ects on women
The effects of shift work (particularly night work) on
pregnancy and menstruation are being increasingly
documented.
A study of the effects of night work on nearly 800 women
found that the incidence of irregular menstrual cycle was
significantly higher in women working nights than in
women working during the day. The results indicate that
night work may suppress ovarian function by affecting
hormone levels which are governed by the circadian
rhythms.
While evidence of adverse effects of shift work on
pregnancy is mixed, extended working hours can worsen
the effects of other hazards during pregnancy. These
include standing for long periods; working in heat and cold;
lifting or other physically demanding tasks; and exposure
to chemical, biological and radiation hazards – all of which
may affect the health and safety of the pregnant women,
G:TrainingAwards Acts & PoliciesShift Work Guidelines.DOC Page 6
the development of the foetus, and may also have health
implications for breast feeding.
Older employees
Coping with shift work and extended working hours
may become more difficult for older employees, due to
interaction between:
• changes in circadian rhythms
• reduced ability to cope with stressors
• increased sleep fragility – sleeping less, waking
earlier
• cumulative effects of years of shift work.
Young workers
Young workers, particularly those under 18 years,
need longer and more frequent rest breaks and should
not work night or extended shifts.
Cumulative effects
The hazards associated with shift work and extended
working hours increase with the level of exposure.
Even with well-designed rosters, long periods of shift
work and extended hours will increase the health and
safety risk. When shift work and extended hours are
worked in excess of the length and timing
recommended in these Guidelines, the risk will be
substantially increased. The more the
recommendations are exceeded, and the longer the
period over which this occurs, the greater the risk.
8. OVERCOMING THE HAZARDS OF SHIFT WORK
AND EXTENDED WORKING HOURS
STEP 1: A SAFE PROCEDURE
Consultation
Changing shift rosters can fundamentally affect
working, social and domestic lives of employees. A
process of ongoing consultation between employees
and management is essential to minimise or control
any harmful effects.
All new shift work rosters should be developed,
monitored, evaluated and agreed by a joint working
party. This must include representatives from all
employees who will be affected, OHS and trade union
representatives. Senior or middle management
should also participate, so final decisions can be made
within the working party