andy

Smoking in general:
I saw a psak of the Rabbanut Harashit in Israel concerning the topic of a Mamzer. A child was sick in hospital
and needed a blood transfusion. The father volonteered as a donor and after checking the results the doctors said that this could not be the father of this child. Now the question arises if this child is considered a Mamzer with all the consequences. The Rabbanut decided that medicine is a field which is developing all the time. What was considered the absolute truth 50 years ago was proved wrong and a new theory took its place and is now considered as a new absolute truth. If doctors say that the father cannot be parent of this child this represents todays sight of things. In the future a new theorie could be developed which could change the whole picture. We can therefore rely on the opinion of doctors ” lekula ” but not ”lechumra”. For this reason the child is not considered a Mamzer.
If doctors say smoking is detrimental to your health we cannot forbid smoking lehalacha because the proof of the danger of smoking cannot finally be decided.
All the above is only an idea which may be wrong, but I saw Tzadikim who were smoking and maybe this is an explanation for their doing so.