My father smoked, starting in his teens & all through adulthood. Soldiers on active service during WW2, were routinely given free cigarettes. I can remember my father showing me a tin of army issue 'fags'. As a newborn, I slept in a cot in my parent's bedroom. My father always smoked a cigarette before turning out the light. According to my mother, she saw him on many occasions, rocking me in his arms with a cigarette poking out of the corner of his mouth. Her main concern was that the ever-extending ash might fall on me.
         Thank you, Jack, for posting the link. The epigenetic effect could hold many answers to some of my life-long health problems.
                                                Nigel.