IngentaConnect Thoracic Size-selection of Fibres: Dependence of Penetration on F...

Abstract:

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.

Keywords: fibre; size-selective aerosol sampling; sampler penetration; fibre length classification

Document Type: Original article

Affiliations: Health and Safety Laboratory, Health & Safety Executive, Broad Lane, Sheffield S3 7HQ, UK:

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$35.09 plus tax Refund Policy

ArticleThoracic Size-selection of Fibres: Dependence of Penetration on Fibre Length for Five Thoracic Sampler Types

Article
Thoracic Size-selection of Fibres: Dependence of Penetration on Fibre Length for Five Thoracic Sampler Types