CE 397:Environmental Risk Assessment
Homework Assignment #4: Atmospheric Transport Modeling and Indoor Air Quality
Benzene concentration is stack gas = 2 parts per thousand by volume
Stack gas temperature = 130 C
Physical stack height = 25 m
Stack diameter = 1 m
Stack gas exit velocity = 8 m/s
Wind speed at 10 m above surface = 3 m/s
Wind speed at physical stack height = 4 m/s
Temperature at ground-level = 8 C
Environmental lapse rate = -1 C/km
Assume that Leo spends 20 minutes showering every day (while in the shower he continues to lecture to a group of hypothetical, enthusiastic, but shocked students). You may assume the following conditions for your analysis:
Volume of Leo's shower stall = 1.8 m3.
Leo likes a high flow rate of water: 9.1 L/min.
Leo likes a coarse water spray: KLA = 1.7 L/min
Leo likes his showers fairly warm: water temperature = 35 C
Air flow rate entering and exiting Leo's shower stall = 379 L/min
Initial benzene concentration in Leo's shower (start of showering event) = 0 mg/L
Concentration of benzene entering Leo's shower from atmosphere outside of shower = 0 mg/L
Leo breathes at a rate of 20 m3/day
Leo drinks 2 L of water per day
Compare the amount of benzene that Leo inhales on a daily basis (while showering only) to that which he ingests on a daily basis.