Using GIS to evaluate the impact of the built environment surrounding transitional homeless shelters on their residents' tobacco use

Background: Tobacco use is an important health issue that disproportionally affects the homeless. Features of the built environment have been associated with tobacco use in other vulnerable populations, such as youth. Elements of the built environment are likely related to tobacco use among the homeless as well.

Methods: An environmental audit was conducted in and around 26 randomly selected shelters in Los Angeles County to assess environmental factors related to tobacco use. All shelters were geocoded using ArcGIS 10.1. A map based on street networks was created for each shelter to better understand the immediate neighborhood environment. With the assistance of shelter staff, a neighborhood assessment using a GPS device was conducted within a 1000 foot radius around each shelter, geocoding possible environmental influences such as tobacco retailers and concentrations of cigarette butts.

Results: Initial analyses of the environmental audits indicate the need for increased signage on shelter property restricting tobacco use. Neighborhood assessments varied greatly based on geographical location of the shelter, urban/rural areas, and land use zoning. More retailers within a 1000 foot radius were found around urban shelters than around rural shelters. Multilevel analyses will include tobacco use at the shelter resident level in relation to environmental and neighborhood assessments.

Conclusions: This research will help us to better understand environmental determinants of tobacco use among the homeless that might contribute to their high rates of tobacco use. Findings can inform policy changes around creating healthier neighborhood and shelter environments and ultimately help reduce health disparities.