Third-hand smoke: The hidden health hazard inside homes

The residue of second-hand smoke can linger for months or years on furniture, curtains, clothing and other surfaces.

- Yvette Van Der Eijk

For non-smokers, living with a smoker can be challenging. The desire to avoid being exposed to tobacco smoke clashes with the reluctance of the smoking family member to venture outside for every smoke break.

Many households end up with a compromise, for instance by restricting where in the home someone can smoke. As a result, despite the ban on smoking in most public places, many people remain exposed to second-hand smoke in their home.

A 2022 study published in the journal, Indoor Air, estimated that one in six adults in Singapore were exposed to second-hand smoke by a household member, as most smokers continued to smoke on the home premises.

The study also found that, in most cases, smokers were aware that their second-hand smoke harmed others and took steps to protect their family members.

Common strategies included smoking in designated parts of the home, smoking out of a window or balcony, opening windows to air out the room, or waiting for moments when they were alone at home.

These compromises may be well-intentioned but are not enough for many reasons. For one thing, they don't consider a further threat: That of third-hand smoke that breathing in second-hand smoke causes lung cancer. It is also linked to asthma, respiratory issues and heart disease, as well as cot death, ear infections, asthma and respiratory diseases in children.

A lesser known fact is that second-hand smoke is dangerous even at low levels. Studies have found that short-term exposure, and exposure at low levels, also increase the risk of heart disease and respiratory symptoms.

Second-hand smoke is especially dangerous for young children, as their bodies are smaller and take up a higher concentration of toxic chemicals.

Children also tend to be exposed to more second-hand smoke by family members as they spend more time in the home.