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Research Roundup: Aerosols 2 (AIHce EXP 2022 OnDemand)

Course Description:
Recorded at AIHce EXP 2022


Respirable Dust Generated from Cutting Concrete in Laboratory Full-Scale Cutting Tests with Conical Picks at Different Stages of Wear

Respirable dusts (particles small enough to penetrate into human lungs), pose serious long-term health issues to workers using mechanized mining and tunneling machines for hard rock excavation. The purpose of this preliminary study is to characterize and compare the respirable concrete dust particles generated at the pick tip during excavation for different stages of conical pick life. Characteristics of dust particles (e.g., concentration, size distribution, shape) will provide a basis for changing out picks to mitigate dust generation at the source or increase dust controls to limit exposures. This research provides the findings of these specific dust characteristics generated from full scale laboratory cutting tests with a linear cutting machine. A concrete block was used in the experiments with conical picks at new, moderately worn, and fully worn levels of wear. Results strongly suggest an increase in dust levels with wearing of picks, a shift in larger particle sizes with wearing of picks, and some statistically significant differences in particle shapes when cutting with different pick wears.

J. Brune, Colorado School of Mines, Golden, CO, USA
C. Tsai, UCLA, Los Angeles, CA, USA
J. Rostami, Colorado School of Mines, Golden, CO, USA

Acknowledgments & References
M.V. Thyagarajan, Colorado School of Mines, Golden, CO, USA
Syd Slouka, Earth Mechanics Institute Golden, CO
United States of America

Influence of Face Shields on Exposures to Respirable Aerosol
Three face shield designs were tested on a breathing mannequin in a low speed wind tunnel to determine their efficiency at reducing particle exposures for the wearer. While each face shield was shown to reduce the concentration of respirable aerosol in the breathing zone, efficiency varied by particle size and face shield design.

M. Woodfield, University of Utah, Salt Lake City, UT, USA
R. Jones, University of Utah, Salt Lake City, UT, USA

Acknowledgments & References
This research was supported by the University of Utah Office of the Vice President for Research in partnership with the Immunology, Inflammation and Infectious Disease (3i) Initiative.

Dr. Darrah Sleeth, Ph.D., MPH, CIH, University of Utah Salt Lake City, UT
United States of America

Contact Hours:

Presentation Date:

Amanda Kramer, MS, CIH
Syd Slouka
Darrah Sleeth, PhD, MPH, CIH