A Simple and Disposable Sampler for Inhalable Aerosol

Abstract

The state-of-the-art for personal sampling for inhalable aerosol hazards is constrained by issues of sampler cost and complexity; these issues have limited the adoption and use of some samplers by practicing hygienists. Thus, despite the known health effects of inhalable aerosol hazards, personal exposures are routinely assessed for only a small fraction of the at-risk workforce. To address the limitations of current technologies for inhalable aerosol sampling, a disposable inhalable aerosol sampler was developed and evaluated in the laboratory. The new sampler is designed to be less expensive and simpler to use than existing technologies. The sampler incorporates a lightweight internal capsule fused to the sampling filter. This capsule-filter assembly allows for the inclusion of particles deposited on the internal walls and inlet, thus minimizing the need to wash or wipe the interior sampling cassette when conducting gravimetric analyses. Sampling efficiency and wall losses were tested in a low-velocity wind tunnel with particles ranging from 9.5 to 89.5 μm. The results were compared to the proposed low-velocity inhalability criterion as well as published data on the IOM sampler. Filter weight stability and time-to-equilibrium were evaluated as these factors affect the practicality of a design. Preliminary testing of the new sampler showed good agreement with both the IOM and the proposed low-velocity inhalability curve. The capsule and filter assemblies reached equilibrium within 25h of manufacturing when conditioned at elevated temperatures. After reaching equilibrium, the capsule-filter assemblies were stable within 0.01mg.

Assessment of increased sampling pump flow rates in a disposable, inhalable aerosol sampler

“…These samplers have all been used to assess the worker’s personal exposure to particles in a workplace environment. [10,11]…”

“…[20] However, both the Button and IOM samplers can be costly, retailing for $249.00 and $85.00–$269.00, respectively, which may be cost prohibitive for some health and safety professionals. [10] The CFC costs around $1.00, which makes it a significantly more affordable option. However, the CFC under-samples particles larger than 30 μm in aerodynamic diameter [13] and therefore should not be assumed to estimate inhalable aerosol exposures, particularly when the particle size distribution is known to be large (e.g., wood dust).…”

“…The complexity of the IOM and Button samplers may also play a factor in why they have not been more widely adopted by health and safety professionals, e.g., the IOM has seven components and can be challenging to assemble and maintain. [10] It should also be noted that the Button has difficulty sampling droplet aerosol. [23] Due to their expense, the IOM samplers are not disposable and must be shipped back to the user after laboratory analysis.…”

“…A new, low-cost, disposable inhalable aerosol sampler (Figure 1) was designed by L’Orange et al [10] to assess workers personal exposure to inhalable particles in a workplace environment. The newly designed disposable inhalable aerosol sampler was constructed to be a less expensive option, as well as more user-friendly than other commonly used samplers.…”

“…The capsule allows for the collection of particles deposited on the internal walls of the sampler, similar to the internal cassette of the IOM. [10] Due to the low cost and simple nature of the capsule, after one use it can be discarded, similar to the CFC.…”