Ecotoxicology Flashcards
How do human activities affect ecosystems?
Human activities disturb ecosystems.
What type of human activities disturb ecosystems?
- Industrial and agricultural activities
- Creation of waste which releases different substances or contaminants into the air
What is a contaminant?
Something which causes harm and is not supposed to be present
What type of substances cause harm to ecosystems?
- Inorganic contaminants
- organic contaminants
- Microbial contaminants
- Radioactive contaminants (nuclear)
What is toxicity threshold?
The amount of a contaminant that will cause harm in an organism. Harm from contaminant can range from mutations to fertility loss to death.
The toxicity of each contaminant depends on what factors?
- Concentration
- Type of organism
- Duration of exposure
Dosage is dependent on what?
Mass
What things are poison?
All things, it just depends on the dosage
How do we calculate who took the highest dosage?
Dose=m/v
Dose= dose(amount taken)/weight
What is toxicity threshold?
The minimum level of concentration at which the contaminant causes harm (mg/kg)
ANY HARM - EX. HEADACHE
Describe lethal dose
The amount of contaminant necessary to kill an organism in a single dose
Describe lethal dose fifty (LD50)
The dose that causes death within 50% of individuals
What is bioaccumulation?
The degree to which a toxin can accumulate in a living organism through inhlation, ingestion or dermal exposure
These contaminants resist natural degradation and cannot be eliminated
Bioaccumulation - once the contaminated organism is consumed, what happens?
The toxin can become stored in the fat tissues of the consumer
The consumers must consume a lot of producers causing the concentration of the toxin to be amplified in the consumer than in the producer and so on.
What is bioaccumulation?
The increase in concentration of a toxin as it passes through to higher trophic levels of a food web (since it degrades extremely slowly and it is not metabolized)
