Don’t rely on folklore for lightning safety

Two cloud-to-ground lightning bolts strike west of Washington, D.C. September 27, 2012 (Kevin Ambrose)

Two cloud-to-ground lightning bolts strike west of Washington, D.C. September 27, 2012 (Kevin Ambrose)

Folklore isn’t a good guide to lightning safety, but it remains a big source of advice.

Probably the most common lightning folklore is that metal “attracts” lighting. One variation is that if you’re going out to play golf don’t wear shoes with metal spikes because they “attract lightning.”

Folklore also says metal or electronic objects such as cell phones, jewelry, and the ear buds that you’re listening to music with will attract lightning.

None will “attract” lightning, but the ear buds could block you from hearing thunder, which is nature’s way of telling you to get indoors, just as they might block the blare of the horn of the truck you’re about to step in front of as you concentrate on texting.

“Metal does not attract lightning,” says Dr. Mary Ann Cooper, a leading expert on lightning injuries. “It conducts electricity. If you have spikes on shoes you’ll get burned from the spikes heating up” if lightning happens to hit you.

The idea is that rubber shoe soles “insulate” you and prevent lightning going through you to the ground doesn’t make sense, she says. A lightning flash that’s traveled through a thousand or more feet of air, which is a very good insulator, won’t be slowed by less than a half inch of rubber.

The main lightning safety rule is “when thunder roars, go indoors.” In other words if you hear thunder you should rush to get inside a building with wiring and plumbing or into a vehicle with a metal roof and the windows rolled up.

Shelters such as those found on golf courses, in picnic areas, or at bus stops are not safe refuges from lightning. Nor are dugouts at athletic fields.

Plumbing and wiring will conduct lightning that hits a building to ground. Lightning that hits an all metal vehicle will flow through the metal and jump to ground, sometimes blowing out a tire or tires on the way. When sheltering inside a vehicle you shouldn’t be touching any metal.

Once inside a building you should stay away from anything that’s plugged in to the building’s electrical supply such as appliances, computers, or lamps. You shouldn’t use a telephone with a cord that goes into a wall. A cell phone that’s not plugged into the charger is safe indoors.

You should also stay away from plumbing since lightning that hits the building or the nearby ground could follow wiring or plumbing into the building. Taking a shower during a thunderstorm isn’t a good idea.

Cooper is a professor emerita of emergency medicine, now retired from the University of Illinois at Chicago. She’s widely respected for her work on the care of lightning victims and on lightning safety. Even though retired, she’s continuing her lighting safety work in the United States and other countries.

She says some of today’s lightning folklore derives from previous lightning safety messages that research later showed are not good advice.

Probably the best example is the idea that if you are caught in the wilderness far from safe shelter you should stand inside the circle within a 45-degree angle from the top of the tallest tree around, but not too close to the tree. This is called the “cone of protection.” The idea was that lighting would be most likely to hit the tall tree, not you.

John Gookin, who is curriculum and research manager for The National Outdoor Leadership School in Lander, Wyo., says the cone of protection is a classic case “of old ideas hat have become outdated. They were good ideas based on the state of knowledge at the time but scientists have taught us a lot about lightning that helps us make better recommendations, while we also slowly discard the suggestions that appear to be statistically insignificant.”

The cone of protection works when applied to a building protected by a lightning rod or rods. It offers little protection to people in the woods. The cone doesn’t provide much protection because if lightning hits a tree the electricity will spread out across the ground. Such “ground” currents account for 40-50% of all lightning deaths.

Cooper and Gookin both stress that our best bet to avoid being hit by lightning is to keep up with weather reports and forecasts as well as keeping an eye on the weather when you’re planning to go outdoors. You want to avoid being caught far from safe shelter such as in a boat far out in Chesapeake Bay or climbing a mountain when thunderstorms move in.

The experts’ basic message is: No place outside is safe when thunderstorms are in the area.

Related:

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Ten shocking things that can happen if you are struck by lightning

Record low for lightning deaths in 2011 but tornado deaths third highest; why the disparity?

Stacking lightning bolts over Washington, D.C.

Dissecting a derecho bolt: more to lightning than meets the eye (and camera lens)

Lightning gone wild during Washington D.C.’s derecho

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