lecture 2

Question 1

Ecotoxicology

Answer 1

Science of contaminant effects on ecological entities

Question 2

What is a Toxicant

Answer 2

A toxicant is an agent that can produce an
adverse response in a biological system.
– Non-point sources: runoff, groundwater,
atmospheric
– Point sources: outfalls and stacks

Question 3

Stressor

Answer 3

Response to an effect of a recent, disorganizing or
detrimental factor at any level of ecological organization

Question 4

Xenobiotic

Answer 4

A foreign chemical or material not produced in nature and
not normally considered a constitutive component of a
specified biological system

Question 5

Pollutant

Answer 5

A substance that occurs in the environment at least in part
as a result of anthropogenic activities, and which has
deleterious effect on living organisms
-Copper

Question 6

Contaminant

Answer 6

A substance released by anthropogenic activity
-Creosote
-Copper

Question 7

What is in Water?

Answer 7

Dissolved O2
Carbon
Cations, Mg, Na, K, Ca
Anions, Cl, SO
Alkalinity CO3 (Carbonate)
pH, OH, H
Organic matter
Nutrients: NH3, PO4, NOx

Question 8

Determinants of Fate

Answer 8

Solubility
* Hydrolysis/Photolysis
* Sorption (ad or ab)
* Volatility
* Temperature
* Salinity
* Rate of release
* Bioaccumulation
* Biotransformation
* Persistence
* Mobility of chemical
* Chemical form
– Speciation

Question 9

Factors Related to Exposure

Answer 9

Compound must:
– Come in contact and react with an appropriate
receptor site of the organism
– Have a high enough concentration to elicit an
effect
– Have sufficient contact time to elicit an effect