Study: Ventilation Key to Limiting Virus Risks to Plant Workers

Workers wear protective masks and stand between plastic dividers at Tyson Foods’ poultry processing plant in Camilla, Ga., in April. (Tyson Foods via AP)

(CN) — Working shoulder-to-shoulder in one large room, shouting at each other over loud machinery, meatpacking workers are at severe risk of contracting Covid-19. New research found ventilation is key to preventing major outbreaks at these plants.

Meatpackers account for 0.16 % of the U.S. population, but they make up 1% of all Covid-19 cases in the U.S., roughly 166,000, said Felicia Wu, a Michigan State University toxicology professor who presented a study Tuesday in which she and her colleagues developed a Covid-infection risk model for the meatpacking industry.

“That’s staggeringly high,” she said.

Along with prisons and nursing homes, some of the largest Covid-19 outbreaks in the U.S. have occurred at meatpacking plants. The biggest was this spring at Smithfield Foods’ pork plant in Sioux Falls, South Dakota, in which 1,294 workers and hundreds of their close contacts came down with the virus and four workers died.

Though the company shut down the plant at the urging of elected officials, it was only for two weeks as President Trump issued an executive order in late April deeming meatpacking plants essential businesses that should stay open to provide a continued supply of protein for Americans. Through open-records requests, the news organization ProPublica found Trump cribbed the order from a draft written by the North American Meat Institute, a trade group that represents companies that process 95% of beef, pork and veal and 70% of turkey products in the U.S.

Smithfield’s plant, which can process up to 20,000 hogs per day, is one of 12 large-scale meatpacking plants forced to temporarily shutter this year due to coronavirus outbreaks with disastrous results for the industry, Wu said, speaking at the Society for Risk Analysis’ annual conference.

“Because farmers cannot easily take their animals and go to another meatpacking plant because they may be spread far apart, or overloaded with animals, they’ve actually had to euthanize a large number of livestock,” Wu said in a virtual symposium.

Margaret Beestra, an Ohio State University graduate student, discussed her interviews of 28 Ohio farmers for her study on how the pandemic affected them at the conference and cited a CBS News headline from May stating, “Farmers Will Have to Euthanize Millions of Pigs as Meat Plants Remain Closed.”

She said as a workaround to the plant closures, some of the farmers she talked to got creative: A few had customers come to their farms and sold them hogs or cows, while one built a small butchering facility on site.

She said butcher shops in the Midwest are now booked years in advance by farmers who panicked when Covid-19 outbreaks forced meatpacking plants to temporarily close.

The prices of meat in grocery stores has fluctuated wildly throughout the year due to the plant closures. In August, the price of 15-pound briskets at an HEB grocery store in Houston went from $45 to $75 the next week then back to $45.

Wu said some meatpacking plants tried to take precautions to protect their workers early in the pandemic, only to learn the measures were not very effective as research on the virus evolved.

In April, Tyson Foods put thin plastic coverings between assembly line workers at one of its meatpacking plants, Wu said.

“That was when we believed Covid-19 was primarily transmitted through droplets so they might fall fairly easily to the ground … Now, however, we know a primary route of transmission is aerosol transmission so…these plastic sheets actually do not protect workers from Covid-19 infection,” Wu said.

She and her team created a model to estimate the viral load of coronavirus in meatpacking plants based on the half-life of the virus, the rate at which humans breathe, how much virus is expelled when an infected person breathes, talks or coughs and the air-exchange rates.

“What we found in our model, the air-exchange rate is crucial to reducing the viral load to minimize infection risk,” Wu said, adding that air exchange is also crucial for the buses that are commonly used to transport meatpacking plant workers, many of whom are immigrants, to and from work.

Asked if ventilation can be easily adjusted in U.S. meatpacking buildings, Wu said if the building is up to code it should be relatively easy to improve ventilation rates.

“It’s much more of a problem in individual houses…For example if you have people coming into your house, even if you opened up all the windows, the most you could achieve is maybe three complete air exchanges in an hour,” Wu said.

But well-ventilated buildings can achieve six complete air exchanges per hour or more, Wu noted.

“So that certainly is a possibility, but it completely depends on retrofitting and what infrastructure for ventilation is already there,” she said, adding that she hopes to publish her research quickly to put companies and plant managers on notice of her findings.

Despite the bad press meatpacking companies have received for their numerous Covid outbreaks, Wu said there has not really been much substantive changes in working conditions because the nature of the work cannot accommodate social distancing.

“So what can we promote? she said. “Enforcing effective mask wearing and other protective gear, improved ventilation and air-exchange rates in both the meatpacking and transportation buses, [and] enforcement of sick leave for symptomatic and diagnosed cases.”

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