Built Environment - PA

Built Environment and the Socio-Ecological Model (SEM)

• The built environment (human-made surroundings) is the setting for human activity and influences health behaviors, like physical activity (PA).

• SEM: Explains how multiple levels impact health behaviors.

The Three Ds of Urban Planning

• Density, Diversity, and Design are core concepts.

• Density: Amount of activity in an area (housing, businesses, parks).

• Diversity: Different land uses in close proximity (residential, commercial, parks).

• Design: How land uses are connected (street patterns, connectivity).

Density

• High density means many people and land uses in a compact area (e.g., bustling urban centers).

Diversity

• A mix of close land uses increases PA by providing more walkable/cyclable destinations.

Design

• Street patterns and connectivity matter; well-connected designs support diverse land uses.

• Crow-fly buffer vs. road network: Car routes vary based on street connectivity.

• Sprawl: Dispersed, low-density development with rigid separation of uses.

• Smart Growth: Compact, connected, walkable communities to reduce sprawl.

• Urban design features for PA: benches, lighting, traffic calming, accessible parking strategies.

• Public transport and intersection density boost active transport.

Examples from Urban Design and Active Transport

• Benches, lighting, crosswalks, traffic calming boost safety and encourage activity.

• Centralized parking frees space for walking/cycling.

• Bike storage and coworker norms promote bike commuting.

John Snow and the Birth of Epidemiology

• John Snow (father of epidemiology) linked the 1854 London cholera outbreak to a contaminated Broad Street water pump, disproving the prevailing air-spread theory.

• His intervention (removing the pump) halted the outbreak, showing the impact of environment and infrastructure on health.

• Disease transition chart: All-cause mortality decreased significantly with improved water/sanitation.

Policy and Public Health Frames

• Healthy People 2020: A policy reference point for public health goals related to PA.

• SEM places the built environment in the outermost ring, influencing behavior through various levels.

Social Structural Determinants and Socioeconomic Status (SES)

• Structural determinants: Social and political mechanisms creating stratification in social class, determining SES (income, occupation, education, social class).

• Macro system: Characteristics of a culture affecting opportunity structures.

• Geographic life expectancy differences (e.g., Chicago) reflect unequal environments.

• Higher SES generally correlates with longer life expectancy and greater PA; income is a strong predictor.

• Higher income provides more PA options (gyms, safe neighborhoods).

• Policies should reduce income-related gaps to improve PA access.

• Perceived social cohesion and relatedness promote sustained PA.

Gender, Race, and PA: Trends and Considerations

• Fewer females often meet PA guidelines than males.

• Lifestyle and home culture significantly influence youth PA.

• Cultural/religious factors (e.g., dress codes) can create barriers for certain groups.

• Segregation and lack of relatedness correlate with poorer health outcomes.

• Interventions are needed at multiple levels to address these barriers.

Practical Implications and Interventions

• Acknowledge lifespan differences due to social structural determinants and neighborhood environments.

• Interventions can target SEM levels:

  • Individual: self-efficacy for PA.

  • Interpersonal: support networks, coworker norms.

  • Organizational: policies (bike storage, flexible breaks).

  • Community: pedestrian-friendly designs (density, diversity, lighting, benches).

  • Policy: smart growth and reduced sprawl.

• Emphasize equity, especially for lower-income groups.

Quick Reflections and Key Takeaways

• Built environment shapes PA via SEM; density, diversity, design are key.

• Connectivity and land-use mix promote PA; sprawl undermines it.

• John Snow's case highlights environment's health impact.

• Public health policies guide integration of environmental/social determinants.

• SES, income, gender, race interact with environments to influence PA and longevity; addressing disparities needs multi-level strategies.

• Theory combined with practical application improves health outcomes.

Summary of Key Equations and Symbols

• Crow-fly distance for a bird: $D_{ ext{bird}} = v_b t$

• Road-network distance for a car: $D_{ ext{car}} = L_{ ext{road}}(C, X)$

Notes for Exam Preparation

• Define built environment and SEM.

• Explain the three Ds with examples and their PA relevance.

• Describe sprawl vs. smart growth and three walkability features.

• Understand John Snow's case, its significance, and environment-health links.

• Articulate how SES, income, gender, race influence PA/health; real-world implications.

• Explain self-determination theory's intersection with social support and PA.

• Discuss policy and ethical implications of urban design on health equity.