They are civil rather than criminal wrongs. Negligence occurs when unreasonable risk is created. The non-smoking father, a bus driver, is informed of the asthma attack while at work. As a direct consequence he becomes distracted and crashes the school bus he was driving, killing a school child and sending the father to hospital. In this scenario the child, the father and the province are likely the foreseeable victims, but the school child is not.
Recovery depends on foreseeability with respect to the victim and the injury.
So while the father is foreseeable with respect to some potential damage, he likely is not foreseeable with respect to the auto accident. Just because governments are reluctant to regulate ETS in the home environment does not mean there is a license to commit a tort between family members. If anything, logic suggests that the familial relationship between parent and child, and the statutory obligations parents have to their children, would seem to increase the elements of obligation central to a viable tort case. However, the limiting factor for family tort actions is not a defect in the legal theory or a failure of obligation or fact, but a natural reluctance by family members to sue one another. Therefore there are few tort actions commenced between child and parent.