Children long-termly exposed to second-hand smoke have the same likelihood of developing smoke-related disease as any smoker. For this reason, as well as the already present adversity of toxins in our environment, it should be a societal priority to protect children from deliberate and direct toxin poisoning via cigarette smoke. The act, itself, should be legally pursued as a form of child abuse.
Long-termly, this precaution will save in health care costs and lost in human capital down the road.