TY - JOUR
T1 - Thoracic size-selection of fibres
T2 - Dependence of penetration on fibre length for five thoracic sampler types
AU - Maynard, Andrew D.
N1 - Funding Information:
Acknowledgements—This work was made possible through the loan of equipment and support from Paul Baron and Gregory Deye at the National Institute for Occupational Safety and Health, Cincinnati, Ohio. The research was supported by the UK Health & Safety Executive.
PY - 2002/8
Y1 - 2002/8
N2 - It has been suggested that the non-size-selective sampling methods currently used for fibrous aerosols potentially lead to the presence of large compact particles, agglomerates and fibre clumps in samples, which in turn reduce the accuracy and precision of the manual fibre counting techniques employed to analyse samples. The use of thoracic size-selective samplers has been proposed as an alternative, leading to the prevention of large particles reaching the collection substrate while at the same time bringing fibre sampling into line with general occupational aerosol sampling methodologies. Thoracic samplers should give good agreement with current sampling methods under ideal conditions based on aerodynamic fibre properties. However, the effect of fibre length on sampling efficiency is not known. The sampling efficiency of five thoracic samplers was therefore measured as a function of fibre length for respirable fibres between 10 and 60 μm long. These included the commercially available GK2.69 cyclone and the CATHIA sampler, the IOM thoracic sampler, a modified version of the SIMPEDS cyclone and a modified version of the IOM inhalable sampler. Length-monodisperse fibres were generated using a dielectrophoretic fibre classifier and sampler penetration was measured as a function of fibre length. No length-dependent sampling effects were observed for the CATHIA, GK2.69, modified SIMPEDS and modified IOM inhalable samplers for fibres <60 μm. Data for the IOM thoracic sampler showed a significant trend of reducing sampling efficiency for fibres >30 μm. Overall, the laboratory results indicated that the five sampler types are likely to perform as well as or better than the currently used 25 mm cowled sampler in the field.
AB - It has been suggested that the non-size-selective sampling methods currently used for fibrous aerosols potentially lead to the presence of large compact particles, agglomerates and fibre clumps in samples, which in turn reduce the accuracy and precision of the manual fibre counting techniques employed to analyse samples. The use of thoracic size-selective samplers has been proposed as an alternative, leading to the prevention of large particles reaching the collection substrate while at the same time bringing fibre sampling into line with general occupational aerosol sampling methodologies. Thoracic samplers should give good agreement with current sampling methods under ideal conditions based on aerodynamic fibre properties. However, the effect of fibre length on sampling efficiency is not known. The sampling efficiency of five thoracic samplers was therefore measured as a function of fibre length for respirable fibres between 10 and 60 μm long. These included the commercially available GK2.69 cyclone and the CATHIA sampler, the IOM thoracic sampler, a modified version of the SIMPEDS cyclone and a modified version of the IOM inhalable sampler. Length-monodisperse fibres were generated using a dielectrophoretic fibre classifier and sampler penetration was measured as a function of fibre length. No length-dependent sampling effects were observed for the CATHIA, GK2.69, modified SIMPEDS and modified IOM inhalable samplers for fibres <60 μm. Data for the IOM thoracic sampler showed a significant trend of reducing sampling efficiency for fibres >30 μm. Overall, the laboratory results indicated that the five sampler types are likely to perform as well as or better than the currently used 25 mm cowled sampler in the field.
KW - Fibre
KW - Fibre length classification
KW - Sampler penetration
KW - Size-selective aerosol sampling
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U2 - 10.1093/annhyg/mef063
DO - 10.1093/annhyg/mef063
M3 - Article
C2 - 12176765
AN - SCOPUS:0036675059
VL - 46
SP - 511
EP - 522
JO - Annals of Work Exposures and Health
JF - Annals of Work Exposures and Health
SN - 2398-7308
IS - 6
ER -