Work and Fatigue: About the Center

NIOSH has a longstanding interest in how nonstandard work hours, like shift work and long hours of work, impact the health and safety of the U.S. workforce.

Why the Center Was Established

Almost 40 million American wage and salary workers—nearly 30% of the American workforce—are employed in a schedule that is outside of a “regular daytime shift”1. One in four workers — over 30 million people — report working more than 40 hours per week 2. Nonstandard shifts are associated with impaired sleep and numerous negative health outcomes, including an increased risk for cancer, cardiovascular disease, obesity, adverse reproductive health outcomes, gastrointestinal disorders, diabetes, and psychological disorders (like) depression3-6. Disrupted or shortened sleep can impact cognition, increasing the risk for injuries to workers and their coworkers7-10. Worker fatigue can also have a devastating public safety impact, particularly in occupations with high risk consequences. Investigations into two high profile disasters — the nuclear meltdown at Three Mile Island and the grounding of the Exxon Valdez oil tanker — reported that worker fatigue and human error were partly attributable11,12. Aside from these high profile disasters, fatigue-related safety issues can occur every day, as tired workers drive on public roads, raising public health and safety concerns13,14.

Our Purpose

The mission of the NIOSH Center for Work and Fatigue Research is to expand on established work on health and safety risks related to nonstandard schedules to include other sources of fatigue. Examples include physically and mentally demanding work, co-morbidities, hot environments and other co-exposures. The Center works to develop practical, effective solutions to mitigate these risks through collaboration with researchers, policy makers, employers, workers, and health and safety professionals.

2021 CWFR Performance One-Pager


  1. 2015 National Health Interview Survey, Occupational Health Supplement.
  2. 2019 Bureau of Labor Force Statistics, Current Population Survey.
  3. International Agency for Research on Cancer. Night Shift Work: IARC Monographs on the Identification of Carcinogenic Hazards to Humans. 2020.
  4. Rosa RR. Plain language about shiftwork. US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Biomedical and Behavioral Science, Education and Information Division; 1997.
  5. Caruso CC. Negative impacts of shiftwork and long work hours. Rehabil Nurs. 2014;39(1):16-25.
  6. Moreno C, Marqueze E, Sargent C, Wright Jr K, Ferguson S, Tucker P. Working Time Society consensus statements: Evidence-based effects of shift work on physical and mental health. Industrial health. 2019;75(2):139-157.
  7. Dembe AE, Erickson JB, Delbos RG, Banks SM. Nonstandard shift schedules and the risk of job-related injuries. Scand J Work Environ Health. 2006;32(3):232-240.
  8. Wagstaff A, Lie J. Shift and night work and long working hours-a systematic review of safety implications. Scand J Work Environ Health. 2011;37(3):173-185.
  9. Wong IS, Popkin S, Folkard S. Working Time Society consensus statements: A multi-level approach to managing occupational sleep-related fatigue. Industrial health. 2019;57(2):228-244.
  10. Wong IS, McLeod CB, Demers PA. Shift work trends and risk of work injury among Canadian workers. Scandinavian journal of work, environment & health. 2011 Jan 1:54-61.
  11. United States. National Transportation Safety Board. Office of Surface Transportation Safety, United States. National Transportation Safety Board. Marine Accident Report: Grounding of the US Tankship, Exxon Valdez on Bligh Reef, Prince William Sound Near Valdez, Alaska, March 24, 1989. The Board; 1990.
  12. US Nuclear Regulatory Commission. Investigation into the March 28, 1979 Three Mile Island Accident by the Office of Inspection and Enforcement (Investment Report No. 50-320/j79-10). July, 1979. NTIS NUREG-0600.
  13. National Safety Council. Drowsy Driving.
  14. National Highway Transportation Safety Administration.

Center Contact email

Program Leader:

Imelda S. Wong, PhD
Senior Service Fellow (Epidemiology / Occupational Hygiene), Division of Science Integration

Assistant Coordinator:

Zoë Dugdale, MPH
Research Epidemiologist, Spokane Mining Research Division

Program Managers:

Christine Whittaker, PhD
Director, Division of Science Integration

Naomi G. Swanson, PhD
Senior Science Advisor, Division of Science Integration

Rene Pana-Cryan, PhD
Director, Economic Research and Support Office

Casey Chosewood, PhD
Director, Office for Total Worker Health®

Page last reviewed: January 19, 2021, 12:00 PM