When Things Go Wrong

On September 12, 1963, on the nightshift (9:30 p.m.), an A-4D jet fighter crashed into the Coney Island Rail Yards. The massive jet missed hitting any trains in the yard. The pilot, too, was unharmed, bailing out and landing in a Brooklyn parking lot on Avenue U.

Accidents like this, in the air and on the ground, seem to happen more often after dark.

In 1918, what many still call the city’s worst subway accident occurred on November 1. The motormen were on strike. A dispatcher filled in. Moments before 7 p.m., the inexperienced dispatcher driving the train lost control while entering a tunnel. Almost one hundred rush-hour commuters lost their lives. Two hundred more were injured.

Nearly eighty years later, on June 5, 1995, a similar accident occurred in Brooklyn. A Manhattan-bound M train stopped on the Williamsburg Bridge. Along came a Manhattan-bound J train. At 6:12 a.m., the J train ran into the M train. The motorman of the J train, on the last run of his nightshift, was killed. Fifty passengers were injured.

In Chapter 12, “Everyone Is The Same Down There,” we profile George, a nightshift MTA conductor. He talks about the importance of having a live conductor on the train, especially when something goes wrong. And things do go wrong. Especially on the nightshift.

Why? Well, one answer, which I’ve written about in other posts, relates to circadian rhythms. The body needs roughly twelve hours of light and twelve hours of dark, and it’s difficult to get that on the nightshift. But there are other, equally important reasons. There’s the issue of fatigue, which can happen even during the daylight hours. There’s the issue of shift changes, and the information that gets lost between shifts. There’s the issue of the lack of management personnel on the nightshift, so that those with the authority and expertise to solve problems are often not there. And there’s also the issue of a weak safety culture, where it’s frowned upon to report small problems or follow basic safety procedures.

So what caused U.S. Navy pilot Lieutenant William A. Gerrety to crash his jet fighter into the Coney Island Yards back in 1963? Circadian rhythms? Fatigue? Information lost during shift change? Lack of management personnel? Weak safety culture? All of the above?

Turns out, none of the above. The jet was struck by lightning.

Nightshift Chicago

Next week, we’ll be reading and signing books in Chicago. Why Chicago?

As in New York City, lots of people in Chicago work the nightshift. Last year, in Chicago, 171,279 people left for work between 4pm and 4:59 a.m. That’s 11% of the city’s total workforce. As in NYC & all over the world, these nightshift workers struggle to maintain relationships, eat right, exercise and, above all, sleep.

Not surprisingly, researchers at Chicago’s Rush University Medical Center have just published an article in Sleep on, well, sleep. Much research suggests that nightshift workers need to stay on a nightshift schedule, even on nights off, to mitigate the harmful effects of working nights. But this study, by lead author Mark Smith, suggests that it’s possible to mitigate these effects even if nightshift workers choose to sleep nights when they’re off work. How? With a strict regimen of light and dark to help partially delay the body’s natural circadian clock. For the full article (registration required), click here. For my other posts on sleep and the circadian cycle, see The Body's Clock and The Daysimeter. And remember, it’s not only shift workers who need to pay attention to daily doses of light & dark. It’s anyone struggling with depression, seasonal affective disorder, or the blahs when night falls earlier and earlier each day.

Ok, so you don’t work nights or mind the increasingly early nightfall but you still live in Chicago. Check out the exhibit, IN THE DARK, at the Nature Museum in Lincoln Park, 2430 N. Cannon Dr., Chicago, IL 60614, 773.755.5100, www.naturemuseum.org . Learn more about how worms, bats, butterflies and, yes, humans interact with darkness.

Finally, our book event is on Friday Dec 19 @ 7pm, at The Book Cellar, 4736-38 N. Lincoln Ave, Chicago, IL 60625, 773.293.2665, www.bookcellarinc.com. We're billing it as a night of holiday shopping and bar hopping in the Lincoln Square area, starting at 5pm, then the book event at 7pm, then a pub crawl starting at 9pm. Hope to see you there!

The Daysimeter

Nightshift workers have known for years that working nights and sleeping days can wreak havoc on the body’s internal clock. But scientists are just now catching up with some useful technology that might help reset that clock. Here’s an excerpt from an article Cheryl wrote for Scientific American, published online last week:

In an effort to gauge exactly how light affects our body clocks, Rensselaer Polytechnic Institute's Lighting Research Center (LRC) in Troy, N.Y., has developed a device called a Daysimeter. Small and ear-mounted—like a wireless cell phone headset—it has three sensors that measure head movement, bright light (or lux, a measurement of the light used for daytime vision), and blue visible light (also known as circadian light). Circadian light—radiated by the sun as well as computer and television screens—helps balance certain hormones and neurotransmitters in the body, but only in specific doses and at certain times of day. Too much of this light can throw off the body's internal clock, which researchers believe leads to problems such as fatigue and poor health…

"We envision the Daysimeter, along with other biological markers [such as hormones] will allow us to get a more detailed circadian profile of a particular person," says LRC director Mark Rea, a Rensselaer professor of cognitive science. Researchers can measure the effect of circadian light exposure on hormone levels through blood samples collected from subjects. "We're fully expecting that we'll see variation among the population," he notes.

Rea envisions "real-time light prescriptions" to help people receive or avoid light at the appropriate times. Simple measures to control when and how much circadian light we receive could help nightshift workers stay alert on the job and sleep more effectively during the day, help cure jet lag, decrease depression, and generally help everyone get a proper night's sleep.

