The smoking routines of spouses during the marriage are also a consideration. In these cases, the courts have tended to treat the issue under a "change in circumstances" analysis. Under this standard, courts have dismissed the issue of ETS where the smoking parent smoked before the divorce. Thus, citing the lack of changed circumstances, in Cooley v. Cooley, 643 So.2d 408 (La. Ct. App. 1994, the court refused to modify custody because nothing in the record indicated that the custodial parent did not smoke prior to the divorce.

Notwithstanding the change in circumstance, there would appear to be strong arguments to consider ETS in some cases regardless of the previous smoking history of the parties. For example, where there is a clear and present danger to the child, the state's responsibility under the doctrine of parens patriae may require action notwithstanding a lack of changed circumstances, especially where clear harm to the child can be demonstrated and where the nexus between that harm and ETS exists. Courts may come to the conclusion that the issue of whether a parent smoked during the marriage is not a basis to avoid taking action to protect the child.

When confronted with the situation of a child suffering harm from exposure to ETS, the courts have employed one of two remedies. The obvious and most drastic is to award custody to the non-smoking parent. The far more common remedy is to craft restrictions on the right of the smoking parent to smoke near the child.

Regardless of the nature of the restriction, these cases often result in problems with monitoring and enforcement. Challenges that a party may have violated a smoking restriction often require a time-consuming hearing to determine disputed facts and allegations. When fact witnesses are not available, expert analysis may be necessary. In these cases, medical reports regarding the health of the child, the smoke content of the child's clothing, or the air quality in the custodial parent's home may be important in demonstrating a violation of the smoking restrictions.

There are cases where courts have modified or reversed a custody arrangement based on cigarette smoking. In Aubuchon v. Aubuchon, 913 P.2d 221 (Kan. Ct App. 1996), a change of custody was deemed the appropriate solution after the trial court found that the custodial parent's smoking "had harmed the children." In Badeaux v. Badeaux, 541 So.2d 301 (La. Ct. App. 1989), the court found a custodial parent's smoking to be sufficient reason to modify a joint custody arrangement by curtailing the time the child may spend with the smoking parent. In most cases, however, smoking results in a change of custody only where there is clear evidence that the smoking parent is ignoring either a court order or a doctor's advice to refrain from smoking in the presence of the child. In Mitchell v. Mitchell, 1991 WL 63674 at *3 (Tenn. App. 1991), the courts concluded that smoking in the presence of a asthmatic child in contradiction of a doctor's advise "was strong evidence of a lack of proper concern for the welfare of the child."