I think you should weight the benefits vs the harms. Smoking in front of your plants releases CO2 because you're fucking breathing, so why smoke when you could just breathe??? That to me would be a enefit-for both you and your plants. Secondly, smoking releases carcinogens, thereby polluting the air. Adding smoke to the plant's environment takes away from the the amount of beneficial things in the air, e.g. CO2, humidity level. Does that sound like a good idea? I don't think you would be asking the question if you just exercised some common sense. smoking is bad for you for the same reasons it's bad for your plants. (or vise-versa?) peace.