Implementation Outcomes and Impacts of Ciudad Medio Ambiente y Salud: An Environmental Initiative Promoting One Health in Iquitos, Peru

Abstract

Colonialism, extractivism, and rapid urbanization in Iquitos—the largest city in the Peruvian Amazon—have disrupted core urban systems, limiting access to green space, health services, and environmental infrastructure, and contributing to interconnected human, ecological, and environmental crises. With only 1 m² of green space per capita, Iquitos is one of the most green-deficient cities in Peru. Addressing this deficit may mitigate multiple dimensions of One Health.Ciudad Medio Ambiente y Salud (Ciudad MAS) is a residential garden program designed to promote the adoption of residential green spaces to address mental health, vector-related risks, and environmental quality. This dissertation first specifies Ciudad MAS using implementation science frameworks, including Proctor’s recommendations for reporting implementation strategies and the Implementation Research Logic Model. It then evaluates findings from a pilot cluster randomized trial assessing implementation outcomes, environmental quality, and mental health. The specification process demonstrates that participatory environmental design initiatives can be systematically adapted for scale through implementation science. Strategies derived from prior design experience aligned with Expert Recommendations for Implementing Change (ERIC). The pilot achieved high adoption of functional gardens. Although green space per capita did not increase, residential environmental quality improved through increased tree planting, maintenance, and accessibility. Acceptability, appropriateness, and feasibility were high at baseline and remained high, suggesting strong implementation readiness. No significant short-term effects were observed on anxiety or depression scores. However, residential satisfaction improved, and exploratory analyses suggest a plausible pathway linking built-environment improvements to mental health outcomes. Overall, this work demonstrates that residential gardens can function as scalable, implementation science–informed One Health interventions in land-constrained and resource-limited cities.