Objective Behavioural interventions, such as smoke-free signage, are used to support air quality in public outdoor spaces that are not protected by a smoke-free policy, such as states with preemptive clause legislation. However, there is little evidence of the effectiveness of these interventions. This paper is an evaluation of whether smoke-free signage posted in public parks altered smoking behaviours of park patrons.
Methods A time-series quasi-experimental design was used. Cigarette butts were collected at the same day and time every week in ten amenities within four parks in 2011. Each park completed a baseline period until a stable trend emerged at six weeks, then received smoke-free signage for the six week intervention period. There were 1684 cigarette butts collected during baseline and 1008 collected during the intervention phase.
Findings Wilcoxon signed-rank test demonstrated that smoking at seven out of ten amenities decreased and the overall decrease was significant at p=0.028. Individual parks and amenities grouped by type did not experience a statistically significant change. A neighbourhood median income trend was visually discovered, revealing that as income increased, there was a greater decrease in cigarette butts.
Conclusions This study provides evidence on the impact of smoke-free signage not supported by local ordinance in public parks using a reproducible measure. States, especially those with a preemptive clause legislation, may benefit from incorporating smoke-free signage in public areas to protect community members from exposure to tobacco smoke, reduce littering, and denormalise smoking.
- Secondhand smoke
- Socioeconomic status
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Involuntary exposure to secondhand smoke causes more than 41 000 annual deaths in the USA.1 There is no safe level of secondhand smoke exposure and outdoor exposure to tobacco smoke can be comparable to indoor concentrations.1 2 Smoke-free policies for public indoor spaces protect non-smokers from involuntary smoke exposure, decrease daily tobacco consumption, encourage smokers to quit, increase successful quit attempts, and decrease initiation of adolescent smoking.1 3
Smoke-free policies are a successful strategy to protect non-smokers, yet there is minimal research on methods to reduce outdoor smoking where policy restrictions may not be possible.3–6 Smoking bans in public parks across the USA are increasing and as of January 2017, there were 1369 municipalities with smoke-free park laws.7 However, some communities are unable to enact policies that create smoke-free outdoor spaces. Preemptive clause legislation restricts municipalities from sanctioning laws stricter than the state law.8 Florida is one of thirteen states unable to pass local laws restricting tobacco use beyond that of the state level, making it an ideal site for this study.9
This investigation evaluated whether unenforceable smoke-free signage would alter smoking behaviours among park patrons. Point-of-decision prompts, such as motivational signs used in physical activity research, employ health-promoting messages to positively influence behaviour change.10–12 One study researched compliance of a college campus smoking ban using a multicomponent approach, which included signage.13 Results suggested that the use of multiple components increased compliance, but it was unknown which component was most responsible for the outcome.13
This study, completed in 2011, used a time-series quasi-experimental design to investigate the usefulness of non-enforced signage. Cigarette butts were collected within picnic pavilion, playground, and restroom amenities every week on the same day and time for twelve weeks unless dangerous weather prohibited collection. Cigarette butts were defined as the butt of a tobacco product including cigarettes, cigarillos, and cigars. The University of Florida Institutional Review Board provided exempt status of the research protocol (2011 U-0671).
Smoke-free sign development
Signs were developed through partnering with staff from the Alachua County Health Department, the City of Gainesville Parks, Recreation and Cultural Affairs (PRCA), and Tobacco Free Alachua. Literature on smoke-free signage was explored to determine the best phrasing for this study.14 Final phrasing was approved by all partners (figure 1).
A sampling frame of all city parks (n=39) was received from the City of Gainesville PRCA. Each park was observed to visually confirm amenity types, determine high-usage amenities in need of smoke-free signage, and establish sign placement. Eight parks, chosen in neighbourhoods outside of student housing areas, were matched and randomly assigned to the intervention or matched control; however, signs were erroneously placed in intervention parks at week one. Therefore, only the four matched control parks were used and served as their own control for this study.
Collection zones and measurements
Volunteers were trained at a non-study park on proper measurement techniques and cigarette butt collection. Collection zones extended 25 feet from amenities with minor adjustments due to different physical layouts.15 Measuring tapes were used to create the violation zone around each amenity and cones were placed to mark boundary lines during collection. Prior to collecting data, parks were cleaned of cigarettes within each boundary area. Data were collected until a baseline trend was established at six weeks, then smoke-free signs were placed in each park and data were collected for another six weeks. Only cigarette butts within the boundary areas were collected. To increase reliability, amenities were combed by several research team members. Cigarette butts were placed into Ziploc bags and double counted by different research staff, the bag was labelled, and data were electronically recorded.
Neighbourhood median income
Approximate median income and population size were received from the city. Median income and decrease in cigarette butts were visually examined by neighbourhood for trends.
The Wilcoxon signed-rank test was used to evaluate changes between amount of cigarette butts collected during the baseline and intervention periods to assess whether signage had any effect in reducing the amount of cigarette butts. Means were compared from baseline and intervention to determine if all park amenities (n=10) experienced a statistically significant change in cigarette butts. Means were also compared from baseline and intervention for individual parks and by grouped park amenity (playgrounds n=4, picnic pavilions n=4, and restrooms n=2); for example, the baseline and intervention means of collected data from all playgrounds were compared.
