Environmental Toxicology Flashcards
ESA Exam (22 cards)
Name 3 Effects of Physical Properties of Water Bodies
- Eutrophication
-comes from sewage and nutrient overflows - Sediment pollution
-Excess runoff
-Sources: erosion from ag, logging, overgrazing, degraded stream banks, overgrazing, construction, mining - Thermal pollution
-Industries and nuclear power plants
-warmer water has less capacity to hold oxygen (leads to biological stress)
4 Layers of the Atmosphere
Troposphere, Stratosphere, Mesosphere, Thermosphere
4 Main Molecules in the Atmosphere
Nitrogen, Oxygen, CO2, Argon (and Water Vapor)
Atmospheric Pollutants
Nitrogen oxides (NOX) –> leads to acidification of waters and soils
Particulate matter: PM 2.5 and 10
Ozone (O3)
Metabolism
Chemical reactions carried out in organism– a response to intake of pollution
Hydrophilic
Likes water (soluble in water)
Hydrophobic
Does not like water (insoluble in water)
Lipophobic
Doesn’t like fats
Lipophilic
Likes fats (dissolves in fats, oils, etc.)
Why is PFAS so pervasive in the environment?
It is hydrophobic (and hydrophilic?) and lipophilic (hard to break down in nature)
Why are Novel Entities a cause for concern?
Their presence in nature has been relatively short, and we don’t know what their long-term evolutionary effects could be.
Cocktail effect
Potentials for reactions between different chemicals. Also can make it hard to link a physiological, biochemical, or other change to a single pollutant
What are Potentiation/synergistsic and antagonistic effects between pollutants?
Potentiation/Synergistic: Increasing each other
Antagonistic: Balancing each other
What are pollutants transported by?
Water, air, soil, and organisms
What does PBT stand for?
Persistant, Bioaccumulative, and Toxic
What are some characteristics of a persistent pollutant?
-Won’t be broken down in nature (e.g. hydrophobic and lipophilic)
-Is favored by low temperatures (harder to break down)
-Allows substance to remain in nature for a long time
-Allows for non-local distribution of pollutant (via air, water, etc.)
-Long half-life (conditions also matter for half-life of pollutants)
Bioaccumulation
The process through which pollutants are stored and accumulate in the fats of an animal, and enter the bloodstream. Hydrophilic molecules are more readily excreted through metabolization. Lipophilic molecules are more likely to stay in fatty tissues of organisms.
Biomagnification
Concentrations of pollutants increase in higher trophic levels
Endpoints for toxicity testing and assessment
Death
Biochemical (good or bad responses in organisms)
Physiological (organ damage, etc.)
Reproductive (e.g. thinning of egg shells)
Behavioral (e.g. changes to mating patters)
What are POPs, and what are some examples of them?
Persistent Organic Pollutants
They contain carbon, are long-lived, and may be toxic
E.g. Pesticides (like DDT), Industrial chemicals, by-products
Define PBT-M
Persistence - resistance to degradation in the environment
Bioaccumulative- Organisms storing substances + excretion/metabolization
Toxic- Detrimental effects on organisms- differs between individuals and species
Mobile- Transportation potential. Often charged, and water soluble, so can travel in aquatic environments.
Is it the lipophilic or hydrophilic substance that is more
bioaccumulated? Explain your answer.
Lipophilic substances are commonly stored in fatty
tissues of organisms so they are more readily
bioaccumulated. However, hydrophilic substances
are water soluble meaning that those substances
are easily excreted.
