Study Examines Occupational Exposure to Bioaerosols during Embalming
A new study published by IRSST, a nonprofit scientific research organization in Québec, Canada, examined embalmers’ exposure to bioaerosols to evaluate potential health risks to these workers. The researchers describe the objective of embalming a body as “to maintain hygiene by slowing down the process of putrefaction.” Embalmers are responsible for tasks such as chemically treating bodies as well as providing aesthetic care ahead of a viewing, for example. (The embalming process is described in detail in the Synergist article “Mortal Exposures,” which discusses industrial hygiene in the death care industry.) The IRSST study also sought to analyze the effects of certain factors on the behavior of biological particles in air. According to the authors, few studies have addressed exposure to bioaerosols in embalming, and the death care industry lacks specific recommendations for applying general ventilation to control bioaerosols during the process.
Researchers assessed three embalming laboratories, performing bioaerosol sampling in the air and on surfaces in the facilities. They also applied computational fluid dynamics to assess how factors such as the number of air changes per hour, the laboratories’ dimensions, and ventilation strategies affected the behavior of bioaerosols, their concentration, and dispersion. The research team found that certain tasks—such as those resulting in splashing or an ejection of air by means of compression—were likely to generate increased concentrations of bioaerosols near embalmers but that on average, the workers were exposed to low levels of bioaerosols.
The team identified strains of bacteria belonging to the non-tuberculous Mycobacterium family in two of the laboratories. These bacteria belong to Risk Group 2, which Canadian regulations describe as representing moderate risk to the health of individuals and low risk to public health. Researchers were also able to culture another human pathogen from Risk Group 2, Streptococcus pneumoniae, in several samples from two of the laboratories they studied.
“The culturing of Streptococcus pneumoniae proves that bacteria from the human respiratory tract can be found in culturable state in the air of embalming labs,” the authors explain. “Most bioaerosols have diameters of less than 4 µm (so-called respirable fraction), which means that they have a strong possibility of being deposited in the respiratory tract and a strong potential to circulate in the air of embalming rooms.”
It is difficult to know whether pathogens exist in dead bodies and near embalmers, according to the researchers. For example, the authors note that embalmers may be exposed to respiratory tract viruses from deceased persons who were not tested or diagnosed prior to their passing. Additional concerns identified during the IRSST study include embalmers’ proximity to the bodies, the variety of work tasks for which embalmers are responsible, and the uncertainty regarding the dilution of contaminants using general ventilation, which the researchers say is often the only method used to control bioaerosols in embalming laboratories. Based on these findings, the research team recommends that workers involved with embalming wear, at minimum, air-purifying respiratory protective equipment such as an N95-rated filtering facepiece respirator.
A summary of the study, “Assessing Embalmer Exposure to Bioaerosols and the Associated Health Risk,” can be found on IRSST’s website. The study is available for download in English and French.
Related: A previous IRSST study examined workers’ exposure to microorganisms when using biological degreasing stations. And earlier this year at AIHce EXP, bioaerosol scientist Quinn Aithinne presented on the challenges of bioaerosol sampling.