Health Effects of Shift Work

Approximately one-quarter of Canadian workers are shift workers. Excluding occupations requiring 24-hour staffing (e.g., emergency services), shift work is a way for employers to maximize the use of machinery and other physical capital.

The Institute for Work and Health recently released a summary of its symposium on the health effects of shift work. A high-level briefing is available here. Among the more alarming impacts of shift work on workers are:

1. Shift work appears to elevate the risk of breast cancer and possibly colorectal cancer. There are some studies suggesting that shift work may also elevate the risk of preterm delivery, gastrointestinal disorders and mental health problems.

2. The level of workplace injury is higher among shift workers than among those who work regular shifts. This is particularly the case for shift workers working at night. Among the issues contributing to this is that government regulation (e.g., inspections) of workplaces tends to occur during week days.

It appears possible to mitigate these effects through scheduling changes that constrain shift-work during non-regular hours.

This discussion suggests that the organization of work is not solely a technical undertaking focused on optimizing production schedules. Rather the organization of work can have a significant effect on the health and safety of workers.

-- Bob Barnetson