On the contamination of ambient air by preparations carried out with a band-saw

Minimizing aerosol bone dust during autopsies

When sawing bone for medical or medico-legal procedures, fine, airborne dust is produced (aerosols) that can pose a health hazard when inhaled. The aim of this study was to determine the influence of saw blade frequency and contact load, bone condition, test environment, and saw blade type, on the production of aerosol particles. A custom test setup was designed, manufactured and used in 8 bone sawing experiments, using a particle counter to determine the production of aerosol particles while varying the 5 chosen parameters. The number of counted particles was highest with higher saw blade frequencies, lower saw blade contact loads, in dry completely skeletonized bone compared to fresh bone, and using an electrical oscillating saw compared to hand-sawing. Under all conditions, the high amount of aerosol counted posed potential health risks. The ventilation system that we tested was adequate in removing the produced particles, but these high-tech systems are not always available in developing countries or emergency situations. The production of aerosols can be reduced by optimizing the sawing parameters. However, even the lowest number of aerosol particles counted during the current study was high enough to cause potential health risks to practitioners. Safety precautions should be taken, such as external ventilation, proper breathing gear, and adequate protocols, to truly minimize the risk in all bone sawing scenarios.

Aerosol production during autopsies: The risk of sawing in bone

When sawing during autopsies on human remains, fine dust is produced, which consists of particles of sizes that may fall within the human respirable range, and can act as vectors for pathogens. The goal of this study was to explore the potential effects of saw blade frequency and saw blade contact load on the number and size of airborne bone particles produced. The methodology involved the use of an oscillating saw with variable saw blade frequencies and different saw blade contact loads on dry human femora. Released airborne particles were counted per diameter by a particle counter inside a closed and controlled environment. Results corroborated with the hypotheses: higher frequencies or lower contact loads resulted in higher numbers of aerosol particles produced. However, it was found that even in the best-case scenario tested on dry bone, the number of aerosol particles produced was still high enough to provide a potential health risk to the forensic practitioners. Protective breathing gear such as respirators and biosafety protocols are recommended to be put into practice to protect forensic practitioners from acquiring pathologies, or from other biological hazards when performing autopsies.

Aerosol Generation During Bone-Sawing Procedures in Veterinary Autopsies

Bone-sawing procedures are routinely performed during veterinary and human autopsies and represent an important source for infectious aerosols. Here we investigate the generation of aerosols during bone-sawing procedures using 5 different saws regularly used in veterinary and human pathology. In particular, the electrical bone band saw produced vast amounts of aerosolized particles less than 5 µm in diameter, which spread rapidly throughout the entire autopsy hall, leading to an exposure of all personnel. Other sawing devices tested were a diamond-coated cut grinder, an oscillating saw, a reciprocating saw, and a hand bone saw. Although these saws, especially the handsaw, generated fewer aerosolized particles than the band saw, the level of exposure of the saw operator would still be of concern in cases where infectious material would require sawing. Contamination of the entire autopsy area was successfully prevented by the construction of a separately ventilated sawing cabin inside the existing autopsy room. Saw operators in this cabin, however, were exposed to even higher aerosol concentrations. Protection of saw operators was achieved by using a powered air-purifying respirator. In conclusion, our results demonstrate that all bone-sawing procedures applied in veterinary and human pathology can generate aerosols that are of concern for the health of autopsy personnel. To reduce the risk of aerosol infections from bone-sawing procedures, efficient and properly designed ventilation systems to limit the spread of aerosols and appropriate personal protective equipment against aerosols for exposed personnel should be implemented.

Assessment of Air Quality During Mastoidectomy

Objectives. The Occupational Health and Safety Administration (OSHA) outlines specific requirements governing the use of respiratory protection for workers dealing with dust or other aerosolized compounds. Health care workers may be exposed to bone dust produced during otologic procedures, creating an occupational hazard. The purpose of this research was to quantify the total suspended particulate matter (TSPM) and respirable particulate matter (PM5) created during cortical mastoidectomy and investigate whether the concentration of aerosolized dust during mastoidectomy would require the use of a particulate respirator.

Study Design. Cadaveric study to assess air quality during cortical mastoidectomy.

Setting. Temporal bone laboratory.

Methods. A simple mastoidectomy was performed on 3 cadaveric temporal bones. Suspended particulate concentration was measured using gravimetric filter methodology for TSPM and PM5. Concentration of particulate exposure was compared between mannequins positioned near the surgical field with a standard surgical mask, surgical respirator, or controls.

Results. The average total particulate matter concentration during cortical mastoidectomy was 1.89 mg/m3. The average quantity of respirable particles was below detection levels. The calculated particulate exposure concentrations for TSPM and PM5 did not exceed OSHA’s requirement for respirator use. The particulate respirator prevented exposure to bone particulates compared with controls ( P = .028).

Conclusion. The concentration of bone dust produced during cortical mastoidectomy is below regulatory guidelines for use of particulate respirators. However, experimental studies show the use of a surgical respirator may decrease particulate exposure.