A study to explore the physiological impact of AIR+ KN95 masks on children

Masks remain essential for prevention and control of disease, and they may also be the only intervention to provide protection from air pollution including haze. While disposable particulate respirators are commonly used to protect against PM 2.5 and pathogens, most commercially available masks are designed for adults and do not fit children properly. This study evaluated the safety and physiological impact of the AIR+ KN95 mask developed specifically for children aged 7 to 14 years. The study recruited 100 healthy participants and measured the physiological impact of mask use, focusing on end-tidal carbon dioxide (ETCO 2 ), oxygen saturation, heart rate, and respiratory rate. Results showed that ETCO 2 levels were within safe limits (below 50 mmHg) in both resting and mild exertion states, with minimal reported breathing discomfort. Additionally, the mask adequately fit all participants, passing the mask fit test. Although the study was limited in duration, its findings suggest that the AIR+ KN95 mask is safe, comfortable, and effective for routine daily activities in school-going children, without significant respiratory compromise. Further research could explore its long-term use and applicability to children with respiratory conditions. [Trial registration number: NCT07037381]. Clinical trial registration number and date of registration: (DD/MM/YYYY) NCT07037381 21/06/2025. Weblink: https://clinicaltrials.gov/ct2/show/NCT07037381 .