UE News, February, 1998
More than 15 million U.S. workers perform shift work of some sort; that
is, they work regularly outside of normal daylight hours. Some simply work evenings
occasionally. But four percent of U.S. workers are permanent night workers, or have
irregular work schedules. Still another four percent have the most stressful of work
routines of all rotating shift work.
Many different types of jobs require shift work. Those who take care of
hospital patients, the mentally ill or prisoners must perform their services 24 hours a
day. Toll collectors, municipal snow emergency workers, and many other public employees,
not to speak of police officers and fire fighters, must work or be on call at all hours.
In manufacturing plants and service shops, workers often have to work the evening shift.
Many drivers of transportation and delivery vehicles have to work evening or late night
All of these work shifts take a toll on human health, according to a
recently published NIOSH report ("Plain Language About Shift Work," July 1997).
They all result in greater fatigue for shift workers.
LONG TERM EFFECTS
"We might think that permanent night workers adapt or get used to
their work times," according to the authors Drs. Roger Rosa and Michael Colligan.
"However, research tells us that most permanent night workers never really get used
to the schedule. Fatigue occurs because most night workers go back to a day schedule on
their days off." (My emphasis-D.K.) This is not surprising because family and
friends are active during the day. Also many errands and chores, like getting the car
fixed, must be done during the day. Because most night workers return to a day schedule
they never completely allow their sleep and body rhythms to adapt to being awake at
Also, the report notes, night workers sleep less during the day, and sleep
less deeply when they do sleep. Thus fatigue can build up over time, resulting eventually
in accidents, such as dozing off when operating machinery or driving a vehicle.
But worse than losing sleep is losing contact with others, especially
family members, according to surveys of shift workers.
In the long term, shift work appears to cause digestive problems, such as
frequently upset stomachs, persistent constipation and sometimes stomach ulcers.
Scientists believe this happens because shift work puts a persons activity schedule
out of "sync" with their natural body rhythms (their so-called
"circadian" rhythms). These natural rhythms slow down regular body functions at
night, when shift workers are working, and speed them up during the day, when they are
trying to sleep. This is a good prescription for poor sleep and persistent digestive
REDUCING SHIFT-WORK HEALTH PROBLEMS
Below are some suggestions for reducing shift-work health problems made by
the NIOSH report. But as the report says, these should be considered as "suggestions,
not as strict guidelines or regulations." They may be useful in a particular job
situation, but "all aspects of job and home life must be considered" when
changing a work schedule:
Avoid quick shift changes. A break of only seven to 10 hours
should be avoided before rotating to a new shift, such as going from day to night shift on
the same day of the week. A short break means the person may be tired when beginning the
next shift, and accidents can result. At least 24 hours of break time are recommended
after ending a night-work shift.
Try to keep work schedules regular and predictable. It is
important to know these well in advance to plan rest, child care and family and other
Re-examine the schedule of rest breaks. Standard lunch and coffee
breaks may not be appropriate for your particular job. For example, in Las Vegas, card
dealers, who need to concentrate intensely, get 10 to 15 minutes break per hour.
For physically demanding jobs, a short break every hour might help fight muscle fatigue.
When considering such changes, of course, discuss them first at the local meeting or with
the shop health and safety committee, since they can affect everyone.
Revised work schedules which involve 10 to 12 hour work shifts, followed
by several days off, are being considered or tried out in some U.S. plants these days. The
NIOSH report makes clear that such long shifts, even when followed by long breaks,
"can be very fatiguing." While some workers prefer the
"mini-vacations" that result, older workers especially may find it difficult to
fully recover before starting work again. The result: a long-term build up of fatigue.
(Note: If you would like a copy of this report free of charge, or have
questions about it, call the NIOSH hot line at 1-800-35NIOSH [1-800-356-4674]. Again,
its called "Plain Language About Shift Work," NIOSH Publication Number