Night Shift,

Shift work’s disruptive impact on our circadian rhythms — the biological clocks in our cells — has been linked to increased infection and cancer risk and higher risk of heart disease and diabetes. It can also put pressure on relationships and lead to social isolation.

Although he can only work a 35-hour week under French law, Robert’s shift pattern, which includes working every other weekend, is antisocial. “I basically lost all my friends. I can’t even see them on weekends, as I work one in two, the other one being spent with my girlfriend. Sure, there are vacations, and sometimes I could make an exception and visit [friends] but, over time, I kept seeing them less and less.”

Robert already had depression and he reckons working nights has made it much worse. He also dislikes his job — it’s tedious, lonely and doesn’t pay well. Even with weekends and a 10% night premium he nets just €1,350 a month. But with no savings, endless bills and a diploma that is no longer valid, he can’t see a way out.

Shift workers feel the cognitive effect of lacking sleep immediately. Sue Prynn, 56, worked night shifts at a factory near Liverpool for a decade. “I worked on manufacturing and distribution, making doughnuts would you believe,” she says, in a light West Country lilt. After 12 hours of packing baked goods amid clouds of flour, the din of machinery and spitting deep-fat fryers, fatigue would make her feel drunk.

Prynn chose to work nights because she was a sole parent who needed to take care of her four children during the day. In a 2004 US labor force survey, 626,000 of the 3.8 million people who worked between 9:00 p.m. and 8:00 a.m. said they did so because it fitted in better with their childcare or family needs. A further 204,000 said it allowed them to attend school or college.

The downside is that many shift workers barely get to bed. Prynn was one of many night workers with young children and no spare cash for nursery. During holidays, or when her children were below school age, she would regularly end her shift, go straight into childcare and then return to work in the evening — adding up to more than 48 hours without rest. “There was always something kicking off,” sighs Prynn. “It can be a bit difficult to control your family . . . If you asked my kids, I’m sure they’d say, ‘Mum [ just] used to cook fish fingers.’ ”

There was no time for slacking on the factory floor either: “If you [and your team] were behind plan, you’d have to come in on Friday night or Saturday morning.” Prynn would pop caffeine supplements called Pro Plus to keep her eyes open. She now works normal hours for the Union of Shop, Distributive and Allied Workers (Usdaw), but one of her daughters went on to work nights baking cookies and another became a live-in care worker, a role that also entails broken sleep.

Some types of night work are relatively new products of our post-industrial economy, such as jobs fulfilling orders at Amazon warehouses or working on the checkout at a 24-hour supermarket. Other professions, however, have long entailed a degree of shift working. Medicine is one of them. “My sleep is broken,” says Angelu Amancio, a psychiatric nurse in San Diego, California, who has worked nights since 2010. “I sleep for three or four hours, wake up, do lunch, have a nap before work.”

Amancio and his wife married in 2012, and “when it was just me and her it was fine . . . when you throw kids into the picture, that’s when it gets more difficult,” he says. “When we had our first kid I was still working nights and we were trying to save up money — we had just bought a house so we didn’t do the whole day-care thing. So there were times when I would have to watch my son during the day. When he would nap, I would nap . . . I was dead tired . . . there were days where I’d be up for 20-plus hours.”

On the eve of 2017, he was diagnosed with Hodgkin lymphoma (he does not link his illness to his shift pattern). After a year of treatment, Amancio is healthy again, back playing sport and working night shifts: his three children now attend day care so he can rest. “I feel like I don’t get to see my family enough. We have three kids now, and it’s become really stressful for my wife. She’s asked me to go for days. It’s something I’ve considered, but as far as what our bills are — day care, house payments, car payments… that night-shift differential, if I were to go to days it would make stuff that much more difficult.” Moving to days would mean $800-$1,000 less a month, he explains.

While the human body may have evolved to sleep in the dark, the modern economy does not stop when the sun goes down. We want to buy fresh doughnuts in the morning; we expect train lines to be mended and ready for our commute; we want our next-day delivery to be packed in warehouses and dispatched in postal centers. If I get hungry at 3:30 a.m. somewhere in London, I can type my order into an app and someone will bring pizza. Public services are expected to keep up: the UK’s health secretary has declared that the National Health Service should run the same level of staffing seven days a week.

“There’s been a growth of data which means employers can better predict what their demand will be and alter their labor supply to match that,” explains Alex Wood, a sociologist specializing in employment at the University of Oxford. “If employers are trying to boost their profits as much as possible by really targeting the labor on to those times when it’s profitable for clients, you then get a situation when people are only working a few hours a day.” For instance, someone working in a high-street shop might only be called in to help for the busiest part of the day.

In addition, Wood notes, trade union power has weakened in parts of Europe and the US, leading to less collective bargaining. So low-paid workers are left in insecure situations where they are not guaranteed work. Many companies have hired workers on “zerohour contracts,” meaning that they have no obligation to give them shifts, or provide benefits such as paid holiday or sick leave. “Lots of people want flexible jobs but often the reality is that, particularly in low-wage, low-end jobs, the flexibility is not for the worker,” says Wood. “It’s all for the employer.”

