Smoking can be very enjoyable and relatively harmless if, after you inhale, you blow the smoke back out again within, oh, about 25 seconds. Just remember, be sure and blow the smoke out again.
Had a pulmonologist tell me that if you smoke, keep it under 15 per day and smoke no further down the filtered cigarette than a thumbs width from the filter. If possible stop at two finger widths from the filter (smoke only filtered cigarettes) ... the second half of the cigarette accumulates the tar and such drawn from burning the first half of the cigarette, so smoking the second half has much more tar and chemicals than the first half. [We were having a smoke on the outside patio at a cocktail party, or rather he was bumming a smoke from me on the patio.]