Data sourced from:
- http://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/general_facts/
- http://www.ncbi.nlm.nih.gov/books/NBK53010/
- http://www.bbc.co.uk/worldservice/sci_tech/features/health/tobaccotrial/inacigarette599.htm
- https://openclipart.org/detail/121591/human-body-organs-by-ozhank
- http://www.ewg.org/enviroblog/2014/07/new-duke-study-finds-reducing-air-pollution-saves-lives
- http://www.ewg.org/enviroblog/2007/03/rising-cost-breathing
- http://www.arb.ca.gov/research/health/pm-mort/pm-mortdraft.pdf
- http://www.cdc.gov/niosh/docs/88-116/
