Room To Breathe: Slaughterhouses And Respiratory Disorders

Public discussion and animal advocacy around slaughterhouses usually focuses on the animals being killed, with good reason. However, it is important to remember that the grueling conditions of the slaughterhouse are also incredibly damaging to the physical and psychological health of the human slaughterhouse workers. For example, the environment of slaughterhouses exposes workers to air that is contaminated by “bioaerosols”, such as bacteria and fungi. Bioaerosols are released at various stages in the slaughter process, such as when cleaning the colons of dead animals. Breathing in bioaerosols is linked to decreased lung function and respiratory problems. This study, published in Safety and Health at Work, focuses specifically on the respiratory health of slaughterhouse workers. 

The study was conducted on 81 industrial slaughterhouse workers as well as 81 healthy office workers, with the intention of comparing lung function between groups. None of the participants had a personal or familial history of respiratory diseases or any known exposure to contaminants. Theoretically, however, slaughterhouse workers would have been exposed to much higher concentration of bioaerosols due to the nature of their work environments. This was confirmed through measurements of bioaerosol concentration, which were obtained using a method from the National Institute for Occupational Health and Safety. The researchers measured lung function of the workers before and after their shifts on three different occasions, then used only each worker’s best result in their data. They also had each worker fill out a questionnaire (from the American Thoracic Society) that assessed for respiratory symptoms. 

The researchers found that the incidence of respiratory symptoms was significantly higher among slaughterhouse workers compared to the reference group. Specifically, the incidence of coughing was 3.17 times higher; productive coughing (coughs that produce phlegm) was 4.02 times higher; breathlessness was 4.66 times higher; phlegm was 3.07 times higher; and wheezing was 3.94 times higher. The researchers noted that the rates of respiratory symptoms found among slaughterhouse workers appear similar to those reported for workers in industries that deal with wastewater, solid-waste, and compost. Unsurprisingly, statistical analysis revealed a significant association between exposure to bioaerosols and poorer lung function, even after adjusting for factors such as age, weight, height, smoking, and length of exposure.

The average slaughterhouse worker had slightly better lung function right before their first shift of the week compared to right after the shift, presumably due to the temporary break from breathing in the bioaerosols from the slaughterhouse. However, they still scored significantly worse on their lung function tests compared to the reference group, showing that the damage to their lung function persists even after having a break from the bioaerosol-filled environment. 

The researchers point out that several specific bacterial and fungal species identified in the slaughterhouses of this study are known pathogens of the respiratory system. Therefore, there is reason to believe that bioaerosols in slaughterhouses could explain the higher incidence of respiratory symptoms and weaker lung function in the slaughterhouse workers compared to the office workers. The researchers suggested that further studies that span longer periods of time and have larger sample sizes will be necessary before establishing a causal relationship. 

Animal advocates can share these findings in animal rights spaces to serve as a reminder that slaughterhouse workers are not the enemy. In fact, they too are harmed by the efficiency-focused killing operations that take place at slaughterhouses. Additionally, advocates can use this information to provide a more well-rounded perspective when discussing the problems with animal agriculture, in that the perspective could encompass genuine concern for their fellow humans as well.