BOULDER, Colo. — We're in the middle of Colorado kids returning to school, which means more time spent inside. We don't get to choose the air we breathe, but improving the air in classrooms is a goal for researchers at CU Boulder, and they're making progress.

"We started with elementary school classrooms and the idea was to improve ventilation in the highest density public schools," Dr. Mark Hernandez, professor of Civil and Environmental Engineering , said. In 2021, Dr.

Hernandez said they started their research in Denver Public Schools . They installed air quality monitoring sensors inside DPS classrooms to see what kids were breathing in real time. He said they found that HEPA air filters dramatically improved poor air quality in classrooms, for less than the cost of a textbook per child, per year.

Credit: 9NEWS - Amy Hunter A portable HEPA air filter used to conduct research at the CU Boulder Aerobiology Lab. RELATED: Study finds poor air quality in school dramatically improves with filters This research was born out of the pandemic, but has expanded beyond just the concerns of infectious diseases. Dr.

Hernandez said thousands of portable air filters have been deployed in classrooms across the state because of this research, thanks to a partnership with the Colorado Department of Public Health and Environment (CDPHE) and grant funding from the CDC (Center for Disease Control). "We now have data from ventilation performance for buildings all over the state. The good news.