Objectives The mining industry is increasingly adopting extended workdays of 10–12 hour shifts. Studies demonstrate that long work hours are associated with psychomotor impairments caused by fatigue and an increased risk of injury. However, studies involving miners remain limited. This analysis aimed to identify risk factors associated with long working hour injuries and to determine if long working hour incidents were associated with being killed or incidents involving multiple injured workers.
Methods Data from US Mine Safety and Health Administration Part 50 reports, 1983–2015, were used to identify long working hour injuries, which were defined as incidents occurring nine or more hours after the start of a shift.
Results A total of 52 206 injuries (9.6%) occurred during long working hours. The proportion of long working hour injuries increased from 5.5% of all injuries in 1983 to its peak in 2015 at 13.9% (p<0.001). Risk factors associated with long working hour injuries included irregular shift starts, being newly employed, employment by a contractor, metal/non-metal operations and mines with <100 employees. In two separate adjusted models, long working hour injuries were associated with a higher odds of death (adjusted OR [aOR]=1.32; 95% CI 1.18 to 1.48) and single incidents resulting in two or more workers injured (aOR=1.73; 95% CI 1.58 to 1.89).
Conclusions Long working hour injuries were associated with a lack of routine, being new at the mine and specific mining activities. An international shift towards using contract labour and extended workdays indicates that injuries during long working hours will likely continue to grow as a problem in the mining industry.
- occupational injury
- overtime work
- extended work shifts
- long working hours
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
Contributors The undersigned author warrants that the article is original, is not under consideration by another journal and has not been published previously. The authors have read and approve this manuscript for publication. All authors meet the criteria for authorship stated in the Uniform Requirements for Manuscripts Submitted to Biomedical Journals. LSF had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. LSF was involved in the conception and design, acquisition of data, analysis and interpretation of the data, drafting of the article and statistical expertise. KSA was involved in the acquisition of data, conception and design, analysis and interpretation of the data and review of the written manuscript. RAC was involved in the conception and design, analysis and interpretation of the data and review of the written manuscript.
Funding This research was supported in part by funding from The Alpha Foundation for the Improvement of Mining Safety and Health, Inc. This project was also partially funded through the NIOSH surveillance program. Additional funding was provided in part by the Centers for Disease Control and Prevention through a U60OH010905 grant.
Disclaimer The views, opinions and recommendations addressed herein are solely those of the authors and do not imply any endorsement by the Alpha Foundation, its directors and staff. And, the views expressed in manuscript do not necessarily reflect the official policies of the Centers for Disease Control and Prevention or the Department of Health and Human Services.
Competing interests None declared.
Ethics approval The University of Illinois at Chicago IRB approved this work (# 2013–0714).
Provenance and peer review Not commissioned; externally peer reviewed.
Patient consent for publication Not required.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.