Okay Katex,
There are approx 50,893,318 adults in the Uk, so a 5th are smokers......I would say that is a minority.
Second hand smoke, well according to the WHO, The Surgeon General, International agency for the research on cancer, it does exist.
Here is some reading if you are interested,
http://www.who.int/tobacco/framework...TC_english.pdf
http://monographs.iarc.fr/ENG/Monogr.../mono83-7E.pdf
the evaluation is here 'There is sufficient evidence that involuntary smoking (exposure to secondhand or ‘environmental’ tobacco smoke) causes lung cancer in humans.'
Watch the film Thankyou for smoking, might make you sit up a bit.
re aviation, well if you want to start a thread on that we could argue, however if you have even been in a car or bus, then you are causing lots of damage to the environment as well.