Is walkability healthy for all? Using the National Environmental Database to examine equity in the environmental health characteristics of pedestrian-supportive neighborhoods in the U.S.

BACKGROUND

Marginalized populations in the U.S. often live in dense urban areas, which could promote active travel and health. However, while compactness can support walkability, it can also create exposure to pollution, noise, injury risk, and urban heat islands. These exposures may be higher for marginalized groups, creating systematic "walkability-related" risks.

OBJECTIVES

We evaluated relationships between walkability, health-related environmental exposures, and social vulnerability, asking: (1) How are sociodemographic groups sorted across space with respect to walkability? (2) Do the environmental health correlates of walkability vary by social vulnerability?

METHODS

We compiled block group-level data for the 30 largest U.S. metropolitan areas. We measured walkability using the National Walkability Index; social vulnerability using indicators of race/ethnicity and socioeconomic status; and environmental exposures using PM, pedestrian fatalities, noise, and tree coverage. We used multilevel mixed-effects regressions to predict (1) walkability as a function of vulnerability and (2) each environmental exposure as a function of the cross-tabulation between walkability and vulnerability.

RESULTS

Higher walkability was associated with higher vulnerability. Compared to highly walkable block groups with low vulnerability, those with high vulnerability had higher PM and noise levels and lower tree coverage. These differences were even more pronounced among block groups with low walkability, suggesting pervasive inequities.

DISCUSSION

While marginalized groups often live in more walkable places, the "high" walkability to which they are exposed carries greater environmental risks than for privileged populations. Our findings illustrate the importance of mitigating environmental burdens that could dampen the health benefits of walkability in marginalized communities.