2024 No Observed mask wearing and presence of SARS-CoV-2 in school wastewater, San Diego County, CA, 2022 https://doi.org/10.2105/AJPH.2024.307925 Fielding-Miller, Rebecca North America Observational Experimental Students Staff Elementary (K-5) Middle/Jr High (6-8) High School (9-12) Viruses COVID-19 Mask wearing Wastewater COVID-19 SARS-CoV-2 Schools This observational study linked masking behaviors to SARS-CoV-2 in wastewater at 10 San Diego elementary schools. A 10% rise in masking corresponded to a 10% drop in viral detection, supporting masking as a school mitigation tool. 2025