Analysing the tobacco environment through a geographic approachlessons and implications from gis-based research

Résumé

Tobacco consumption is one of the main causes of premature morbidity and mortality, causing more than 8 million deaths each year in the World. Similarly, tobacco products and their use are highly present in our physical and social environment. In the last years, there has been an increased knowledge of how the tobacco environment, through many channels and forms, may affect smoking behaviours among the population. In addition, other articles highlighted several environmental damages from tobacco production, distribution, and disposal. Several types of methods have been developed to approach the tobacco environment. Equally, different policy regulations have been enacted to reduce the availability, accessibility, visibility, and presence of tobacco in the environment. In this context, the use of Geographic Information Systems (GIS) has emerged as a novel framework to monitor and analyse the presence of tobacco in the environment, smoking related behaviours and the compliance and effectiveness of the current tobacco control policies. This dissertation represents an extensive proposal of how GIS may assist the study of the tobacco environment. The studies presented in this research were conducted in the city of Madrid, Spain, which was used as a model of high-populated European urban area. In addition, Spanish regulations on tobacco control present some interesting particularities in comparison with the policies enacted in other jurisdictions, since the geographic distribution of tobacco stores is limited by a minimum distance of 150 metres between them. Four scientific articles emanated from respective studies. In each of these documents are presented the methods and results that allowed for the achievement of the four specific objectives outlined above. In the paper 1, we identified forty articles using density and proximity measures to approach the tobacco environment. Different types of density and proximity measures were described. 47.4% of density calculations were based on simple counts (i.e. number of outlets within an area). Kernel Density Estimations and other measures weighted by spatial unit (i.e. outlets/sq km), person (i.e. outlets/inhabitant), and road length (i.e. outlets/road kilometres) were identified. 81.3% of the articles which assessed proximity to tobacco outlets used length distances estimated through the street network. Most of the articles using density measures found that higher density values were mostly associated with higher smoking prevalence (n=76.2%), greater tobacco use and smoking initiation (n=64.3%); and lower cessation outcomes (n=84.6%). Proximity measures were not associated with any smoking outcome except with cessation: higher proximity values were related to lower cessation rates (n=62.5%). The studies 2 and 3 show maps about the smokers’ visibility and the presence of discarded cigarette butts across the entire city of Madrid, respectively. In both articles, hospitality venues (bars, restaurants, cafés, and pubs) and public transportation stops were the public places with the highest concentrations of smokers and cigarette butts. They were followed by playgrounds, the entrances to educational venues and entrances to supermarkets or food stores. Signs of tobacco consumption were also identified in the surrounding areas of benches in parks, green spaces, streets, or other public pathways. Our findings evidenced an unequal distribution of both visibility of smokers and presence of cigarette but littering throughout the study area. The visibility and presence of these signs of tobacco consumption were higher in the central districts of the city (with a high density of hospitality venues, public transportation stops, and retail shops), in comparison to the peripheral districts (with larger green areas and residential or industrial land uses). The validation analyses presented a high correlation between our estimations and objective values of visibility of smokers (study 2, R=0.845, p=<0.001) and density of cigarette butts (study 3, R=0.784, p=<0.001). Our fourth study underlined a high availability of and accessibility to tobacco stores in Madrid. 5.3% of tobacco stores were within 150 metres of each other from which 76% did not meet the regulation sales threshold enacted to justify the proximity between tobacco stores in Spain. The uncompliant stores were in areas with lower proportion of young population (<15 years) and higher proportion of people with university-level education. Additionally, 75% of the whole tobacco stores in Madrid were located closer than 300 metres to an educational centre. No differences were identified by areal sociodemographic and economic characteristics by the tobacco stores distance to schools. This dissertation describes how GIS may represent a useful tool to measure the tobacco environment from multiple approaches. The studies included in this project discuss different GIS-based methods to study the availability of and accessibility to tobacco retailers, the visibility and/or presence of signs of tobacco consumption in public spaces, and to analyse the compliance and the effectiveness of the tobacco market regulations in Spain. The findings obtained from this research present several methodological implications to improve future tobacco exposure measures based on tobacco retail density or proximity calculations or estimations of the visibility or presence of different types of sings of tobacco consumption. In this sense, the methodological developments conducted in the studies 2 and 3 represent innovative applications of GIS tools which have not been extensively explored in tobacco environment research yet. Furthermore, the results exposed in this dissertation may pose further policy regulations to reduce the number of tobacco retailers and mitigate the visibility of smoking behaviours and the cigarette butt pollution in the environment.