New passive air sampler clip may help assess individual exposure to SARS-CoV-2

Masks, social distancing, proper hygiene and ventilation can help reduce the transmission of COVID-19 in public places, but even with these measures, scientists have detected airborne SARS-CoV-2 in indoor settings. Now, researchers reporting at ACS’ environmental science and technology paper developed a passive air sampling clip that may help assess individual exposure to SARS-CoV-2, which may be particularly helpful for workers in high-risk settings, such as restaurants or health care facilities .

COVID-19 is primarily spread through the inhalation of virus-laden aerosols and respiratory droplets that infected individuals exhale when coughing, sneezing, speaking or breathing. Researchers have used active air sampling devices to detect airborne SARS-CoV-2 in indoor settings; However, these monitors are usually large, expensive, non-portable and require power. To better understand individual exposure to the virus, Crystal Pollit and her colleagues wanted to develop a smaller, lighter, cheaper, and wearable device that requires no power source.

The researchers developed a wearable inert air sampler, known as the Fresh Air Clip, that continuously adsorbs virus-filled aerosols onto a polydimethylsiloxane (PDMS) surface. The team tested air samples in a rotating drum in which they generated an aerosol containing a surrogate virus, a bacteriophage that has properties similar to SARS-CoV-2. They detected the virus on a PDMS sampler using polymerase chain reaction (PCR), indicating that the device can be used to reliably estimate airborne virus concentrations.

Then, the researchers distributed clips of fresh air to 62 volunteers who wore the monitors for five days. PCR analysis of the clips detected SARS-CoV-2 RNA in five clips: four were worn by the restaurant’s server and one by a homeless shelter worker. The highest viral load (over 100 RNA copies per clip) was detected in two badges from restaurant servers. Although the Fresh Air Clip has not yet been commercialized, these results indicate that it may serve as a semi-quantitative screening tool to assess individual exposure to SARS-CoV-2, with The same could help identify high-risk areas for indoor exposure, say the researchers.