Flint Michigan Crisis
Problem Set 9
1) Go to the link provided to read the first two pages of the article on Flint Michigan Crisis (marked
as page 5 and 6 on the article; up to Toxic Levels of Lead) and answer the following questions.
https://www.acs.org/content/dam/acsorg/education/resources/highschool/chemmatters/issue
s/2016-2017/December%202016/chemmatters-dec2016-flint-water-crisis.pdf
a) What were the initial complaints regarding the quality of water by Flint residents after the
city of Flint switched over to the new water source?
b) List any two contaminants that were present in the new water supply?
c) What are some health concerns and/or known effects of these contaminants?
d) What is the maximum level of lead contamination limit set by the EPA in tap water?
2) To save money, you consider moving in with your cousin, who is a smoker. You move in at age
20 and take 2 weeks each year for vacation. Benzene is a chemical found in tobacco smoke.
Is benzene a carcinogen or noncarcinogen?
Calculate the lifetime risk for benzene using the following parameters:
Concentration of benzene in homes of smokers = 10.5 µg/m3
Inhalation rate = 20 m3/day
Absorption efficiency = 50%
Average weight of adult male = 70 kg
Slope factor = 1.5 kg-day/mg
Lifetime = 70 yr
3) What is the dry weight percent composition for the following combined waste?
Component %Composition %Moisture (wet weight)
Paper 40 6
Yard/Food 30 60
Other 30 3
