That's how it is. A study done in September 2021 by researchers at the Harvard T.H Chan School of Public Health found that high concentrations of particulate matter PM 2.5 and the accumulation of carbon dioxide (CO2) are linked to a reduction in the concentration of employees. Natural ventilation is not enough to clean your work environments. An air purifier will be an excellent aid that will not only lighten the atmosphere in your office but will be of great help in improving and maintaining the performance of your workers.