Leveraging Local Environmental Health Capacity to Inform Geospatial Assessment of Healthy Food Access in Contra Costa County, California

Diet is a major risk factor for the leading causes of morbidity and mortality among US adults. Inadequate access to healthy food has been cited as contributing to poor diets. While publicly available aggregate spatial metrics... [ view full abstract ]

Diet is a major risk factor for the leading causes of morbidity and mortality among US adults. Inadequate access to healthy food has been cited as contributing to poor diets. While publicly available aggregate spatial metrics of food access allow comparisons between zip codes or counties, geographic point-specific data are more useful for local decision-making organizations.

Our aim was to assess geographic healthy food availability in Contra Costa County, California using original data collected by county health inspectors, with a focus on areas with potential access barriers.

Inspectors collected data from all 797 retail food markets in the county using a short questionnaire on availability and quality of fresh foods. We matched surveys with data on markets’ square footage and acceptance of food assistance benefits. We mapped markets in ArcGIS 10.2 with publicly available data on demographics, poverty, food assistance usage, transportation, fast food outlets, and public schools.

The percentage of markets offering fresh foods increased with market size, from 11% of small markets (<2,000 sq ft) to 81% of large markets (>6,000 sq ft). The percentage of markets accepting food assistance benefits increased with market size, from 45% of small markets to 91% of large markets for Supplemental Nutrition Assistance Program benefits, and from 2% of small markets to 49% of large markets for Women, Infants, and Children benefits. Large markets comprised 56%, 49%, and 39% of markets in the high, middle, and low income zip code tertiles, respectively. The lowest income tertile had 8.1 convenience stores offering no produce per 10,000 residents, compared to 4.5 and 3.8 in the middle and high income tertiles, respectively.

These data show the value of using local health inspectors to assess healthy food availability. Our results can be shared with local government agencies and community groups for decision-making, research, and project planning.