Impossible to calculate, and could probably be solved by tort anyways.
Definitely not solvable by tort as the legal costs would be disproportionate unless one resorts to class action, and even then just simply dealing it with taxes would be cheaper. The "redress all harm by torts theory" breaks down when an action causes a small amount of harm to a large number of people because the cost of the tort becomes impractical. In the case of second-hand smoke, it might be possible to deal with the damage done to employees via tort, but not that done to customers and the damage done to the customers will be far greater.