Health impact of shift working

The health impact of shift working is not well understood. We need more research and better risk assessment to protect workers.


The numbers of staff working shifts is increasing and there has been a marked increase in those working night shifts. While traditionally more men than women have worked shifts, that is changing with most of the new shift workers being women. Scotland has always had a higher proportion of shift workers than the rest of the UK and a range of UNISON’s public service workers are involved including the emergency services, hospitals, social care and in the energy sector.


I was in Stirling today, outlining the health implications to our police branch stewards and discussing how we can help members by designing work better to address these issues.


The research on this issue has identified a number of risk factors associated with shift workers. They are more likely to be obese, suffer from diabetes, smoke (particularly women) and eat less healthily. Interestingly, they are also more likely not to drink alcohol. While there is a statistical correlation between shift workers and these conditions, it is less clear what the causal link is. Shift workers are also more likely to be in lower income groups, who generally have poorer health.


Likely explanations focus on the disruption to circadian rhythms, the body’s internal clock. This can disrupt the workings of the hormone Melatonin, which can lead to poor sleep. We know that the lack of good quality sleep has been linked to obesity, depression, diabetes and heart disease.


A particularly worrying study showed that women working on night shifts for more than 30 years are twice at risk of breast cancer. This is thought to be linked to less Melatonin, which has cancer protective qualities and increased Oestrogen that has the opposite effect.


Another issue is a 40% increase in the risk of cardiovascular disorders. The causal reasons are unclear, but again the disruption to the circadian rhythm, damage to family and social life, stress and poor diet are obvious contributing factors.

So what can be done to limit the risks?


One health site gives the unhelpful advice of ‘get another job’! Although impractical and drastic, it may well be good advice for the over 40’s and those who have worked on shifts for many years. Some behavioural solutions help, such as establishing a stable sleep environment and schedule. Eating small health snacks on shift rather than a large meal, together with exercise and limiting stimulants like caffeine and energy drinks.


We should also be revisiting risk assessments with employers. This involves evaluating shift schedule design - avoiding split shifts, excessive 12 hour shifts and rotating shifts forward. There should be at least 48 hours between shift changes to allow the body to adjust. Occupational health should identify and treat workers who have sleep disorders and ensure more regular health checks from age 40 and those who have worked shifts for more than ten years.


Finally, we need more research to understand the causal links between shift work and ill health. In the meantime there needs to be better awareness of the risks and the actions workers and employers can take to minimise the risks.