Achieving a healthy zoning policy in Baltimore: results of a health impact assessment of the TransForm Baltimore zoning code rewrite.

Objectives: The social determinants of health (SDH) include factors apart from genes and biology that affect population health. Zoning is an urban planning tool that influences neighborhood built environments. We describe the methods and results of a health impact assessment (HIA) of a rezoning effort in Baltimore, Maryland, called TransForm Baltimore. We highlight findings specific to physical activity, violent crime, and obesity.

Methods: We conducted a multistage HIA of TransForm Baltimore using HIA practice guidelines. Key informant interviews identified focus areas for the quantitative assessment. A literature review and a zoning code analysis evaluated potential impacts on neighborhood factors including physical activity, violent crime, and obesity. We estimated potential impacts in high- and low-poverty neighborhoods. The findings resulted in recommendations to improve the health-promoting potential of TransForm Baltimore.

Results: Mixed-use and transit-oriented development were key goals of TransForm Baltimore. Health impacts identified by stakeholders included walkability and healthy communities. For Baltimore residents, we estimated that (1) the percentage of people living in districts allowing mixed-use and off-premise alcohol outlets would nearly triple, (2) 18% would live in transit-oriented development zones, and (3) all residents would live in districts with new lighting and landscaping guidelines. Limiting the concentration of off-premise alcohol outlets represented an opportunity to address health promotion.

Conclusions: Changes to Baltimore's zoning code could improve population health including decreasing violent crime. HIAs are an important platform for applying SDH to public health practice. This HIA specifically linked municipal zoning policy with promoting healthier neighborhoods.