March 12, 2012
Daylight Saving Time Only Benefits The Oil and Gas Industry, Not Our Health
We give up an hour of sleep every March, but why? Daylight saving time (DST) is intended to make the best use of the longer daylight hours, or so they tell us. For nearly a century, about 70 nations have been springing forward and falling back. Are there really any benefits?
Not really. Whether or not we should get that extra sleep has spurred some passionate debate from many disparate groups.
A study, published in 2007 in the journal BMC Biology, combined surveys from 55,000 people in central Europe with data on 50 individuals' sleeping and wakefulness patterns for eight weeks around the shifts to and from daylight saving time.
The researchers found people never fully adjust their circadian rhythms to the hour shift associated with daylight saving time (or, as it is known in Europe, summer time). Springing ahead by an hour, however, was most difficult for night owls -- people prone to wake up and go to sleep late, they found.
To better understand the situation, it’s best to look at why we do this annual clock change each fall and spring. Agrarian cultures built their societies around sunlight, waking up with the sun to toil in the field and heading home as the sun lowered beneath the horizon. But the Industrial Revolution, and electricity in particular, brought the freedom to unshackle us from nature’s clock.
As far back as 1897, countries began instituting daylight saving time, adding an hour of sunlight to the day. This meant communities could be more productive -- people could work longer, and when work was done it was still bright enough to run errands and stimulate the economy. The added daylight also meant more exposure to vitamin D and the added time for people to¬†exercise outdoors.
World War I was the catalyst for many countries adopting Daylight Saving Time, as the potential for energy savings was attractive. Germany and Austria were the first, in 1916, followed quickly by Belgium, Denmark, France, Great Britain, Italy, Luxembourg, Manitoba, Netherlands, Norway, Nova Scotia, Portugal, Sweden, Turkey, and Tasmania. Australia and Newfoundland joined in in 1917, and the United States was a relative latecomer, beginning Daylight Saving Time in the spring of 1918. However, it was so unpopular it was repealed the next year, and though some cities and states retained the practice, it would not become national law again until World War II.
Daylight Saving Time has a long history of controversy, with vehement opinions on both sides of the debate. It is notoriously unpopular among farmers, who already have to deal with darkness in the morning and whose animals do not readily adjust to the clock change. Some people enjoy the increase of daylight in the evening, while others are annoyed by the darker mornings.
Michael Downing, a teacher at Tufts University and the author of “Spring Forward: The Annual Madness of Daylight Saving Time,” says messing with the clock doesn’t really save energy. “Daylight saving is still a boon to purveyors of barbecue grills, sports and recreation equipment, and the petroleum industry, as gasoline consumption increases every time we increase the length of the daylight saving period,” Downing told MNN. “Give Americans an extra hour of after-dinner daylight, and they will go to the ballpark or the mall -- but they won't walk there.”
There’s data to back him up. A report by the California Energy Commission’s Demand Analysis Office concluded that increasing daylight saving time “had little or no effect on energy consumption in California.”
It doesn’t look like those issues with springing forward and falling back will end soon. As part of the Energy Policy Act of 2005, the U.S. Congress pushed daylight saving time three to four weeks deeper into the fall in an effort to combat growing energy problems, or so they say.
Another much smaller study, published in 2008, also found evidence that one's status as an owl or a lark mattered. After examining the sleep cycles of nine volunteers, researchers suggest the transition into daylight saving time in spring was more problematic for owls, while the transition out in fall was more problematic for larks, they write in the journal BMC Physiology. [Life's Extremes: Night Owl vs. Morning Lark]
It seems clear the hour time shift can interfer with sleep. And sleep problems have been associated with everything from disasters, such as the Chernobyl nuclear accident and the Challenger space shuttle explosion to health problems, such as obesity and psychiatric problems.
Data from the U.S. National Institute for Occupational Safety and Health did show an increase in the number and severity of workplace accidents the Monday after the switch to daylight saving time. On that Monday, workers slept an average of 40 minutes less than other days, the researchers write in a study published in 2009 in the Journal of Applied Psychology.
Is daylight saving time a fait accompli or will time ever just stand still? Downing doesn’t see a light at the end of the tunnel. “Since 1966, every 20 years, Congress has given us another month of daylight saving. We're up to eight months now,” he says. “And there is every reason to believe that the [U.S.] Chamber of Commerce, the national lobby for convenience stores -- which account for more than 80 percent of all gasoline sales in the country -- and Congress will continue to press for extensions until we adopt year-round daylight saving.
The most important consideration of DST should be its effect on health. In societies with fixed work schedules it provides more afternoon sunlight for outdoor exercise but that flips in the winter. It alters sunlight exposure; whether this is beneficial depends on one's location and daily schedule, as sunlight triggers vitamin D synthesis in the skin preventing a myriad of diseases. Sunlight strongly influences seasonal affective disorder so those affected experience many symptoms in the winter months due to DST.
Clock shifts disrupt sleep and reduce its efficiency. Effects on seasonal adaptation of the circadian rhythm can be severe and last for weeks. A 2008 study found that male suicide rates rise in the weeks after the spring transition. A 2008 Swedish study found that heart attacks were significantly more common the first three weekdays after the spring transition, and significantly less common the first weekday after the autumn transition. The government of Kazakhstan cited health complications due to clock shifts as a reason for abolishing DST in 2005.
April McCarthy is a community journalist playing an active role reporting and analyzing world events to advance our health and eco-friendly initiatives.