Several handling procedures embalmers perform on the bodies of deceased persons produce bioaerosols that contain potentially pathogenic microorganisms. In a recent study, strains of Streptococcus pneumoniae were cultivated in samples taken in embalming laboratories, showing that bacteria from the human respiratory tract could be found in cultivable condition in the air of these labs. No search for viruses was done.
This study, which was conducted in three embalming labs, showed that, on average, workers engaged in embalming activities are exposed to low levels of bioaerosols; nevertheless, several tasks carried out by embalmers are likely to trigger peak aerosol emissions of up to 45 times the baseline level. The actions that can result in the greatest increases in concentration are the following:
- incision suturing
- orifice plugging
- washing and drying of the body
- equipment preparation and cleaning
- use of a trocar (a key task in determining embalmers’ exposure to bioaerosols)
Moreover, although this study concerned only embalming activities, it is possible that other funeral care services that involve handling cadavers may also generate bioaerosols.
The aerodynamic diameter (size) of the particles measured indicates that bioaerosols emitted during embalming activities usually fall into the respirable fraction (< 4 µm, emission measured during use of a trocar). These particles can penetrate deep into the respiratory tract and be deposited there. In addition, since small particles remain airborne for long distances and over long periods, an embalmer may be exposed to bioaerosols produced by other workers (unless he/she works alone in the lab), or be exposed even a long time after the embalming job.
Similarly, a modelling examination of ventilation strategies showed that particle deposition is a less significant elimination mechanism than ventilation, with maximum fractions of deposited particles lower than 3%. Digital simulations have highlighted the importance of general ventilation as a means of controlling bioaerosols in embalming labs. Nevertheless, ventilation systems installed in laboratories may have variable efficiency, resulting in uncertainty regarding the actual reduction in bioaerosol concentration.
Various authors have documented the fact that numerous pathogens have been identified in organic fluids from cadavers for which the cause of death was certified as not being an infectious disease . Other studies point out that a substantial percentage of cadavers are identified as infectious only during the autopsy or embalming. Finally, since it is impossible to guarantee the absence of infectious contaminants on and in human remains , embalmers’ exposure, by inhalation, to such contaminants belonging to Risk Group 2 or 3 cannot be ignored.
- The decision on whether to wear respiratory protection equipment during embalming must not based on the identification of a risk of infection according to the death certificate, particularly since the purpose of this document is in no way related to protecting workers’ health and safety.
- From a risk management perspective, during all post-mortem work, any bodily fluid or tissue or aerosol resulting therefrom must be considered to be potentially infectious. Preventive practices against exposure to infectious and chemical agents must be applied at all times, for all cadavers, regardless of the established or presumed cause of death, the time elapsed since death or any other information contained in the death certificate.
- Embalmers must be aware of the presence of infectious aerosols, their source and their dispersal; their working methods must be adapted to reduce exposure at all times.
- Although currently no regulatory level of exposure to microorganisms has been established, the tool developed jointly by researchers from the IRSST and Université de Montréal, called A support tool for choosing respiratory protection against bioaerosols, can be used to determine what kind of respiratory protection equipment is appropriate for funeral care.
Considering the difficulty of identifying the presence of pathogens in human remains, the embalmer’s proximity, the wide variety of tasks involved and the uncertainty associated with the dilution of contaminants by general ventilation, the authors of the study recommend blocking the cadaver’s airway while handling the body or, at the very least, considering wearing air-purifying respiratory protection equipment with a half mask (N/R/P-95/99/100). Embalming is not permitted in the case of persons who have died of certain diseases, including COVID-19.