Secondhand smoke infiltration in multiunit housing continues to pose a critical yet often overlooked public health threat in the United States and Canada. This issue affects nearly half of all residents in such settings, exposing millions of nonsmokers to health hazards despite many implementing smoke-free policies within their own homes. According to federal health authorities, secondhand smoke infiltration poses serious risks to the well-being of children and adults, yet no state prohibits smoking in privately owned multiunit housing. Only a minimal number of municipalities—just a fraction out of thousands—have enacted local laws mandating smoke-free environments in private units. This pressing public health challenge has led to calls for policy intervention to protect residents from involuntary exposure to harmful airborne toxins from neighboring units.

This comprehensive study, conducted by Physicist James Repace from Repace Associates, Inc. and published in Indoor Environments, highlights the health impacts reported by nonsmoking residents across a variety of apartments in the United States and Canada, with smoke infiltration confirmed by nicotine monitors. The study’s findings illustrate the breadth of health issues caused by secondhand smoke, which included symptoms such as eye, nose, and throat irritation, dizziness, breathing difficulties, and asthmatic attacks. “Many of these residents experienced serious symptoms that led to medical consultations and even hospitalizations,” Physicist Repace commented. These findings underline the ineffectiveness of measures like sealing gaps, air cleaning, and increased ventilation in eliminating smoke infiltration.

Physicist Repace’s investigation spanned nearly two decades, employing passive nicotine monitors to measure secondhand smoke infiltration levels in affected homes. Nonsmokers faced nicotine concentrations in their units that, while seeming low, represent levels that add up to significant toxic exposure when prolonged. The toxic components in secondhand smoke, which include numerous harmful chemicals, produce cumulative health effects. For example, nicotine was found to accumulate unpredictably on surfaces over time, often building up in ways that surprise residents. These insights align with the U.S. Air Quality Index’s classifications, where secondhand smoke levels in smokers’ apartments translate to very unhealthy to hazardous conditions, underscoring the need for more effective measures to safeguard nonsmokers in multiunit housing.

The study further identified that despite implementing remedial actions such as sealing openings, using air filters, and relying on ventilation systems, residents continued to experience adverse health effects. This is primarily due to the porous nature of building materials, which allows smoke to diffuse through tiny openings driven by pressure differences between units, wind pressures, and the “chimney effect” where cooler air infiltrates lower levels, rises as it warms, and escapes at upper levels. Physicist Repace observed, “Most building management and owners are unaware of the extent of smoke infiltration, leaving nonsmokers unprotected.” Many nonsmokers, unable to mitigate the issue, resorted to litigation for relief, though only a limited number of cases led to a satisfactory outcome.

Adding to the complexity, recent legalization of marijuana in certain regions has led to parallel concerns over marijuana smoke infiltration, which appears to affect nonsmokers similarly. A few individuals in this study reported issues with marijuana smoke, confirmed through THC residue testing, and experienced comparable symptoms to those caused by tobacco smoke. As Physicist Repace ‘s findings reveal, this growing trend increases the urgency for comprehensive smoke-free policies to protect the health of nonsmoking residents.

This research ultimately highlights the far-reaching and often severe consequences of secondhand smoke in multiunit housing, revealing that without robust smoke-free policies, nonsmoking residents are vulnerable to persistent and involuntary exposure to harmful air pollutants. Physicist Repace’s work advocates that building managers and owners should be better educated and proactive in implementing smoke-free policies to ensure the health and safety of all residents. Until then, the study emphasizes the need for policymakers and public health advocates to recognize and address the urgent need for legal measures to prevent involuntary secondhand smoke exposure in multiunit housing.

Journal Reference

Repace, J.L. “Secondhand smoke infiltration in multiunit housing: Health effects and nicotine levels.” Indoor Environments, 2024. DOI: https://doi.org/10.1016/j.indenv.2024.100013

About the Author

James Repace is a secondhand smoke consultant, and is a retired US EPA senior air policy analyst and staff scientist. He has published more than 100 scientific papers and research reports, 89 them on secondhand smoke. His research and policy efforts facilitated workplace smoking bans in the USA and abroad.
He has received The Surgeon General’s Medallion, awards from the American Public Health Association, the Flight Attendant Medical Research Institute, the Robert Wood Johnson Foundation, and the International Society of Exposure Science. He has served as a Visiting Asst. Clinical Professor at the Tufts University School of Medicine, and as a Consultant to the Stanford University Department of Civil and
Environmental Engineering.
He has been an expert witness in more than 5 dozen secondhand smoke legal cases. He has given numerous radio, television, and newspaper interviews and commentaries worldwide. Previously, he served as a research physicist at the US Naval Research Laboratory, a research associate at RCA’s David Sarnoff Laboratory, and was health physicist in two New York area hospitals.
He has published a memoir, Enemy No. 1, Waging The War on Secondhand Smoke, available as an Ebook and Paperback on Amazon.com. His latest paper is Secondhand Smoke In Multiunit Housing, Health Effects and Nicotine Levels, in the
journal Indoor Environments 1: 2024.100013.

Repace is the author of the book, Enemy No. 1, Waging The War On Secondhand Smoke, on Amazon Books