Aim: After many years of research into physical and chemical environmental noxious agents, in the field of social and environmental medicine attention is being paid increasingly to social environmental factors, summed up in the term “environmental justice”. The aim of the present paper is (1) to introduce a theoretical model for the determination of the influence of social environment on morbidity. For the city of Cologne, the model is (2) applied to the question of whether social environmental factors of relevance for health cumulate in specific neighbourhoods. Method: Analyses were made on an index based and factorial basis. 16 areas with differing social structures were selected in four districts of Cologne. These areas, which had together 90,000 inhabitants, were explored on foot to locate all the tobacco supply sources which were then mapped using the Geographic Information System (GIS) and the data linked with social indicators. Results: 364 tobacco supply sources were identified in the 16 areas. A significant correlation between the frequency of supervised tobacco supply sources (including cigarette vending machines in restaurants, newsagents/kiosks and service stations) and the social structure of the area was demonstrated: areas with a high proportion of foreign citizens, high levels of unemployment and persons on welfare had a significantly higher density of tobacco supply sources. Low income levels and limited living space are also associated with more sources of cigarettes. Similar statistical correlations were found for outdoor cigarette vending machines, but in this case they were not significant. Conclusions: This study shows — for the city of Cologne as an example — a statistical correlation between parameters of the sociostructural environment and a potential health hazard associated with the ready availability of cigarettes. Before we can analyse the complex association between social environment and morbidity further, however, data for many other such aspects must be provided by medical-environmental research.