Over the span of twelve weeks, 2692 cigarette butts were collected from four parks. There were 1684 cigarette butts collected during the baseline period and 1008 were collected throughout the intervention period. Most cigarette butts were found at picnic pavilions (n=4, 64.78%), followed by playgrounds (n=4, 28.49%), and restrooms (n=2, 6.72%). All parks experienced a decrease in cigarette butts from baseline to intervention. Mean substitution was used for 6 out of 48 weekly observations (weeks 6, 7, and 12) due to bad thunderstorms. Cigarette butts were not collected for these weeks and may have increased the number of cigarette butts found in the following week. Although a limitation to the study, we assume foot traffic decreased during this time, thus smoking was also reduced, and it occurred across all parks.
Seven of the ten park amenities experienced a decline in cigarette butts after smoke-free signs were placed. Wilcoxon signed-rank test indicated the intervention was associated with a statistically significant decrease (p=0.028) in cigarette butts from baseline to intervention for all park amenities (n=10). Specific park amenities were combined and compared from baseline to intervention (playgrounds n=4; picnic pavilions n=4; restrooms n=2), but they did not have a statistically significant decrease in cigarette butts. Individual parks, which compared baseline and intervention means from amenities within the park, were not statistically significant.
We believed the presence of smoke-free signs would decrease smoking in parks. The intervention was associated with a statistically significant decrease in cigarette butts. Despite the decrease, individual parks or amenities grouped by type were not statistically significant, which may be due to low power. However, an income-related trend was visually discovered (figure 2).
Parks in neighbourhoods with higher income levels had fewer cigarette butts after the intervention and Northeast park was approaching marginal significance (p=0.109). Lower income neighbourhood parks showed minimal decrease and three of the five amenities experienced an increase. While the median income for Possum park was highest, the greatest percent decrease occurred in Northeast park, which may be due to a larger neighbourhood population size. However, larger neighbourhood size did not decrease cigarette butts in lower income parks.
Individuals with low socioeconomic status (SES) have higher smoking rates than the general population due to increased structural and psychosocial barriers to smoking cessation.16 17 Cessation barriers among low SES groups include nicotine addiction, stress management, lack of support or resources to quit, social acceptability, and social norms.17 Low SES groups experience weak social norms that favour quitting.18 Social norms regarding non-smoking may be weaker than smoker group-specific norms that reinforce smoking behaviours in this population, which may explain why parks in low-income neighbourhoods experienced less change than higher income neighbourhood parks.19 However, smoke-free signs might make smokers feel uncomfortable due to social norms that promote compliance.
Smoke-free signs in this study aimed to modify barriers at the social and community level through denormalisation of smoking social acceptability and positive-smoking social norms. Additional media delivery channels, such as local television, newspaper, and other print materials, may bolster signage effects to increase the denormalisation effort.20 Furthermore, as smoking is denormalised, signs might serve as a cue to empower non-smokers to request smokers to stop smoking.21 Individuals in higher income neighbourhood parks with fewer structural barriers might have increased motivation to alter their smoking behaviours due to changing social norms and peer pressure from non-smokers.
There could also be a youth and young adult factor that differs by neighbourhood income. Higher income neighbourhood parks may have better lighting, security fences, or park maintenance staff than parks in low-income areas. Parks in lower income neighbourhoods may be a place where youth feel they can use tobacco products and other substances without consequence.22 Signs with messaging to refrain from smoking to protect children may be deemed irrelevant because youth may attend the park after dark. Signs specifically targeting this population should be tested.
Smoke-free signs are a potential way to reduce outdoor smoking in public areas, decrease littering, and denormalise smoking.6 States with preemptive clause legislation may benefit from smoke-free signs to reduce smoking and protect the public from secondhand smoke emissions, although it is unknown if these results are generalisable to other cities. The use of cigarette butts as the primary data source is a limitation. Researchers would benefit by using supplementary methods, such as observations and key informant interviews, to support findings. It is also possible that signage effects may decline over time.23 24 Future studies should analyse long-term effects of signage, compare cities in states with and without preemption to discover differences in signage effects, and investigate income-related trends in response to signage.
What this paper adds
Previous research suggests that signs which employ health-promoting messages positively influence behaviour change.
Research using smoke-free signage as part of a multicomponent approach to a college campus smoking ban was found to increase compliance.
This study needed to be done because research regarding smoke-free preemption laws is limited and unenforceable smoke-free signs as a method to reduce smoking in public parks had not been tested.
Results suggest that states with preemptive clause legislation can benefit from smoke-free signs to reduce smoking and protect the public from secondhand smoke emissions.
Results suggest that smoke-free signs can socially denormalise tobacco use and support cessation.
Contributors HNP is responsible for the overall content as guarantor. She completed this research for her master’s thesis. She trained volunteers, collected and stored all data, analysed data, created tables and figures, successfully defended her master thesis and wrote this entire manuscript. SBP was on Heather Platter’s Thesis Committee. He had the idea for the study due to his position at the Alachua County Health Department, Tobacco Free Alachua. He provided guidance and support to HNP throughout her master thesis. He also proof-read and edited the submitted manuscript.
Competing interests None declared.
Patient consent None.
Provenance and peer review Not commissioned; externally peer reviewed.
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