Pollution

co2 to oxygen conversion
http://www.elephantjournal.com/2009/03/clean-fresh-air-with-these-three-common-houseplants-kamal-meattle/ The Areca Palm (or Chrysalidocarpus lutescens) is does great air cleansing work during the day. About 4 shoulder height plants per person should do the trick. The Mother-in-law’s Tongue (or Sansevieria trifasciata) takes over by converting CO2 to O2 at night. You want about 6 to 8 of these waist high plants per person. The Money Plant (or Epipremnum aureum) does the job of filtering out removing Formaldehyde and other VOC’s (Volatile Organic Compounds).

http://www.ted.com/talks/kamal_meattle_on_how_to_grow_your_own_fresh_air.html

http://en.wikipedia.org/wiki/NASA_Clean_Air_Study from http://en.wikipedia.org/wiki/Sansevieria_trifasciata, https://archive.org/details/nasa_techdoc_19930072988

http://lifehacker.com/#!5149643/three-plants-that-give-you-better-indoor-air

http://www.diligentgardener.co.uk/2014/01/plants-for-sustainable-living.html

place cornmeal around an antheap. Ants eats the cornmeal but can't digest it, killing the colony

air quality
http://www.ceroi.net/reports/pretoria/issues/air_qual/overview.htm

http://www.saaqis.org.za/

http://www.foodexposed.co.za/long-term-pollution-exposes-people-to-structural-changes-in-the-brain/#more-5602 air pollution causes dementia