There have been suspicions for a long time that meat processing plants are just plain unhealthy due to poor hygiene as well as likely aerosolizing animal viruses which are then inhaled by meat processing workers. This suggests that these places are unable to protect workers from air borne viruses
Results: An excess of deaths from cancers of the base of the tongue, esophagus, lung, skin, bone and bladder, lymphoid leukemia, and benign tumors of the thyroid and other endocrine glands, and possibly Hodgkin's disease, was observed in abattoir and meat processing workers. Significantly lower SMRs were recorded for cancer of the thymus, mediastinum, pleura, etc., breast cancer, and non-Hodgkin's lymphoma.
Conclusion: This study confirms the excess occurrence of cancer in workers in abattoirs and meat processing plants, butchers, and meatcutters, previously reported in this cohort and other similar cohorts worldwide. Large nested case-control studies are now needed to examine which specific occupational and non-occupational exposures are responsible for the excess. There is now sufficient evidence for steps to be taken to protect workers from carcinogenic exposures at the workplace. There are also serious implications for the general population which may also be exposed to some of these viruses.
With respect to SARS-CoV-2 the work environment in meat processing plants is also allowing this virus to be easily transmitted between workers.
Roughly half a million people work in the nation's meat processing industry, and crowded and unsanitary conditions have prompted concerns about worker safety during the coronavirus pandemic. As of April 27, 4,913 meat and poultry plant workers in 115 plants in 19 states had been diagnosed with COVID-19, the disease caused by the coronavirus, and 20 people had died, according to the report from the Centers for Disease Control and Prevention. In 17 states that provided data on how many workers were employed at affected facilities, 3% of more than 130,000 workers were diagnosed with COVID-19, researchers found.
with apparent differences between plants
The share of workers who were infected with COVID-19 ranged from about 1% at affected plants in states like Kansas, Missouri and North Carolina – where 106, 36 and 166 workers were ill, respectively – to about 18% in Iowa, where 377 people tested positive and data on deaths was unavailable.
The virus is fastidious and needs to be grown in special cell cultures. To grow in the wild it really needs a living host and it's hard to imagine that it would readily grow on animal carcasses.
Cancer Mortality in Workers Employed in Cattle, Pigs, and Sheep Slaughtering and Processing Plants