A little light reading :-

http://www.surgeongeneral.gov/library/secondhandsmoke
http://monographs.iarc.fr/ENG/Monographs/vol83/volume83.pdf
http://news.bbc.co.uk/1/hi/health/medical_notes/3235820.stm
http://news.bbc.co.uk/1/hi/health/2925633.stm
http://www.healthinsite.gov.au/topics/Passive_Smoking
http://quitsmoking.about.com/cs/secondhandsmoke/a/secondhandsmoke.htm
http://www.bmj.com/cgi/rapidpdf/bmj.38370.496632.8Fv3.pdf