This is an extremely open ended question, and maybe you would like to use the "Edit post" function to ask a more specific and focused question.
However, a short answer to you general question is that toxins, be it smoke, other chemicals or radiation are thought to have their effects of mutating the DNA by eliciting the production of Free Radicals which actually cause the mutations. many anti cancer therapies focus on Free radical scavenging. for example...
This is an extremely open ended question, and maybe you would like to use the "Edit post" function to ask a more specific and focused question.
However, a short answer to you general question is that toxins, be it smoke, other chemicals or radiation are thought to have their effects of mutating the DNA by eliciting the production of Free Radicals which actually cause the mutations. many anti cancer therapies focus on Free radical scavenging. for example...
http://www.ncbi.nlm.nih.gov/pubmed/12168851
http://www.ncbi.nlm.nih.gov/pubmed/11299741
http://ift.confex.com/ift/2005/techprogram/paper_29506.htm
http://www.cjmed.net/journal/articleInfo/id/244?PHPSESSID=e04ab702be091720e4d0209436fb8c3b