Second Hand Smoke

Me and my friend are having this huge argument about second hand smoke.

I say it's insignificant and should be allowed, he says it's very significant and should be banned.

What are your thoughts?

His sources:
http://www.philipmorrisusa.com/en/he...hand_smoke.asp
His dad, the doctor; 30 yrs experience; hasn't done a study

My sources:
http://www.davehitt.com/facts/epa.html
http://www.davehitt.com/facts/who.html
http://www.fumento.com/disease/passive-smoking.html
http://skepdic.com/news/newsletter41.html
http://www.junkscience.com/news2/zion.htm
http://www.junkscience.com/news2/wtedets.htm

He still refuses to listen to me, what do you guys think?