Chapter 23 (exam 2)

Question 1

Risk assessment

Answer 1

Science meets policy

control uncertainty to lower population risk

No regulations - population becomes the test subject

Economics - how does regulation effect an economy.

–ex Methyl bromide as soil fumigant for strawberries

Polititcs - Dietary supplements exept from FDA regulation because the American Herbal Products Association

Question 2

Tox Societies

Answer 2

Society of Tox - improve use of science to make a safer world

Society of Environmental Tox and Chemistry - use science in environmental policy and decision making

Question 3

Hazard

Answer 3

extent to which a chemical under any exposure scenario can cause biological damage

• reactivity, radioactivity, corrosiveness
• quantified by LD50, LC50, ED50
• hazard cannot be changed, but exposure can be changed

Question 4

Hazard Assessment

Answer 4

• measure bio effect
• determine dose response relationships due to variations (age, gender, genetics, occupation, species)

Question 5

Exposure Assessment

Answer 5

-characterizing the magnitude, duration, frequency of exposue of a population

Exposure - interaction of target organism with toxicant through environmental media and by any route of absorption

Question 6

Risk Characterization

Answer 6

-put hazard and exposure together

risk = hazard x exposure

• how damaging is the chemical and how likely is it that a population will encounter the chemical
• risk is proportional to the area of overlap

Question 7

Probabalistic risk assessment

Answer 7

• no overlap - can have an effect, but effective conc is likely not in nature
• heavy overlap - needs to be fixed, population is effected
• inform policy, reevaluate risk then reevaluate

Question 8

Risk Management

Answer 8

make decisions based on data

• new policies, regualations, restrictions ex. prescription labels
• change exposure distribution
• must change chemical in order to change the hazard

Question 9

Cu and Zn in Stormwater

Answer 9

Brake pad wear: Cu

Tire wear: Zn

CMC: critirium max conc (acute tox limit)

CCC: critirium continuous conc (chronic tox limit)

Risk management outcomes: Cu banned in brake pads trying to decrease Cu in urban stormwater, coming from nonpoint source

-tire manufacturers are lowering zinc composition