Researchers Study Smokers’ Perceptions of Thirdhand Smoke in Multiunit Housing

Researchers from the Department of Health and Exercise Science at the University of Oklahoma studied smokers’ understanding of what happens to smoke when cigarettes are smoked in multiunit housing, and their views about tobacco smoke residue in their apartment and surrounding units. The results of this study were published as a Letter to the Editor in the Journal of Alcohol and Drug Education.

August 2021

By Christopher Dunlap; Sarah Maness; Daniel Larson; Marshall Cheney

Dear Editor,
While tobacco use is restricted in public spaces such as workplaces, restaurants, and public housing, non-smokers’ exposure to environmental tobacco smoke can happen in the home, especially in multiunit housing, where no current national laws prohibit use, and tenants more frequently experience comparatively worse outcomes associated with environmental tobacco smoke exposure.
Thirdhand smoke, a toxic form of environmental tobacco smoke that settles on surfaces after smoking as dust or a residue, can exist in multiunit housing for months, even after cleaning surfaces. While often overshadowed by the more visible and publicized secondhand smoke (SHS) exposure symptoms, thirdhand smoke contains carcinogens which can be easily inhaled or absorbed dermally when touching contaminated surfaces. Smoke from smoking units can drift into non-smoking units, exposing non-smokers to both SHS and thirdhand smoke. While most smokers in multiunit housing are aware of the health effects of exposing others to SHS, most are not aware of thirdhand smoke and its health impacts on others, both within their own apartment and to others in their building.
This study examined current adult smokers’ knowledge of what happens to smoke inside of multiunit housing and how exposure to information about thirdhand smoke affects their intentions to relocate their smoking outdoors.
Adults who self-identified as smokers and lived in multiunit housing were recruited from Craigslist and screened for tobacco use while inside multiunit housing. To qualify for the one-on-one online interviews, participants needed to smoke inside of multiunit housing at least 16 out of the past 30 days and share either a ceiling, floor, or wall with another neighboring unit. Of the 158 potential participants who took the screening questionnaire, 78 qualified for the interview, and 30 participants completed the brief demographic questionnaire and online interview in Spring 2018.
The semi-structured interview questions addressed participant tobacco product use inside of multiunit housing, factors influencing where they choose to smoke, and beliefs about tobacco smoke spread and smoke residue/sediment both inside of their apartment and other attached units. Participants were then given an information sheet on thirdhand smoke from the Mayo Clinic. The fact sheet was written for a lay audience and included information about what thirdhand smoke was, how it was different from environmental tobacco smoke, how thirdhand smoke is toxic and can release chemicals into the air, how it surfaces inside the home like fabrics and hard surfaces, that children and nonsmoking adults may experience health risks when exposed to this substance, and how to remove it from potentially contaminated surfaces. After participants read the information sheet, they were asked for their reactions to the information about thirdhand smoke. Participants received a $10 e-gift card at the conclusion of the interview.
A codebook was developed from a review of the literature and an initial reading of the transcribed audio-recorded interviews. Three interviews were coded together by two coders (CD & MKC) then the remaining interviews were coded independently using NVivo v.11 (ICR=98.0%), coding differences were resolved, then the transcripts were analyzed for themes. Themes were identified both within and across codes then checked against the transcripts for confirming and disconfirming evidence. Representative quotes were then selected for each theme.
Participant Characteristics
Of the thirty smokers interviewed, the majority identified themselves as female, white, and having less than a college degree. Over one third (N=11) fell between the ages of 26 and 35 (mean age 38.3). Half of the participants (N=15) identified themselves as single, never married and two-thirds of participants (N=20) had no children in their homes. About half of the participants smoked half to one pack per day with most of the remaining participants reporting less than a half pack per day.
Themes from participant responses were grouped into knowledge about thirdhand smoke and reaction to educational material about thirdhand smoke.
Smokers Contextualize Cigarette Smoke with Smells
