When cigarette smoke is blown into the environment, its chemical constituents don't just vanish into thin air.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/battle-against-lingering-harmful-residue-smoking-leaves-behind
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/medical-express
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/smoking
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tobacco
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/toxins