2024 Yes Evaluation of the Little Rock Green Schoolyard initiative: a quasi-experimental study protocol https://doi.org/10.1186/s12889-023-15891-6 Barenie, Matthew J. North America Experimental Exposure Students Elementary (K-5) Green space Particulate Matter (PM) Test performance Stress/Anxiety Other Green space Physical activity accelerometry childhood obesity green schoolyards Child health quasi-experiment environmental strategies Describes a quasi-experimental protocol evaluating green schoolyard upgrades in two Arkansas elementary schools. Outcomes include physical activity, air quality, and academic data. Study focuses on health equity and implementation. 2023