Abstract for Poster 32

Measuring dust particles deposited on skin using a vacuuming sampler

L. Lundgren*¹, L. Skare², C. Lidén^2,3
¹Department of Applied Environmental Sciences (ITM), SU, Stockholm, Sweden
²Department of Medicine, Occup and Environ Dermatology, KI, Stockholm, Sweden
³Stockholm County Council and KI, Stockholm, Sweden

Objective

Airborne skin exposure to allergens and irritants may cause dermatitis. There is a lack of methods for assessing skin exposure to airborne particles. We have modified and tested a filter sampler, for sampling particles deposited on skin by vacuuming. Tests were performed on healthy subjects in a whole-body exposure chamber with continuous generation of airborne cornstarch (see poster “A whole-body exposure chamber for studies of skin exposure to particles“). We sought to use simple, practical and inexpensive equipment available in most occupational hygiene laboratories.

Method

Vacuuming sampler: The sampler for removing deposited particles from the skin by vacuuming was constructed by us. It consists of a three-piece 25 mm black filter cassette with a specially designed metallic nozzle (opening of 10 mm in length and about 1 mm in width). Sampling is performed by connecting the filter device to a stationary pump at a flow rate of 10 LPM. All parts of the sampler (headpiece with nozzle, tube and filter) are included when the amount of dust is evaluated.

Exposure: The airborne dust concentration of cornstarch (used as a model substance in this test) in the whole-body exposure chamber was targeted to about 8 mg/m³ (inhalable dust). The exposure time was 30 min and, in all, 8 subjects were exposed. Areas on both forearms were studied.

Comparison with tape stripping: Results obtained by sampling with the vacuuming sampler were compared with results from a tape stripping procedure on areas close to the areas sampled with the vacuuming device. Tape stripping with Scotch magic tape was used to remove and collect deposited particles on skin. The tape was placed with the sticky surface on the skin and a slight pressure was applied with a roller, which was moved 10 times over the tape before removal.

Analysis: Analysis, for assessment of the amount of cornstarch particles collected by the vacuuming sampler and on the tape, was performed with optical microscopy.

Results

The surface variation (C.V.) on forearms was determined by sampling on up to 4 (with the vacuuming technique) and up to 7 (with tape stripping) contiguous areas. The variation was 2.6-8.0% (95% CI) at dust loadings of 7.0-8.9 µg/cm² for the vacuuming device and 4.2-8.2% at dust loadings of 7.4-8.4 µg/cm² for tape stripping. On comparison between the two techniques, no statistical difference was found; the 95-% CI for the ratio between the two techniques was 0.95-1.08 with an average value of 1.01.

Conclusion

Reproducible results were obtained with the vacuuming sampler and the results were in good agreement with the results obtained with tape stripping. The vacuuming technique may be used for assessment of skin exposure to particles and for dose-effect studies in the same way as tape stripping can. The vacuuming method has the advantage of allowing for dust sampling from fairly large areas of skin.

References

Lidén C, Lundgren L, Skare L et al. A new whole-body exposure chamber for human skin and lung challenge experiments--the generation of wheat flour aerosols. Ann Occup Hyg 42: 541-7, 1998.

Lundgren L, Lidén C, Skare L et al. 2003. Stripping, vacuuming and surrogate skin - measurement of dust on skin. Exog Dermatol 2: 90, 2003.

Lundgren L, Skare L and Lidén C. Measuring dust on skin by using a small vacuuming sampler--comparison with other sampling techniques. To be submitted. 2005.

Content last modified: 17 May 2005