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Wood dust sampling: field evaluation of personal samplers when large particles are present.

Lee T, Harper M, Slaven JE, Lee K, Rando RJ, Maples EH - Ann Occup Hyg (2010)

Bottom Line: 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).Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type.

View Article: PubMed Central - PubMed

Affiliation: Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA. fwc8@cdc.gov

ABSTRACT
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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Box plot of wood dust mass concentration ratios between the pairs of the samplers without outliers. The horizontal lines in the box plot from bottom to top indicate 10th, 25th, 50th (median), 75th, and 90th percentiles. The circles indicate the 5th (lower circle) and 95th (upper circle) percentiles. A is ACCU-CAP™, B is Button sampler, C is CIP10-I, G is GSP sampler, and I is IOM sampler (total number of pairs is 444).
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fig4: Box plot of wood dust mass concentration ratios between the pairs of the samplers without outliers. The horizontal lines in the box plot from bottom to top indicate 10th, 25th, 50th (median), 75th, and 90th percentiles. The circles indicate the 5th (lower circle) and 95th (upper circle) percentiles. A is ACCU-CAP™, B is Button sampler, C is CIP10-I, G is GSP sampler, and I is IOM sampler (total number of pairs is 444).

Mentions: The box plot for wood dust mass concentration ratios between 15 different pairs of the samplers for all sampling sites is shown in Fig. 4. The median mass concentration ratio for all pairs ranged from 0.62 (ACCU-CAP™ and CIP10-I pair) to 1.07 (CIP10-I and GSP pair). Table 2 shows correlation coefficient, average difference in mass concentration (from random effects model), and correction factors for each pair of samplers. All the pairs showed a strong and statistically significant (P < 0.05) correlation between samplers, except for pairs ACCU-CAP™/ACCU-CAP™, Button/CIP10-I, and Button/GSP. Average difference between the groups calculated from GM for each pair ranged from 0.03 (Button/Button pair and GSP/IOM) to 6.66 (ACCU-CAP™/ACCU-CAP™) mg m−3 and all P-values are >0.05, implying that the mass concentrations of wood dust from side-by-side sampling are not significantly different. The average difference between ACCU-CAP™ and ACCU-CAP™ is very large due to single large mass concentration (195 mg m−3). When this value is considered as outlier, the average difference between the samplers drops to just 0.01 mg m−3 and the correlation between pairs becomes significant with a coefficient of 0.83 (P < 0.001). The number of collected pairs is generally appropriate to detect a 35% difference with 80% power at an alpha level of 0.05. A difference of 35% may be considered more appropriate for field studies, as opposed to the NIOSH 25% criterion for laboratory studies, as field studies can have highly variable environmental conditions (Bartley et al., 2007). Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type. Correction factors ranged from 0.16 (pair of ACCU-CAP™ and ACCU-CAP™ samplers) to 1.13 (pair of CIP10-I and CIP10-I samplers). Correction factor as defined here means that the average level of wood dust measured by the ACCU-CAP™ was the same as that of Button (for ACCU-CAP™ and Button samplers pair) when the stated correction factor (0.91) was applied to the concentration measured by the Button. The average differences between the identical sampler pairs (in Table 2) may reflect the ability of the sampler to collect more or less coarse particles. Variability increases for samplers, such as the IOM, expected to collect coarser particles.


Wood dust sampling: field evaluation of personal samplers when large particles are present.

Lee T, Harper M, Slaven JE, Lee K, Rando RJ, Maples EH - Ann Occup Hyg (2010)

Box plot of wood dust mass concentration ratios between the pairs of the samplers without outliers. The horizontal lines in the box plot from bottom to top indicate 10th, 25th, 50th (median), 75th, and 90th percentiles. The circles indicate the 5th (lower circle) and 95th (upper circle) percentiles. A is ACCU-CAP™, B is Button sampler, C is CIP10-I, G is GSP sampler, and I is IOM sampler (total number of pairs is 444).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC3037778&req=5

fig4: Box plot of wood dust mass concentration ratios between the pairs of the samplers without outliers. The horizontal lines in the box plot from bottom to top indicate 10th, 25th, 50th (median), 75th, and 90th percentiles. The circles indicate the 5th (lower circle) and 95th (upper circle) percentiles. A is ACCU-CAP™, B is Button sampler, C is CIP10-I, G is GSP sampler, and I is IOM sampler (total number of pairs is 444).
Mentions: The box plot for wood dust mass concentration ratios between 15 different pairs of the samplers for all sampling sites is shown in Fig. 4. The median mass concentration ratio for all pairs ranged from 0.62 (ACCU-CAP™ and CIP10-I pair) to 1.07 (CIP10-I and GSP pair). Table 2 shows correlation coefficient, average difference in mass concentration (from random effects model), and correction factors for each pair of samplers. All the pairs showed a strong and statistically significant (P < 0.05) correlation between samplers, except for pairs ACCU-CAP™/ACCU-CAP™, Button/CIP10-I, and Button/GSP. Average difference between the groups calculated from GM for each pair ranged from 0.03 (Button/Button pair and GSP/IOM) to 6.66 (ACCU-CAP™/ACCU-CAP™) mg m−3 and all P-values are >0.05, implying that the mass concentrations of wood dust from side-by-side sampling are not significantly different. The average difference between ACCU-CAP™ and ACCU-CAP™ is very large due to single large mass concentration (195 mg m−3). When this value is considered as outlier, the average difference between the samplers drops to just 0.01 mg m−3 and the correlation between pairs becomes significant with a coefficient of 0.83 (P < 0.001). The number of collected pairs is generally appropriate to detect a 35% difference with 80% power at an alpha level of 0.05. A difference of 35% may be considered more appropriate for field studies, as opposed to the NIOSH 25% criterion for laboratory studies, as field studies can have highly variable environmental conditions (Bartley et al., 2007). Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type. Correction factors ranged from 0.16 (pair of ACCU-CAP™ and ACCU-CAP™ samplers) to 1.13 (pair of CIP10-I and CIP10-I samplers). Correction factor as defined here means that the average level of wood dust measured by the ACCU-CAP™ was the same as that of Button (for ACCU-CAP™ and Button samplers pair) when the stated correction factor (0.91) was applied to the concentration measured by the Button. The average differences between the identical sampler pairs (in Table 2) may reflect the ability of the sampler to collect more or less coarse particles. Variability increases for samplers, such as the IOM, expected to collect coarser particles.

Bottom Line: 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).Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type.

View Article: PubMed Central - PubMed

Affiliation: Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA. fwc8@cdc.gov

ABSTRACT
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).

Show MeSH
Related in: MedlinePlus