Introduction

This study sought to provide essential tobacco control tools by testing the reliability and validity of new self-report scales developed to assess thirdhand smoke (THS) (ie, toxic tobacco residue) related knowledge, attitudes, and behavior (KAB).

Aims and methods

Items for the KAB scales were adapted from established secondhand smoke (SHS) measures, reviewed to support face validity, and tested in a longitudinal online survey evaluating THS health messages. Participants were California adults at risk of THS exposure. For 7 months, the three KAB scales were completed monthly, and data from the first (n = 1086), third (n = 315), and seventh (n = 301) month surveys were used in these analyses.

Results

All three scales demonstrated consistent reliability and single-factor loading at all three timepoints for knowledge (αrange: .87-.90), attitude (αrange: .84-.87), and behavior (αrange: .80-.86). Similarly, analyses supported scale convergent validity (scale correlations rrange: .45-.85; all p values <.001), discriminant validity between smokers and nonsmokers (knowledge Cohen's drange: .57-.61, all p values <.001; attitude Cohen's drange: .78-.82, all p values <.001; behavior Cohen's drange: .90-.99, all p values <.001), and predictive validity (range R2KAB: .41-.48; all p values <.001).

Conclusions

KAB scales about THS provide new opportunities for tobacco control advocates and scholars to identify gaps in knowledge, misperceptions, and obstacles to behavior change in order to guide the design of novel tobacco control policies and interventions.

Implications

Numerous scales have been vetted as reliable and valid measures for assessing SHS-related KABs. Currently, standard measures of THS KABs are not available. This study tested three THS scales to fill this gap. The present findings provide tobacco control advocates, scholars, and practitioners tools for assessing KABs related to THS. This information is critical to development, implementation, and evaluation of novel tobacco control strategies.

The US Food and Drug Administration (FDA) applies the Population Health Standard in tobacco product review processes by weighing anticipated health benefits against risks associated with a given commercial tobacco product at the population level. However, systemic racism (ie, discriminatory policies and practices) contributes to an inequitable distribution of tobacco-related health benefits and risks between white and Black/African Americans at the population level. Therefore, Black-centered, antiracist data standards for tobacco product review processes are needed to achieve racial equity and social justice in US tobacco control policy. Regardless of whether FDA implements such data standards, non-industry tobacco scientists should prioritise producing and disseminating Black-centred data relevant to FDA's regulatory authority. We describe how systemic racism contributes to disparities in tobacco-related outcomes and why these disparities are relevant for population-level risk assessments, then discuss four possible options for Black-centred data standards relevant to tobacco product review processes.

Despite a growing body of research outlining the harms of thirdhand smoke (THS), the public remains generally unaware of risks and exposure routes. This project built on past tobacco prevention campaigns and the tenants of McGuire's input-output model to implement and evaluate a seven-month Facebook-disseminated campaign seeking to improve THS awareness among California adults (n = 1087). Multilinear regression showed that THS-related knowledge (χ²[6] = 19.31, p < .01), attitude (χ²[6] = 13.88, p < .05), and efficacy (χ²[6] = 13.81, p < .05) significantly increased by the campaign's end, with messages highlighting children's health (r = .110, p < .05), pets (r = .145, p < .01), and dust reservoirs (r = .144, p < .01) as the most persuasive. Path analysis modeling found campaign recall to be associated with changes in knowledge (β = .161, p < .01), which predicated attitude change (β = .614, p < .001) and, in turn, behavior change (β = .149, p < .05). Findings suggest social media campaigns should continue to educate diverse populations about new tobacco risks and that tobacco control advocates should consider integrating educational THS messages.

Starting in the 1970s, individuals, businesses and the public have increasingly benefited from policies prohibiting smoking indoors, saving thousands of lives and billions of dollars in healthcare expenditures. Smokefree policies to protect against secondhand smoke exposure, however, do not fully protect the public from the persistent and toxic chemical residues from tobacco smoke (also known as thirdhand smoke) that linger in indoor environments for years after smoking stops. Nor do these policies address the economic costs that individuals, businesses and the public bear in their attempts to remediate this toxic residue. We discuss policy-relevant differences between secondhand smoke and thirdhand smoke exposure: persistent pollutant reservoirs, pollutant transport, routes of exposure, the time gap between initial cause and effect, and remediation and disposal. We examine four policy considerations to better protect the public from involuntary exposure to tobacco smoke pollutants from all sources. We call for (a) redefining smokefree as free of tobacco smoke pollutants from secondhand and thirdhand smoke; (b) eliminating exemptions to comprehensive smoking bans; (c) identifying indoor environments with significant thirdhand smoke reservoirs; and (d) remediating thirdhand smoke. We use the case of California as an example of how secondhand smoke-protective laws may be strengthened to encompass thirdhand smoke protections. The health risks and economic costs of thirdhand smoke require that smokefree policies, environmental protections, real estate and rental disclosure policies, tenant protections, and consumer protection laws be strengthened to ensure that the public is fully protected from and informed about the risks of thirdhand smoke exposure.