The ability to modify circadian rhythm could potentially mitigate the negative health effects that some researchers believe are brought on by disruptions to the light-dark cycle. Recent studies have found a link between health and changes in the natural circadian rhythm. The Journal of the National Cancer Institute published a series of articles, for example, that showed night shift workers had a higher incidence of breast cancer; and, last year, the World Health Organization's International Agency for Research on Cancer cited night work as a potential breast cancer risk factor…

Rea admits the LRC is a long way off from making their instrument available to the public. But researchers in the science of circadian rhythm are excited by the prospect of devices that may one day help people understand their own particular light-dark cycle and how to keep it in balance.

For the full article, click here: www.sciam.com

Watch out!

Pedro makes deliveries on his bicycle all night long. “It’s very dangerous,” he recognizes. He’s enjoying a slow moment on this Tuesday night at 3 a.m. “Just now, a taxi that was parked darted out into the street and I almost hit it. This happens all the time. Once on 31st street I hit a car. Another time on 11th Avenue also.”

While these near-misses could be the fault of the drivers or happen as easily during the day, many accidents and injuries happen on the nightshift.

On Wednesday, June 4, a nightshift worker in an auto factory in Luton, England, got trapped in machinery at 5:30 a.m., remained trapped for an hour and a half, but survived. The week before, on Friday, May 30, a nightshift worker in a plastics factory in Redruth, England, was in a fatal accident at 4:30 a.m.

And then there are the bigger disasters: Nuclear accidents at Three Mile Island, Pennsylvania in 1979 (4 a.m.) and Chernobyl in 1986 (1:23 a.m.) The 1984 chemical leak in Bhopal, India (12:40 a.m.) killed 2,000 and injured 200,000 people.

Medical errors also increase at night. Here’s a recent New England Journal of Medicine article about adding doctors to the nightshift to prevent errors. (Or the Wall Street Journal article about it if you’re pressed for time.)

After spending a year on the nightshift shadowing everyone from waitresses to ICU doctors, it’s clear that the slower pace and calming quiet of NYC at night has its immense benefits.

However, it’s also clear that the night can be treacherous. Circadian rhythms are at their lowest around 3 a.m. Sleep debt accumulates more quickly than you might think (some studies say cognitive performance drops by 30% with one night of lost sleep, and 60% with two nights). And the information lag that can occur between shifts, as one employee’s shift ends and another’s begins, can lead to catastrophic errors.

But there’s hope! Scientists are working on ways to make nightshift workers more alert at night and enjoy more restorative sleep during the day. Stay tuned for more on that.

Meanwhile, let us know what you do to stay awake on the nightshift.

The Body's Clock

Cliff the Cabbie turns north on Third Avenue. Like most nightshift cab drivers in New York City, his shift runs 5 p.m. to 5 a.m. Tonight he wears his favorite leather jacket, a loose-fitting shirt and jeans. With a lilting Jamaican accent and full-throated laugh, he talks about working nights. "It's not normal, because your body is not made to work at night. You’re supposed to be sleeping at night and working in the daytime. It’s not normal.”

Cliff doesn't refer to circadian rhythms by name, but that's what he's describing. The word circadian, from the Latin, translates roughly as "about a day." Circadian rhythms control almost everything that happens in our bodies in about a day. They control body temperature. They control digestion. They control the release of hormones, such as melatonin, which is released at night and regulates sleep. It works like this. The eyes receive information about what time it is from the amount of light absorbed by the retina. The retina sends this information to the group of cells in the hypothalamus known as the SCN. The SCN passes on that information to the teeny tiny pineal gland in the epithalamus. If it's night time (or there isn't enough light for the retina to think it's daytime), that little gland secretes melatonin, which makes Cliff tired. Whenever we feel tired, or hungry, or thirsty, it's because our circadian rhythms think it's time to be tired, hungry, or thirsty.

For those who work regular overnights, or alternating shifts, all this messing around with the body's circadian rhythms can quickly cause health problems. Digestion problems are especially probable because the G.I. system is so sensitive in general but all the more so at night when the body thinks you're asleep. It only took us a few weeks on the nightshift to crave pancakes at 3 a.m. instead of salad, and to convince ourselves that pain in our guts from the salad meant we shouldn't order it next time. Needing to sleep during the day, we, and millions of others, skipped exercise in favor of sleep. Thus for those who work nights there are correlated increases in diabetes, obesity, heart problems, and depression. Then there are decreases in memory, cognitive functioning, immune functioning, and coordination. In December, 2007, the cancer wing of the World Health Organization weighed in on a long-debated issue by adding the nightshift to its list of possible causes of cancer.

Add to that sitting in a taxi 12 hours a night, and Cliff the Cabbie found himself rather overweight. "You have to plan some time to go out and exercise when you’re off," he says. "If you don’t do that, you’ll gain a lot of weight. That’s what happened to me." Cliff the Cabbie started taking brisk walks two or three mornings a week after work. At first, his legs hurt so badly he could barely walk. He kept at it. "After about two or three months," he says, "I went out to walk and there was no pain." Within four months, he realized he'd lost weight. "I dropped off a good 15 or 20 pounds. Just walking at a brisk pace." Once it grew cold again, he stopped his walks -- and put back on some of the weight. But he's committed to getting in shape. And he's committed to the nightshift. Don't even talk to him about the dayshift. “It’s too much stress," he says. "You eat a lot of pollution, too. I can’t do it anymore. I’ll take my chances on the nightshift.”