Long working hours drive up the risk of injury and illness regardless of the job you do, according to a new study. Research published this week in the journal Occupational and Environmental Medicine shows the greatly increased risk has nothing to do with how hazardous the job is. US researchers analysed the responses of almost 11,000 Americans to the annual National Longitudinal Survey of Youth. After adjusting for age, gender, type of industry and job, employees working overtime were 61 per cent more likely to sustain a work related injury or illness than employees who did not work overtime. Working at least 12 hours a day was associated with a 37 per cent increased risk of injury or illness, while working at least 60 hours a week was associated with a 23 per cent increased risk, compared with those who worked fewer hours.

Report co-author Allard Dembe commented: 'The results of this study suggest that jobs with long working hours are not more risky merely because they are concentrated in inherently hazardous industries or occupations. Our findings are consistent with the hypothesis that long working hours indirectly precipitate workplace accidents through a causal process, for instance, by inducing fatigue or stress in affected workers.' The more hours worked, the greater was the risk.

The authors say their findings support government initiatives, such as those espoused by the European Union, to cut working hours. TUC policy adviser Paul Sellers said the findings were unsurprising. 'It is clear that working long hours is not good for you. And what is important is to realise that it is not fair on other people. If you are involved in an accident whether at work or because you are tired from work it can involve other people.' He added: 'Often it is the case of a workplace not being organised properly that people work long hours.'

Source: A. Dembe and others. 2005. The impact of overtime and long work hours on occupational injuries and illnesses: new evidence from the United States, Occupational and Environmental Medicine, 62: 588-97 (not available online).