Atlantic staff writer Katherine J. Wu wanted to find out if she could fix the air quality in her New England apartment. That led her to discover carbon dioxide-monitoring devices with varying degrees of success. Wu turned to climate and air quality experts for some advice, and learned that other pollutants besides CO2, such as carbon monoxide, nitrogen oxide, and ozone, can be even more harmful to health and environments. There's also the matter of, well, particulate matter, and whether the devices pick those up on their monitors. One of the experts Wu consulted is Nga Lee (Sally) Ng, Love Family Professor in the School of Earth and Atmospheric Sciences, the School of Chemical and Biomolecular Engineering, and the School of Civil and Environmental Engineering.