The reduction of disease transmission, like Covid-19, spurred the increased use of germicidal ultraviolet (UV) light to decrease airborne pathogens. While conventional UV sources pose eye and skin risks, safer alternatives emitting at 222 nanometers have risen in popularity. However, a recent MIT study in Environmental Science and Technology warns of potential indoor air pollutants resulting from the utilization of these UV lights.

Emphasizing the need for strength adjustments and improved ventilation in UV light-fitted indoor spaces, the study indicated that germicidal UV light can react with oxygen to produce ozone, a health risk in itself. Further oxidation reactions could lead to harmful volatile organic compounds (VOCs) and secondary organic aerosols (SOAs).

MIT Professor Jesse Kroll's team, traditionally focused on outdoor air pollution, shifted their attention to indoor air quality as a result of the Covid-19 pandemic. The team found out that the use of UV lights indoors could precipitate reactions akin to those happening in outdoor environments when exposed to sunlight. According to Kroll, the goal is to reach a balance where UV lights deactivate airborne pathogens without generating excessive pollutants.

While the current findings are derived from laboratory experiments, the researchers are confident that their conclusions can shed light on potential chemical reactions in actual indoor environments exposed to UV light devices. Victoria Barber, an ex-MIT postdoc and researcher on the study, asserted that the research provides a fairly clear understanding of the potential chemistry under UV radiation. Her colleague, doctoral student Matthew Goss, noted their work inspired the creation of a model aimed at gaining insight into real indoor environments.

Given the growing popularity of germicidal UV light devices, their safe and efficient usage is crucial. The MIT study primarily emphasizes the need for adequate ventilation and maintaining UV devices.