Smoke-free buildings that have policies requiring residents to butt out in both common and private areas of a property are effective in reducing exposure to harmful airborne contaminants in multi-unit housing, according to a new study published in Nicotine & Tobacco Research.
Comparison of Indoor Air Quality in Smoke-Permitted and Smoke-Free Multiunit Housing: Findings From the Boston Housing Authority built on previous evidence of smoke transfer between smoking and non-smoking units. Notably, the study found that median household levels of fine particulate matter — an environmental marker for second-hand smoke — were about 40 per cent lower in buildings with broad bans on smoking (4.8 versus 8.1 micrograms per cubic metre).
“It’s (smoke transfer) not something that nobody ever knew about before, but it’s demonstrated here again, and the fact that the smoking policy of the building is associated with aerosol levels is supportive of having [building-wide smoke-free] policies,” said lead study author Elizabeth Russo, MD, Boston Public Health Commission, Research and Evaluation Office.
The study followed a September, 2012 transition at the Boston Housing Authority, during which the agency implemented a smoke-free policy across its portfolio of buildings. The policy prohibited smoking anywhere inside the property and within a certain distance of the property outside, including on balconies and terraces.
The move provided an opportunity to compare the differences between smoking and non-smoking buildings, said Russo.
The study tested environmental markers for second-hand smoke in five different developments, including in 15 households with resident smokers and 17 households without resident smokers as well as in common areas and outdoors. Researchers measured fine particulate matter with aerosol monitors and used nicotine monitors to confirm that the matter was mostly attributable to tobacco smoke.
The building types under study ranged from three-storey walk-up to mid-rise to high-rise. One caveat is that air transfer partly depends on a building’s characteristics, Russo said. But, she added, the building populations shared common characteristics.
Public housing residents are a vulnerable population, with higher rates of both smoking and asthma, making them especially prone to the health concerns posed by second-hand smoke. The study pointed to the Surgeon General’s warning that second-hand smoke can cause disease and premature death in non-smokers, with any level of exposure bearing risk.
Resident smokers enjoyed the most dramatic drop in particulate matter levels in smoke-free buildings, with their exposure halved (14.3 versus seven micrograms per cubic metre). Households without resident smokers still benefitted from a decrease in particulate matter levels of about 20 per cent compared to those living in buildings where smoking is permitted.
During hours when smoking residents reported smoking, particulate matters rose in both the smoking resident’s unit and the adjacent non-smoking resident’s unit. The main difference was that the increase spiked higher and dropped faster in the smoking resident’s unit than in the non-smoking resident’s unit.
Particulate matter levels also rose in non-adjacent units and common areas during hours when smoking was reported in a smoking resident’s unit, but to a lesser extent.
“This is just further evidence that having smoking areas within the same building and non-smoking areas within the same building does not confer the same level of protection as having an entire building be smoke-free,” said Russo.
The study’s release followed a recommendation adopted by Toronto City Council in July that the building industry be encouraged to designate either smoke-free condominiums or smoke-free floors or zones within condominiums.
Michelle Ervin is the editor of CondoBusiness.