“The key problem is we have this internal biological clock which is set to the external world as a result of exposure of the light/dark cycle.” “From (Thomas) Edison’s production of the first cheap commercial lightbulb, we were able to invade the night at low cost and sleep was the first victim,” says Russell Foster, a sleep expert and Oxford University professor. So how did working all night start anyway? There are few official figures but according to a study by Princeton University, an estimated 7-15% of the workforce in industrialised countries were engaged in some form of night work, despite the World Health Organization having classified night work as a probable cause of cancer due to disruption of circadian rhythms. It’s very daunting.”Īround the world, millions of people work nights. “If your reaction time or observation time is a little slower, it certainly increases our risk while we are working. “Night time is more dangerous on a variety of fronts,” she says. But in her line of work it’s also potentially hazardous.

There’s less people on the road, the variety of calls, the pattern is different, less commercial businesses are open,” says Tracey.

Graveyard shift