The magazine of the UW School of Public Health

Integrating Public Health and Urban Planning

By Brendon Haggerty

Does neighborhood form predict physical activity? Can proximity to healthy food make a difference in diet? Will cooling centers save lives? Even for experts in public health and urban planning, it is challenging to trace the causal pathways that connect the built environment to a health determinant or outcome. 

Research that documents these causal pathways is of high value for the creation of effective public health policy. At least, this has been the experience of Clark County Public Health (CCPH), a local public health department in southwest Washington that has recently used research findings to guide comprehensive land use planning. 

In early 2011, CCPH partnered with the Community Planning Department of Clark County to inform the next update of the Clark County Comprehensive Growth Management Plan. The resulting document, known as The Growing Healthier Report, summarized research literature, described current conditions, and recommended policy changes. In June 2012, the Board of Clark County Commissioners endorsed The Growing Healthier Report as the document that would guide the update of the Comprehensive Growth Management Plan

The updated Comprehensive Growth Management Plan, to be completed by 2016, will include policies to improve health in eight topic areas that were identified in The Growing Healthier Report. These areas are housing, transportation, parks and open space, economic development, safety and social cohesion, access to food, environmental quality, and climate change.

In preparation for The Growing Healthier Report, CCPH provided a series of background reports summarizing research literature and data on Clark County for each of the eight topic areas. These background reports described pathways from policies, such as zoning or transit plans, to outcomes, such as physical activity and obesity. Drawing from published research, CCPH provided information to the Board of Clark County Commissioners that characterized the likelihood that various conditions in the local built environment were affecting health.

Integrating Research With Local Data

To provide the commissioners with compelling information, it was important that CCPH illustrate research findings using data from Clark County. Three examples of this approach are given below. 

Walkability index

Research shows that certain characteristics of urban form are associated with higher levels of physical activity. CCPH calculated a walkability index following a method developed by Lawrence Frank, James Sallis, and other leading researchers of health and urban form. The index combines measures of street network connectivity, land use mix, residential density, and building site coverage. A 2009 study conducted by Sallis and others found that living in neighborhoods with a higher walkability index was associated with meeting physical activity recommendations at least one more day per week. CCPH included a walkability index for Clark County in The Growing Healthier Report to show which areas of the county had a high need for pedestrian infrastructure or a high potential for walkability. This tool was especially useful given the lack of a reliable inventory of county-wide sidewalks.

Mapping the food environment

Research suggests that proximity to food influences a person’s diet. The availability of unhealthy food compared to the availability of healthy food is an important measure of the food environment. CCPH assessment staff worked with CCPH food inspectors to categorize each of the roughly 1,200 food retail establishments in Clark County. Categories included supermarkets, grocery stores, produce markets, farmers markets, convenience stores, fast food restaurants, and full-service restaurants. Staff then geocoded each establishment and mapped half-mile network buffers around each to estimate the population within walkable distance. They found that although about 41 percent of residents lived near a fast food restaurant or convenience store, only about 17 percent lived near a grocery store or supermarket. This knowledge helped identify areas of the county that were underserved by healthy food retailers. Potential policy changes that build on these findings include limiting fast food near schools or in areas with a high density of unhealthy food options. CCPH has already used these findings to implement a healthy corner store program.

Linking climate change modeling and health

Climate change is a public health emergency, and data show that increases in extreme heat, disease vectors, and severe weather events are already affecting the health of the residents of Clark County. To obtain this data, CCPH partnered with the Northwest Center for Public Health Practice (NWCPHP) at the University of Washington. (Downscale models of climate change are challenging to acquire, so local health jurisdictions can benefit from working with academic partners to obtain these models.)

Researchers working with NWCPHP analyzed historic data on morbidity and mortality in Clark County on extreme heat days. They found an increased risk of death and hospitalization on extreme heat days, especially among older age groups. Applying these findings to county-level climate models, researchers estimated by 2045, under a moderate warming scenario, Clark County can expect 19 deaths per summer due to climate change. Such information is useful to policy makers who could potentially allocate resources for climate change mitigation strategies such as building energy retrofits, as well as adaptation efforts such as designating cooling centers. 

Conclusion

Because it based its policy recommendations on current condition reports and research, The Growing Healthier Report became a powerful communication tool for advancing health promoting policies. In the months since the Board of County Commissioners acted to advance the recommendations in The Growing Healthier Report, community groups have drawn on the report’s findings for their advocacy activities. 

CCPH staff chose to conduct literature reviews internally rather than relying on off-the-shelf compilations completed by other organizations. This approach helped establish CCPH staff as local experts and gave staff members a common understanding of key issues. However, guidance documents from organizations such as the National Association of County and City Health Officials or the American Planning Association can be an ideal starting point for those seeking a greater familiarity with current research. 

Author

Brendon Haggerty, MURP, is an urban planner at Clark County Public Health in Vancouver, Washington.

Resources

  1. Sallis JF, Saelens BE, Frank LD, Conway TL, Slymen DJ, Cain KL, Chapman JE, Kerr J. Neighborhood built environment and income: examining multiple health outcomes. Soc Sci Med. 2009 Apr;68(7):1285-93.
  2. Active Living Research Briefs: www.activelivingresearch.org/toolsandresources/researchbrief
  3. ChangeLab Solutions: http://changelabsolutions.org/
  4. The Growing Healthier Report : www.clark.wa.gov/public-health/community/growing_healthy/documents.html