Russell Foster, a neuroscience professor at the University of Oxford’s Sleep & Circadian Neuroscience Institute, has spent decades working to understand the biological clocks that determine our sleep patterns. Now he is calling on employers to protect night workers. The human body clock has been calibrated over millennia to respond to changes in the natural environment — something that is forced wildly out of sync for people who regularly work night shifts. These biological rhythms are like an orchestra, says Foster: “Shoot the conductor, everybody plays at a slightly different time. So you’ve got this cacophony rather than a symphony.”

Foster accepts that you cannot put the 24-hour genie back in its bottle but he is trying to alert the world to what he sees as a growing health crisis. He entitled a recent presentation to a public health body “Sleep: We ignore this key aspect of our biology at our peril.”

In particular, he wants employers to do more to protect their work forces from future health impacts. Different people are more energetic at different times during the day: you might be an early bird or a night owl — an inclination that can be assessed by a process called chronotyping, using a simple questionnaire. “Why the hell do we not chronotype our work force?” Foster asks over tea in his cozy home in Oxford, frustration breaking through his avuncular demeanor.

Even small things can help. If employers gave night workers access to decent meals rather than vending machines, workers could avoid the metabolismdisrupted slide towards obesity.

“I don’t understand why M&S has not produced a whole line of night-worker food,” says Foster.

With studies suggesting night workers are more likely to develop cancer, Foster thinks employers should provide more regular health checks. Analysis by researchers at West China Medical Centre of Sichuan University, published in January 2018, found that longterm night work increases the risk of cancer in women by 19%.

Foster also suggests employers increase light levels in workplaces to help employees stay alert. He worries about night workers nodding off on the way home. “There’s a duty of care,” he says, after enthusing about Attention Assist, a drowsiness-detection system developed for drivers by Mercedes-Benz. “Why don’t employers provide such devices for their impaired employees?”

Sleepiness is associated with accidents — sometimes fatally. In 2010, 158 people were killed when an Air India plane overshot a runway at Mangalore, crashing into a ravine. Shortly before the attempted landing, internal recording picked up audio of the pilot snoring.

The Royal Society for the Prevention of Accidents estimates that driver tiredness contributes to up to a quarter of fatal and serious road accidents, while a study in Canada found that rotating and night shifts were correlated with higher rates of injury for workers. If companies don’t change their ways, Foster warns, they could meet a slew of litigation in future.

Need for night work will continue but there are economic reasons for encouraging a well-rested work force. Rand Europe estimated in 2016 that the US economy was losing $411 billion annually to sleepiness — some 2.3% of gross domestic product.

Some companies are promoting healthy sleep practices among their workers. For example Aetna, the US health insurance company, started a bonus scheme for staff who show they have had at least seven hours sleep per night, using a wearable fitness tracker such as a Fitbit. Nearly 17,000 Aetna employees qualified for at least one sleep incentive in 2016, and some 18,000 did in 2017, the insurer told the FT. (It declined to comment on how much the initiative had cost the company.)

Many of the night workers who spoke to the FT said they were unaware that their shifts might one day make them ill. Union representatives argue employers could do more to inform workers of the risks and help them deal with managing their sleep. “I don’t think employers do enough regarding the health risks,” says Sue Merrell, a divisional officer at Usdaw. “One of the major UK retailers has just reduced the breaks for night shifts. We’ve tried to fight it but we haven’t got a legal leg to stand on.”

Paul Evans, assistant national secretary at Bectu, the UK media and entertainment union, says that many film and TV contracts require workers to waive their rights under the European Working Time Directive. “This industry is recruiting on endurance,” he says.

Some managers recognize they have a complicated problem on their hands. Steve Corner is a manager responsible for health and safety legislation at the British Oxygen Company, an industrial gas company. The BOC has more than 30 facilities in the UK and Ireland and runs one of them — a testing facility for gas cylinders near Wolverhampton — 24 hours a day. “It’s quite expensive infrastructure,” he says. “We’ve invested in it and we want to maximize it.”

There are 20 to 25 workers on the shift at any one time, including delivery drivers. Those working nights make 10-25% more money than they would working days. Unsurprisingly, “People are very keen to be deployed on to nights,” he says.

But Corner, who spent more than two years working nights himself, is worried. He recently took part in a round-table discussion with unions and a sleep specialist from Oxford University, and was alarmed to hear research had found long-term health impacts. “Most of it was brand new to us, we’d never thought about it,” he says. “We’d historically had a desire for a night shift and we’d gone into it maybe a little ignorantly.”

Now Corner has a difficult line to tread. Reducing night shifts would be “very provocative” for industrial relations because workers would lose money. Yet, he adds, “If [working nights] has a long-term effect on your health, almost no premium is worth accepting for it.”

In terms of education about the risks, his company offers “very little, if we’re honest.”