Should I Worry About Third-hand Smoke Around My Baby?

My husband is an occasional cigarette smoker, maybe two or three per week. This bothers me deeply for multiple reasons, but what I’m really curious about is the potential impact on our baby, who is a little under 1 year old currently. He never smokes around him and claims that he always changes his shirt and washes his hands after smoking and before hugging/holding our baby. So I’m not worried about secondhand smoke, but now I’ve seen there’s something called third-hand smoke. Is this real in the data? The things I’ve found have mostly felt like, “Well, we assume this is an issue.” I’d love some more concrete data.
—Third-hand Concerns

Third-hand smoke: generally, this concern reflects the fact that when you smoke cigarettes, the byproducts from the tobacco smoke settle on surfaces (clothes, furniture, etc.), and this could be hazardous. Unlike secondhand smoke, which is widely understood to be harmful, we have much less evidence on the health effects of third-hand smoke. One study of adults in Spain showed that exposure to third-hand smoke, even without secondhand smoke exposure, generated detectable levels of cotinine (a marker of tobacco exposure) in saliva.

I will caution that this is only one study, and it’s quite difficult in the data to separate second- and third-hand smoke exposure. That is likely to be true in most studies, and the reality is that because we know there are large dangers in first- and secondhand smoke exposure, most policies just aim to lower smoking rates, without thinking too much about exactly why.

Based on theory, if your husband is changing his clothes and washing his hands after smoking, and not smoking in the house, the exposure for your child is likely to be extremely minimal. The most significant danger here, and I know you know this, is to your spouse.