Some truths about lightning: when thunder roars, go indoors

Lightning kills…safer to stay indoors during a thunderstorm. Neale du Plooy

There are many myths about lightning. Almost all cultures on Earth have their own beliefs about what causes it.

Firstly, we need to know how to think critically about lightning. Why are there so many myths about lightning? Could it be that previous generations didn’t fully understand the complex science behind lightning? Could it be that these myths have been passed down from one generation to the next without being seriously questioned?

It is time to start thinking critically about lightning.

Lightning is a sudden natural electrical discharge of a very short duration and high voltage between a cloud and the ground or within a cloud, accompanied by a bright flash and typically also thunder.

The truth of the matter is that lightning is dangerous. It is a most consistent weather killer on earth. It kills more people than hurricanes, tornadoes or floods.

Lightning kills approximately 24 000 people around the world every year. And approximately 240 000 people will be struck or injured but survive a lightning strike, often with severe disabilities. Lightning is a completely random and anonymous killer.

Myths about lightning

Lightning injuries are always fatal - only three out of 10 die, according to a US study

Major cause of lightning death is from burns - The only immediate cause of death is a heart attack

Some one struck by lightning bursts into flames - in reality lightning flashes over the outside of a victim, leaving little external signs of injury

Lightning never strikes the same place twice - The Empire State Building is hit dozens of times a year, while mountaintops and radio-television towers get struck regularly

Umbrellas do not attract lightning - The person with the umbrella has the same risks as the person without the umbrella

Cellphones, iPods, and other electronic gadgets attract lightning - Their use prevents people from paying attention to the weather leading many to the assumption that their use attracts lightning

It is safe to seek shelter under a tree - One of the most dangerous places to stand during lightning is under a tree or near tall object

If you are not killed by lightning you will be okay - Victims suffer chronic pain, attention deficit, depression or post-traumatic stress disorder

Victims of lightning remain electrified and are dangerous to touch - A person does not retain a charge like a battery. This myth has led to unnecessary deaths due to delayed efforts to save the patient.

Ways in which lightning can kill

Deaths due to lightning are almost completely preventable if people heed the safety measures.

Lightning can strike one directly. It can also strike one indirectly - by contact with an object such as a pole or a tree that was struck directly.

Lightning can ‘side flash’ from a struck object, such as a tree, to a nearby victim.

Its current can also flow from the soil beneath. This earth current can flow up one limb and down another of the victim, which can result in injury or even death. In other words, lightning can travel through the ground like ripples on the surface of the water.

Recent research published in the South African Journal of Science explained another way in which lightning can injure people – namely lightning’s pressure blast wave.

This pressure blast wave is almost the same as that of a 5 kg TNT bomb and can injure people within 10 m of a lightning flash. This is about enough energy to blow up a concrete pavement.

Electrical thunderstorm precautions

All building structures should have a lightning conductor - nearby but not touching. Stay indoors during a thunderstorm and if you are travelling, stay in the vehicle.

Don’t continue the barbecue (braai). Practising lightning safety is never convenient. Stand under an enclosed metallic shelter if you can.

When indoors try to stay away from corded electrical appliances. It is a good idea to unplug electrical appliances when you hear thunder rumble.

Taking a bath is considered marginally safer than taking a shower during a thunderstorm.

Do not swim during a thunderstorm. Get out of the water when you hear thunder - especially if it takes 30 seconds between lightning flash and thunder bang. If it is 30 seconds or less you are in danger. Wait until there has been no lightning or thunder for thirty minutes before going back in.

If you are in a boat seek shelter.

If you are caught in the open, go inside a fully enclosed building. Avoid hilltops and don’t take shelter under lone trees.

If you are in the open playing sport, fishing, playing golf, soccer or rugby, try and find a fully enclosed metallic shelter. Rather stop the match and go indoors until the storm is over. It is better to have all members playing the game at a later stage than losing any one of your teammates.

Listen to the weather station in your area and give yourself adequate time to get home before thunderstorms arrive. Try and use social media and mobile phones to warn of impending thunderstorm activity. Invest in a lightning early warning system for severe weather to protect lives.

Lightning is dangerous. One should not tempt fate. When thunder roars, go indoors.