School sustainability: The implications of implementing living walls at schools for air purification

The average public school in the United States contains thousands of students, teachers, and staff. In a small, enclosed space with little ventilation, this can cause the circulation of unwanted pathogens, hazardous gases, and more. Previous studies have shown the benefits of plants in improving air quality under controlled laboratory conditions; however, these benefits have yet to be tested in real-world settings. In this study, we assessed the efficacy of integrating living walls in a school environment to enhance indoor air quality. We hypothesized that the presence of plants from the living wall would reduce the concentrations of air pollutants in the surrounding area. To test this hypothesis, we measured the concentrations of common air pollutants over a few months, utilizing the living wall at Brooklyn Technical High School and an air quality monitor. We analyzed the collected data using the Analysis of Variance (ANOVA) hypothesis test to determine whether air quality was improving. Our results showed that there was no statistically significant difference in particulate matter (PM2.5, PM10) concentrations with and without the living wall; however, formaldehyde (HCHO) and total volatile organic compound (TVOC) concentrations revealed statistical significance in both cases. Additionally, we observed lower standard deviations and maximums of air pollutant concentrations in the presence of plants, suggesting that living walls may play a role in regulating air pollutant fluctuations. Our study showed that the living wall can play an integral part in increasing the predictability and consistency of indoor air pollutants.