Almost all smokers said their indoor smoking was influenced by the smell of cigarettes, such as how much and when they smoke indoors or how the smell from their smoking affects others. Rather than potential health risks of environmental tobacco smoke exposure for non-smokers, smokers viewed the smell from smoking as an annoyance for non-smokers, similar to smelling neighbors’ cooking, the smell of marijuana, pet odors, or even just an old building. When asked the reason they could smell smoke long after they had finished smoking, several participants suggested the lingering smell of smoke was due to smoke still being in the air, while others compared the “musty” or “stale” smell to places like bars or heavily smoked-in rooms. However, only a few mentioned that the smell was likely coming from smoke that had become attached to either their clothes or surrounding surfaces.
Thirdhand smoke as Dirt rather than Toxicant
Several participants described the residue from their indoor smoking like dust or dirt which landed on surfaces and just made their home dirty or stained the walls. Participants mentioned using upholstery cleaners and bleaches to manually remove the residue on a regular basis. Most participants had never heard of thirdhand smoke prior to this study and if they indicated they did, they did not know of its potential toxicity.
Response to Information about Thirdhand Smoke
After reading through the fact sheet, participants had several reactions to the information. About half stated that they had no intention to stop smoking, seven said they still would smoke inside but that they would clean indoors more, and half intended to relocate their tobacco use outdoors.
Cleaning thirdhand smoke like Grime instead of Hazardous Material
Many still viewed thirdhand smoke more as dirt or grime instead of a toxicant even after reading information detailing how it was different and how it could affect health. Several respondents described thirdhand smoke as “gross” and planned to clean more frequently rather than prevent accumulation indoors pre-emptively by smoking outdoors. Responses indicated they would clean more frequently to reduce potential exposure to non-smokers who visited their apartment such as children.
No Intention to Change Behavior
Despite information about the risks of thirdhand smoke exposure to themselves and others, several in this study were not motivated to relocate their smoking outside of their apartment. Those less likely to express intent to relocate outside were those who primarily lived and associated with smokers and were unconcerned about the health risks associated with thirdhand smoke. These smokers were already aware of the risks of inhaling smoke so the idea of exhaled smoke landing on and re-releasing chemicals as thirdhand smoke seemed to be of little additional concern. A common sentiment was that non-smokers were entering a smoking residence and should accept the associated risks. These smokers felt the same for other residents in their housing unit, saying that if they were spending money to rent a unit, they could do what they wanted in that unit, including exposing other tenants to the harmful effects of environmental tobacco smoke and thirdhand smoke. While they were less concerned about protecting others, there was a more positive response to protect their personal belongings and monetary loss through smoke-related fines or deposit deductions for cleaning fees.
Environmental tobacco smoke exposure presents a major health risk for those living in multiunit housing, with one form, thirdhand smoke, affecting the health of non-smokers long after the act of smoking a cigarette. Even if smokers actively try to protect their non-smoking friends and family by not smoking in their presence, the release of chemicals from previous indoor smoking and the surface contamination from thirdhand smoke may undermine their efforts. These initial findings suggest that health messaging highlighting that non-smokers may be exposed to harmful effects of smoke even when not directly exposed to environmental tobacco smoke may prompt some indoor smokers in multiunit housing to smoke outside their unit. Those interviewed with children or grandchildren who were motivated to protect their offspring or at-risk housemates would likely be a good target for this form of messaging. However, health communication focused on thirdhand smoke should be carefully created, so that participants do not interpret thirdhand smoke as something that can be easily eliminated by extra cleaning of visibly affected surfaces such as walls.
Messaging focusing on protecting those at risk would likely not work on smokers who felt that it was their right to smoke inside a property that they currently pay to live in and that those who entered their apartments were accepting that risk. For smokers who may not be motivated to protect non-smokers, a focus on potential property damage or reduced security deposit refunds or cleaning fees for thirdhand smoke could be beneficial to motivate indoor smokers to move outside to smoke.
This study was limited in that the sole recruiting source was Craigslist. In addition, tobacco use and housing type were self-reported.
In summary, this study highlights a need to create health communication regarding smoking indoors that also includes information about the risks of exposure to thirdhand smoke for non-smokers, but in a way that does not frame frequent cleaning as a way to mitigate exposure risk from continued indoor tobacco use.