Walking Behavior of Older Adults and Air Pollution: The Contribution of the Built Environment

Although an increase in walking is recommended to improve physical activity and public health, especially among older adults, the frequency of outdoor pedestrian activities, including walking, should be reduced when there is increased air pollution. There is limited understanding of the inter-relationships between two research fields, namely, older adults walking behavior and air pollution. This study investigates these factors and identifies their relationships with associated built environment factors. More than 200 peer-reviewed journal articles that met the selection criteria were analyzed. The factors pertaining to air pollution in the built environment were classified based on the scale of the urban environment. Comparing the built environment factors related to both fields of study, several common features such as the type of street enclosure (urban spatial), sky view factor (urban spatial), percentage of front gardens (urban design), and land use patterns were identified. Furthermore, we found that it is important to understand how the subjective/objective measures of the urban-design-related factors identified on the street are linked to air pollution at both street and neighborhood scales. A wide range of urban vegetation factors (pattern, size, and density) in both fields of study at a street scale were also identified. These inter-relationships need to be examined by future studies to get a clearer picture of the factors which might improve walking behavior among older adults while reducing the air pollution in urban environments.