Lec 7 Flashcards
(34 cards)
Environmental toxicology
The study of environmental factors that can influence the exposure of organisms to potentially toxic chemicals
How chemicals react with the environment
Ecotoxicology
The study of the poisonous effects of chemicals as well as their indirect ecological effects
Impacts of chemicals on the environment and its inhabitants
Acute toxicity
Short term exposure to a chemical in a high enough concentration to cause damage or death
Chronic toxicity
Long-term exposure to low or moderate concentrations of a chemical. Over time, chronic exposure may cause damage of become lethal
LD50
The amount of a compound required to kill half a population of experimental animals
Measured in amount of chemical per unit body weight
ED 50
Effective dose 50 percent
Therapeutic effect (a specific effect)
TD50
Toxic dose 50 percent
(A toxic effect)
Synergistic effects
Interactive impacts of toxins that are more than the simple sum of their constituent effects
(eg. 2+2=8)
Types of toxins
Carcinogens (eg smoking)
Mutagens (eg X ray)
Teratogens (Affects child development during pregnancy eg. alcohol)
Allergens (eg. dust/pollen)
Neurotoxins (affect neurology eg. mercury)
Endocrine Disruptors (eg. compounds in plastic)
Decreasing water pollution
Reduce agricultural runoff
Improve wastewater management systems
Stricter cooling regulations for power plants
Global distillation effect
Chemical pollution generally is carried from warmer to colder environments (towards poles or mountain tops)
Pollution in the west generally affects the east
Persistent organic pollutants (POPs)
Organic compounds that are resistant to degradation/decomposition via biological chemicals, and light processes
POPs categories
Pesticides
Industrial chemicals
By-products
Bioaccumulation
Pollutants being built up in the tissue of an animals
Biomagnification
Increase in toxic build up from consuming animals with pollutant build up in the tissue
Bioaccumulation starts
At lower levels of the food chain
Quantitative risk assessment
Evaluation of the risks associated with a hazard
1 The likelihood of encountering the hazard
2 The likely intensity of the hazard
3 The biological damage that is likely to result from the predicted exposure
Environmental impact assessment
A study of the potential impacts of a project/activity on the environment
The precautionary principle
The precautionary approach shall be widely applied to protect the environment
Where there are threats of irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degredation
Long term tracking
Paleoecology
Inform conservation and restoration
Guide to future decision making about the environment
Uniformitarianism
The present is the key to the past
Analogy
Application of modern organismic features to ancient organisms
Paleolimnological approach steps
Select study lake
Select coring site or retrieve sediment core
Section and date sediment core
Sub sample sediments and isolate indicator of interest
Collect indicator data
Analyze data
The mesocosm approach
Chambers known as corrals (or mesocosms) isolate the environment and allow us to measure aspects in those chambers
