Funding for this research was provided by:
Alpha Foundation for the Improvement of Mine Safety and Health (AFC719-15)
Article History
Received: 25 May 2020
Accepted: 15 September 2020
First Online: 23 September 2020
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: The views, opinions, and recommendations expressed herein are solely those of the authors and do not imply any endorsement by the Alpha Foundation, its Directors, and staff.The findings and conclusions in this report are those of the author(s) and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention. Mention of any company or product does not constitute an endorsement by NIOSH.