HEALTH REPORT - Lightning Safety（在线收听）

HEALTH REPORT - Lightning Safety
By Nancy Steinbach

Broadcast: Wednesday, July 21, 2004

This is Phoebe Zimmermann with the VOA Special English Health Report.

People who are hit by lightning and survive often have long-term effects. These may include memory loss, sleep disorders, muscle pain and depression.

 
Lightning striking the ground.
Experts tell people to seek the safety of a building or a hard-top vehicle any time they hear thunder, even if it is not raining. They say lightning can strike as far as sixteen kilometers from any rainfall. Lightning can travel sideways. And at least ten percent of lightning happens without any clouds overhead that you can see.

People who are outdoors should make sure they are not the tallest thing around. Bend low to the ground, but do not lie down. And do not stand near a tree or any tall object. Get away from water and anything made of metal. A car is safe, but do not touch any metal inside.

Safety experts say people in buildings should stay away from anything with wires or pipes that lead to the outside. The National Weather Service says if you plan to disconnect any electronic equipment, do so before the storm arrives. Do not use a wired telephone. Do not use water. All these can carry electricity.

Some people think a person struck by lighting carries an electrical charge afterward. Experts say this is false. It is safe to begin emergency treatment.

Each year about four-hundred people in the United States are struck by lightning. Last year forty-four people died. The average is close to seventy. The National Weather Service says that is more than are killed by severe storms.

Lightning is a release of energy in the sky. So what causes it? During a storm, the normally neutral particles in clouds hit each other. They become electrically charged. As they flow toward each other, they form an electric spark of light.

Some lightning is created within clouds. Some is created between clouds. And some is created when negative charges move down from the base of a cloud to meet positive charges rising from Earth.

Lightning strikes carry one or more electrical discharges called strokes. The bright light seen in a flash of lightning is called a return stroke. Return strokes travel at the speed of light. They discharge about one hundred million volts of electricity. They heat the air to more than thirty-three thousand degrees Celsius. Air heated by return strokes expands and produces the sound of thunder.

This VOA Special English Health Report was written by Nancy Steinbach. This is Phoebe Zimmbermann.