Air pollution on the state and local level due to automobile and factory emissions

In ESSAY format describe the cycle of carbon monoxide concentration (AQI). Address the following issues:
How does the time of day affect the buildup of CO? Why do CO levels vary at different times?

Sunrise (5:30 AM)
Morning Rush (8:30 AM)
Mid day (1:25 PM)
Afternoon rush (5:15 PM) Night

How does the size of the city (its growth) affect the buildup of CO? Small Town (1 bar), Medium City (2 bars), Large City (3 bars), Major Metro (4 bars) http://coep.pharmacy.arizona.edu/air/cocity/cocity…
What is carbon monoxide? Why is it a good indicator of air quality? What happens to CO once it is released into the atmosphere?