03/11/2011

Wood Dust Sampling: Field Evaluation of Personal Samplers When Large Particles Are Present

Recent recommendations for wood dust sampling include sampling according to the
inhalable convention of International Organization for Standardization (ISO)
7708 (1995) Air quality-particle size fraction definitions for health-related
sampling. However, a specific sampling device is not mandated, and while
several samplers have laboratory performance approaching theoretical for an
'inhalable' sampler, the best choice of sampler for wood dust is not clear. A
side-by-side field study was considered the most practical test of samplers as
laboratory performance tests consider overall performance based on a wider
range of particle sizes than are commonly encountered in the wood products
industry. Seven companies in the wood products industry of the Southeast USA
(MS, KY, AL, and WV) participated in this study. The products included hardwood
flooring, engineered hardwood flooring, door skins, shutter blinds, kitchen
cabinets, plywood, and veneer. The samplers selected were 37-mm closed-face
cassette with ACCU-CAP™, Button, CIP10-I, GSP, and Institute of Occupational
Medicine. Approximately 30 of each possible pairwise combination of samplers
were collected as personal sample sets. Paired samplers of the same type were
used to calculate environmental variance that was then used to determine the
number of pairs of samples necessary to detect any difference at a specified
level of confidence. Total valid sample number was 888 (444 valid pairs). The
mass concentration of wood dust ranged from 0.02 to 195 mg m-3. Geometric mean
(geometric standard deviation) and arithmetic mean (standard deviation) of wood
dust were 0.98 mg m-3 (3.06) and 2.12 mg m-3 (7.74), respectively. One percent
of the samples exceeded 15 mg m-3, 6% exceeded 5 mg m-3, and 48% exceeded 1 mg
m-3. The number of collected pairs is generally appropriate to detect a 35%
difference when outliers (negative mass loadings) are removed. Statistical
evaluation of the nonsimilar sampler pair results produced a finding of no
significant difference between any pairing of sampler type. A practical
consideration for sampling in the USA is that the ACCU-CAP™ is similar to the
sampler currently used by the Occupational Safety and Health Administration for
purposes of demonstrating compliance with its permissible exposure limit for
wood dust, which is the same as for Particles Not Otherwise Regulated, also
known as inert dust or nuisance dust (Method PV2121).


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AplusA-online.de - Source: Annals of Occupational Hygiene