PHWM 2110 EXAM TWO UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

PHWM 2110 EXAM TWO UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS

Question:
1. What is environmental transport?
Answer:
How environmental agents travel and where they go
Largely determined by the physics of motion

Question:
2. What is environmental fate?
Answer:
What the environmental agents become
Largely determined by chemical and biological transformation processes and relative partitioning in media

Question:
3. Scales of Transport
Answer:
Molecular: <<2mm (ex: molecular diffusion)
Microscale: 2mm-2km (ex: eddies, small plumes, exhaust)
Mesoscale: 2-2000km (thunderstorms, tornados)
Synoptic scale: 500-10000km (ex: weather fronts, tropical storms, hurricanes)
Planetary scale: >10000km (ex: global wind systems, global warming)

Question:
4. Structure of the atmosphere
Answer:
Troposphere, stratosphere, mesosphere, thermosphere
Based on the vertical variation of air temperature

Question:
5. Determinants of transport in water
Answer:
Dilution: diffusion, advection, turbulence
Mixing: temperature gradients, friction
Sorption: adsorption, absorption
Sedimentation

Question:
6. Transport in soil
Answer:
Soil includes solid, liquid, and gaseous phases
Structured in layers; composition varies greatly Characteristics determine the rate and spread of chemical
contaminants

,Question:
7. Determinants of transport in soil
Answer:
Nature of the chemical
Water solubility
Soil type
Soil moisture, pH, temperature

Question:
8. Important attributes of chemical contaminants
Answer:
Chemical structure: inorganic or organic
Physical state: melting, boiling points, density
Solubility: aqueous, non-aqueous

Question:
9. Bioaccumulation
Answer:
Occurs within an organism, where a concentration of a substance builds up in the tissues and is absorbed
faster than it is removed

Question:
10. Biomagnification
Answer:
Refers to an increase in the concentration of a substance as you move up the food chain

Question:
11. Bioconcentration
Answer:
The intake and retention of a substance in an organism entirely by respiration from water in aquatic
ecosystems or from air in terrestrial ones

Question:
12. Factors favoring bioaccumulation
Answer:
Passive uptake and elimination by organism
Substances that are metabolized slowly
Low water solubility, high lipid solubility
Higher lipid content of host tissue

Question:
13. How is particulate matter characterized and measured?
Answer:
Characterized by aerodynamic diameter: PM2.5, PM10, fine PM
Measured by: mass per volume and microns

, Question:
14. What are some examples of unitless concentrations?
Answer:
Percentages
ppm, ppb, ppt

Question:
15. Ideal gas law
Answer:
PV=nRT
P = pressure V = volume N = number of mols of gas R = universal gas constant T = absolute temperature

Question:
16. Relationships within the ideal gas law
Answer:
Both pressure and volume are directly proportional to temperature
Allows us to understand how gases respond to changing conditions

Question:
17. Risk
Answer:
Risk = hazard x exposure
Both hazard and exposure MUST be present

Question:
18. Hazard
Answer:
An inherent hazard must be present which is capable of injuring someone (ex: a toxic chemical or agent)
Hazard is associated with the agent, but does not imply risk

Question:
19. Main measures of exposure in epidemiological studies
Answer:
Nominal: presence or absence of agent
Ordinal: low, medium, or high categories of exposure Interval: categories representing known intervals
(ex: quarters)
Ratio: intervals with a zero, can take any numerical value

Question:
20. Sources of variability in exposure values
Answer:
Variation over time and space
Variation in pollution sources
Goal: a representative statistical sample

Question:
21. Exposure in statistical terms