Review of Published Laboratory-Based Aerosol Sampler Efficiency, Performance and Comparison Studies (1994-2021).

We provide a narrative review on the published peer-reviewed scientific literature reporting sampler efficiency, performance and comparison studies (where two or more samplers have been assessed) in laboratory settings published between 1994 and 2021 (27 year period). This review is a follow-up to our narrative review on the published peer-reviewed scientific literature reporting sampler comparison in workplace settings. Search terms were developed for Web of Science and PubMed bibliographic databases. The retrieved articles were then screened for relevance, with those studies meeting the inclusion criteria being taken forward to data extraction (25 studies). The most common fraction assessed has been the inhalable fraction, with the IOM sampler being the most studied inhalable sampler and the SKC Aluminium cyclone being the most studied respirable sampler from the identified relevant articles. The most common aerosol used has been aluminium oxide. It was evident that standardisation for these sampler performance experiments is lacking. It was not possible to identify any discernible trends for the performance of samplers when assessed with different aerosols. The need for more detailed and informative data sharing from authors is highlighted. This includes provision of clear identifiable information on the samplers used for testing, sampler flow rates (both manufacturer and those actually used in the study, with an explanation given of any differences), detailed information on the test aerosols used and the sampler substrate materials used. An identified gap in the literature is the potential to perform studies aimed at revaluating the performance of samplers to allow any longer-term temporal changes in performance to be assessed. One approach in advancing the field is to produce an updated protocol for the laboratory testing of samplers. This updated protocol would be beneficial for both the research and occupational hygiene community and would allow harmonised assessment and reporting of sampler comparison studies.