2007-12-05 08:15:09
By Clare Davidson
Business reporter, BBC News
How does it feel to be working while most people are sleeping? Following a
series on night work, we look at the side effects of working unusual hours.
At only 27, Abigail Medniuk is resigned to decades of working odd hours.
"I knew my career would be open to a lifetime of night shifts and anti-social
hours," says Dr Medniuk, a senior house officer in anaesthetics at Kent and
Sussex Hospital.
Night workers are always fighting the natural light which the body finds hard
to adjust to
James Waterhouse, Liverpool John Moores University
Since qualifying in 2004, her hours have varied considerably, she says as she
rushes between patients. At one extreme she has worked continuously on nights
over seven days.
In her new job she avoids the long stretches of nights, but jumps between night
shifts and day shifts at two or three day intervals.
She accepts the hours, but is emphatic on one point: "You never get used to
it."
Body clock
What becomes immediately obvious from talking to researchers is how disruptive
night work is for the body. This has huge health implications.
The most obvious result of night work or shift work outside normal office hours
is the disruption to the circadian rhythm, or body clock.
The body clock helps us stay awake and alert in the daytime and enables us to
sleep and recuperate at night, explains James Waterhouse, a sport and exercise
science specialist at Liverpool John Moores University.
Our body temperature rises during the day and boosts naturally occurring levels
of adrenaline. In the evenings, the body cools down, reaching its lowest
temperature in the early hours.
"Night workers are always fighting the natural light, which the body finds hard
to adjust to," he says.
Doing damage
It is not simply a matter of inadequate sleep. Even when workers do sleep it is
often poor quality and interrupted.
"Workers can take the phone off the hook and have the thickest curtains
possible, but surrounding daytime noises continue regardless," says Jim Horne,
director of Loughborough University's Sleep Research Centre.
Fatigue and accumulative sleep deprivation can be insidious, developing slowly
over time with workers unaware of its impact, according to the Health & Safety
Executive (HSE).
But it can also be potentially disastrous, if judgement is impaired or
concentration compromised, especially for operators of machinery. According to
the HSE, the incident of accidents on night shifts are higher.
Night-time workers' fatigue has been cited as a factor in several well-known
disasters, according to a report by the Association of Professional Sleep
Societies. These include the Exxon Valdez oil spill, the Bhopal chemical blast
and the Chernobyl nuclear explosion.
Cutting the risks associated with night and shift work would help improve
workers' health and safety. But the HSE is keen to stress that it could also
help businesses financially by reducing absenteeism, injuries and accidents,
while also boosting productivity.
24 hour society?
Accidents aside, researchers say disrupting the circadian rhythm and the
resulting lack of sleep can have a range of other effects.
Research has shown gastrointestinal disorders are common complaints by night
workers, says Debra Skene, head of the Neuroendocrinology School of Biomedical
and Molecular Sciences at Surrey University. These include indigestion, loss of
appetite and peptic ulcers.
In a sense 24-hour society is here but it isn't here truly
James Waterhouse, Liverpool John Moores University
And increased risks of cardiovascular problems, such as hypertension, are
another issue. What causes this is not exactly clear, says Mr Waterhouse.
But antisocial hours means not only are workers awake when their bodies want to
be asleep, they tend to have less access to facilities that help maintain a
healthy lifestyle. For example night workers are less likely to join a gym or
association that might have physical and social benefits, he says.
"In a sense the 24-hour society is here, but it isn't here truly."
Access to decent healthy food at night is a common problem. He says often night
workers eat their evening meal with their families or partners because it is
the main time to catch up. But this can create problems regarding what to do
during the main break at work.
"People don't feel like a full meal so resort to eating crisps or chocolate,"
he adds.
'No solution'
There are better and worse aspects of the different types of rotas used for
night work, says Ms Medniuk.
It is a relief that in her new job she doesn't face the prospect of seven
consecutive nights at work. On the other hand, her current rota is completely
irregular and she says the time off is not enough to do much.
Night work
Night workers are those who regularly work for at least three hours between
11:00pm and 6:00am
Employers must offer a free health assessment before starting work at night and
regularly after that
Fatigue, sleep deficit and a disrupted circadian rhythm are said to be
exacerbated by 12 hour shifts
Advancing shifts (mornings, then afternoons, then nights) are easier to adapt
to than the reverse
Source: London Hazards Centre, Health & Safety Executive
These two models - one with the week of nights compared to two and three days
stints - are commonly used by employers that operate shift or night work.
A more extreme option involves around a month of nights or late shifts followed
by time off.
But fundamentally, the problem with all these patterns is the clash between
trying to work at night, when everyone else including family and friends are
not, while having a "normal" life in between researchers say.
"There is no solution because we tend to revert to being daytime creatures,"
says Mr Waterhouse.
He adds the best way to truly adapt to night work would be to stick to being
awake at night even on days off. A weekend lie-in is not the solution, he says.
Above all, the body wants regularity.
This applies not only to night shifts but also for people working other
irregular shifts, says Ms Skene. Getting up at 4am or 5am is likely to mean
people are always short of sleep because they are unlikely to have gone to bed
the extra two to three hours earlier.
Moreover, constantly changing patterns is disastrous for the body as the
circadian rhythm is "completely shot", says Mr Skene. It might take several
weeks to rectify an irregular pattern over several years.
"What long term damage is done to other parts of the body - we have no idea,"
she adds.
Haphazard
A spokesperson for the Transport and General Workers Union says there is plenty
of information available but all too often organisations don't seek advice when
devising shifts.
Mr Horne echoes this, saying firms organise night shifts as if they were simply
day shifts.
Working at night is "fundamentally different" and many decisions about shift
patterns "seem haphazard" he says. This includes the increasing trend of
12-hour night shifts "even though there isn't the research to show it is a good
idea".
Organisations can gain advice to avoid the worst case scenarios he adds.
"Employers don't understand that working at night might be a health issue as
well as a safety issue," says T&G.
Mr Waterhouse sums up the problem by saying society has fundamentally changed
in a very short period, but human biology has not.
Some cope better than others, but whatever expectation we have of a 24-hour
society, we cannot eliminate our inbuilt body clock.