A commercially-available, high-volume (28.3 Lpm) Andersen-type cascade impactor was modified in order to extend its operational range further into the range of large inhalable particles for purposes of use in an exposure assessment study in the primary nickel production industry. The modification involved incorporating a 10-ppi (pores per inch) porous plastic foam top stage that has a wide penetration curve with a 50dae-value of approximately 27 μm. This enabled the upper end of the range of the instrument to be extended from about 10 to greater than 70 μm. The inlet of the original instrument was also modified to incorporate the new top stage and provide 'representative' aspiration of total airborne particulate with an efficiency of close to 100% over the range of aerodynamic particle sizes of interest. A mathematical inversion algorithm developed in earlier research was modified so that it could be applied to this new instrument. This enabled raw data on particulate material recovered from all stages of the instrument (including the new porous foam top stage) to be used for the determination of continuous particle size distributions, as well as chemical speciation, over the inhalable range. The new instrument was deployed in a pilot field study in the nickel primary production industry by which to demonstrate the potential of the new instrument for generating useful information pertaining to health-relevant aerosol size tractions (e.g., inhalable, thoracic, and respirable), and for soluble, sulphidic, metallic, oxidic and total nickel chemical species groups.
|Original language||English (US)|
|Number of pages||14|
|Journal||Annals of Occupational Hygiene|
|State||Published - 2001|
Bibliographical noteFunding Information:
The authors wish to thank International Nickel Company (Inco) Ltd and Falconbridge Ltd for their generous financial support of this work Particular appreciation is owed to the professional occupational hygiene staff of both companies, especially Mr. Tom Mehes, CIH, (Inco) and Heather Walker, CIH (Falconbridge); also to the staff of the J. Roy Gordon Research Laboratory, notably Mr. Nelson Zelding, for their contributions both to the field sampling and analytical components of this study. Finally, we are grateful to Dr. Avula Sreenath for his assistance in setting up the laboratory experiments.
- Cascade impactor
- Inhalable aerosol
- Particle size distribution
- Porous foam media