Cigarettes are not only harmful to humans, but to our environment as well. Often times, cigarette butts are improperly disposed of and washed into our oceans when it rains. Cigarettes are highly toxic to marine life, even in the smallest of doses. Ingesting or even being in cigarette contaminated water can kill marine animals, making this a serious problem that needs to be addressed.
http://intraweb.stockton.edu/eyos/ehs/content/docs/smoking/Envl%20Butt%20Facts%20%203.pdf
http://www.unep.org/regionalseas/marinelitter/publications/docs/trash_that_kills.pdf
http://www.cdc.gov/tobacco/data_statistics/fact_sheets/health_effects/effects_cig_smoking/
http://www.mdpi.com/1660-4601/6/5/1691
http://intraweb.stockton.edu/eyos/ehs/content/docs/smoking/Envl%20Butt%20Facts%20%203.pdf
http://preventcigarettelitter.org/why_it_matters/why_it_matters.html