Linsey Chen Marr is an American scientist who is the Charles P. Lunsford Professor of Civil and Environmental Engineering at Virginia Tech.

[7] Marr joined the faculty at Virginia Tech in 2003, where she established her own research group that investigates how engineered nanomaterials interact with the atmosphere.

[8] Marr showed that when released into the air, engineered nanomaterials can aggregate with other matter to form structures of various sizes (in the nm and μm length scales).

The sensors include a custom-DNA that has been designed to immobilise specific viruses, which are subsequently bound to another DNA strand which can be attached to a gold nanoparticle for viral detection using Raman spectroscopy.

[22][23] In early April 2020 Marr told Chemical & Engineering News that she believed that face masks should be worn to prevent the spread of the virus.

[11][24] Marr predicted that the viral transmission may decrease slightly during the summer, but that the difference would not be particularly significant as people spend more time in air conditioned rooms.

[26] In January 2020, Marr reviewed a research paper by Yuguo Li which found that the long-established 5-micron boundary was fallacious and that most flu, colds, and other respiratory illnesses spread through aerosols, and not droplets.

A Historical Perspective on the Transmission of Respiratory Infectious Diseases", published on 28 April 2021 as a preprint[27] and in October 2021 in the Royal Society's Interface Focus theme issue on COVID-19.

On April 30, the WHO changed its online advice on the transmission of COVID-19, accepting that it can spread by aerosols as well as larger droplets, and Zeynep Tufekci reported in The New York Times that a big news story had passed almost unnoticed.

The Centers for Disease Control and Prevention also made changes to CDC guidance, placing the inhalation of aerosols at the top of its list of how COVID-19 spreads.