More sources that I have used to help me further develop my idea:
http://www.who.int/phe/health_topics/outdoorair/databases/en/
http://www.who.int/phe/health_topics/outdoorair/databases/AAP_database_results_2014.pdf?ua=1
http://www.wisegeek.org/what-is-the-difference-between-air-and-oxygen.htm
http://www.airnow.gov/index.cfm?action=aqibasics.particle
http://waqi.info