University of Cincinnati utilizes WIBS and PAX to understand the impact of COVID-19 lockdowns on bioaerosols and equivalent black carbon

Research Goal:

The purpose of this project was to assess the indoor and outdoor bioaerosol- and black carbon-related contaminant levels during and after the COVID-19 related shutdown in Cincinnati, Ohio. The team conducted continuous bioaerosol measurements utilizing the WIBS-5 (Wideband Integrated Bioaerosol Sensor – version 5) and black carbon measurements utilizing a PAX (Photoacoustic Extinctiometer) from a residential apartment in Cincinnati, Ohio, during the months of July to September 2020.

Droplet Science Scope:

Droplet launched a call for proposals in Spring 2020 with the intent of collaborating with researchers to understand the impact of COVID lockdowns on aerosol types that are indicative of anthropogenic activities, and whose composition can be harmful to human health.  Droplet selected the proposal from Yao Addor (PhD student in the Environmental and Industrial Hygiene program) and his advisor Dr. Tiina Reponen of the University of Cincinnati to receive two instruments, WIBS-5 and PAX, in support of this research goal.  Droplet Science worked with the student throughout the data collection period and continues to mentor in the analysis of the collected data.

Project Execution:

Scientists: University of Cincinnati engaged with Dr. Darrel Baumgardner of Droplet’s Science team to assist in operation of the instruments, analysis of the collected data, and continued mentoring of the student in understanding of bioaerosols and black carbon

Instruments:  The project included two cutting edge instruments from Droplet Measurement Technologies, as well as samplers and spore traps from the University of Cincinnati lab. Droplet instruments included the WIBS-5 (Wideband Integrated Bioaerosol Sensor – version 5) to monitor indoor and outdoor bioaerosol concentrations, including levels of airborne bacteria, fungi, pollen, and other unspecified airborne biological agents, and PAX (Photoacoustic Extinctiometer) to monitor indoor and outdoor effective black carbon concentration as a surrogate for traffic-related air pollution

Activity: The team conducted continuous bioaerosol and black carbon measurements in a residential apartment in Cincinnati, Ohio, from July to September 2020. The date of August 31, 2020 was chosen as the cut-off for during and after shutdown since schools reopened at the beginning of September in the school district where the measurements were taken.


Preliminary statistical data analysis indicates that the total and fluorescent particle levels were significantly higher indoors compared to outdoors. The mean particle levels appeared to be higher after the shutdown compared to during the shutdown.

“The collaborative effort between the University of Cincinnati professor and her graduate student and scientists from Droplet Measurement Technologies, using Droplet’s Wideband Integrated Bioaerosol Spectrometer (WIBS) and Photoacoustic Extinctiometer (PAX), was a very illustrative example of how universities and corporations can work together to address pressing environmental problems. In this research, the WIBS and PAX were used to document the impact of the Covid-19 lockdown on the concentration of bioaerosols and equivalent black carbon, aerosol types that are indicative of anthropogenic activities and whose composition can be deleterious to humans. These measurements form the central part of the student’s doctoral research.” said Dr. Darrel Baumgardner, Chief Scientist at Droplet Measurement Technologies.

Talk to an expert

Speak with one of our scientists or experts at Droplet Measurement Technologies today to discover solutions that can power your research.

Let's Talk