eg mercury)
- endocrine disruptors: act at the hormonal level and impact endocrine system
List 4 examples of surface water pollution
- road runoff (contains oil and HCs)
- farm runoff (fertilizer and animal waste= cause algal blooms)
- human waste/ sewage
- thermal pollution from power plants etc: makes surface water too warm
How does the global distillation effect impact chemical pollution?
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
persistent organic pollutants (POPs)=
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
what are the 3 main categories of POPs listed under the Stockholm Convention (2001)
- pesticides
- industrial chemicals
- by-products (unintentional production)
Bioaccumulation=
build-up of toxins in tissues of animals at the individual level
Biomagnification=
the pollutant in individuals magnifies up the food chain (between individuals)
biomagnification impacts ___ the most
predators (top of the food chain= get highest [ ] of toxin)
quantitative environmental risk assessment=
It’s based on which 3 main factors?
(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
Environmental Impact Assessment=
a study of the potential impacts of a project/ activity on the enviro (eg building a power plant)
5 steps of Environmental Impact Assessment=
- screening and scoping
- assessment of enviro risk
- mitigation
- decision making
- monitoring (must be able to intervene!)
