A recent publication by UNMC researchers assesses the transmission risk of respiratory diseases – such as COVID-19, influenza, and common colds – in meat processing facilities, using air sampling to identify markers of respiratory transmission in both production areas and common areas where workers are in close proximity.
The results, published in December, showed some surprises and offered a blueprint for how to handle future epidemics in a processing environment, according to co-principal investigators Joshua Santarpia, PhD, and Athena Ramos, PhD. In Dr. Santarpia’s words, the results demonstrate “a method for in situ measurements of human-generated particles that can be used more broadly to understand exposure and risk in various occupied spaces.”
Measurements of human-generated aerosols, which were taken at three different plants, exploring all parts of the facility, including the harvesting area, the processing area and common areas such as bathrooms, locker rooms, cafeterias and offices.
“We believe this is the first time that measurements have been taken in a facility during regular occupied production hours,” Dr. Ramos said.
The results showed that poorly ventilated common areas, not production areas, may pose the most risk of exposure to human-generated aerosols, including those that contain viruses. On average, three of four samples that tested positive for respiratory transmission markers were found in common areas at the facilities.
“In the plants themselves, particularly in places like the packing floors, the level of ventilation for food safety was actually doing a good job of helping with prevention,” Dr. Santarpia said. “Whereas some of the areas that we perhaps didn’t initially consider as much, such as the cafeterias and the locker rooms, were where we saw a lot more potential for virus transmission.”
The team tracked a specific messenger RNA from a human respiratory protein, which brings versatility to the methodology, Dr. Santarpia explained.
“By being able to do this in an occupied space, under normal operations, without impacting anything that’s going on, we can get a more real-world picture of what transmission risks look like, what exposures look like,” he said. “It doesn’t have to be when there’s a disease circulating. We can go into any place, at any time, and get an understanding of where the hot spots are for transmission risk.”
The study concluded that two controls should be prioritized to minimize the likelihood of exposure to potentially infectious aerosols:
- Improving mechanical ventilation, such as through normal system maintenance or system re-balancing, and/or adding mitigation strategies such as improved air filtration, germicidal ultraviolet and other air cleaning technology.
- Applying administrative practices that minimize large congregations of people in poorly ventilated spaces such as phased shift changes and staggered lunches and breaks.
Both investigators applauded the collaboration with the meat processing facilities in the study. As part of the collaboration, the team produced site reports for each one of the facilities.
“These are large facilities that employ a lot of people,” Dr. Ramos said. “In addition to the sheer number of workers, we need to account for the types of production activities, the organization of the work and the design of the facility.”
But the very complexity of this study, she said, allows future researchers to apply the methodology into studies of other types of facilities, such as nursing homes and schools.
“The study offers inexpensive interventions that make sense without a major impact to production activities,” Dr. Santarpia said. “There are a lot of positives to be taken from this study.”