In a storm, lightning is a real danger. Every year in France, it affects between 200 and 300 people, causing almost 30 deaths. What to do to avoid lightning? In a house ? What are the effects on humans in case of lightning and what to do when it happens?
On average, since 2000, Every year 453,000 lightning strikes are detected on the ground in mainland France and 260 stormy days a year, indicates Meteorology France. Friday 3, Saturday 4 and Sunday 5 June 2022“the context is favorable for the development of storms in much of the territory. It is possible that these storms are sometimes virulent with hail, very strong gusts of wind and brief but intense rains. On Monday, June 6, the weather will be mixed, but the risk of severe storms will have receded“, details the Météo France site. In the event of thunderstorms, lightning it is a real danger. Every year in France, it affects between 200 and 300 people, causing almost 30 kills. How to protect yourself from that? What effects on the body? Tips from Michel Koutmatzoff, president of the Lightning Protection Association.
Definition: what is lightning?
The lightning corresponds to an electrical discharge that usually occurs during a thunderstorm. This electrical discharge can form within a thundercloud, called a cumulonimbus, between two clouds, or between a cloud and the ground, thus causing a flash and detonation. Due to the friction between water droplets, crystals and ice grains stirred by clouds, electrons (negative electrical charge) are formed, which are attached to the heavier elements accumulated at the base of the cloud. At the same time, the lighter ice crystals are attached to the upper part of the cloud and constitute a positive electrical charge. It is this difference in electric potential lightning is born. And depending on how far away you are from the beam, you may hear a short, powerful snap or thud.
A person standing in an open area (stadium, field, meadow) is a prime target for lightning.
Who is at risk of being struck by lightning?
The electrical charges from the thundercloud seek to reach the ground as quickly as possible. Therefore, the lightning tends to mainly target the elements closest to the clouds. logic: the higher an element is, the thinner the layer of air that passes through the electrical discharge. This is why trees and tall buildings are the first elements affected by lightning. A person standing, especially in an open area, is also a prime target for lightning. In addition, a climber who is often on summits or ridges is especially exposed to lightning strikes.
What are the effects of lightning on humans?
The effects of lightning on human beings depend on the form in which it reaches them, the intensity of the electric current and the duration of its passage through the body.
A person can be directly affected by the electric shock. Specifically “electrical current enters the body through a point of impact (the entry point which is usually in the upper part of the body) and exit through the exit point (which is usually found in the lower part of the body) to get to the ground as fast as possible“, explains Michel Koutmatzoff. A single landfill can contain up to 100 million volts and 200,000 amps, which is particularly dangerous for the organism. “This is the most violent lightning mode. This electrical discharge, in the same way that we stick our fingers in a socket, can cause cardiac arrest, internal burnsand, in 10% of cases, the death of the person as a consequence“, emphasizes the president of the Lightning Protection Association.
touch voltage lightning
A person can be struck by lightning after touching a metal object (pole, fence, etc.). Specifically: the human body is in contact with a struck metal object. So from metal and the human body are conductors, the electric current of the lightning is transmitted to the human body through the metal object. “Depending on the intensity of the lightning and depending on the organs crossed, the passage of electricity in the body can directly or indirectly cause skin burns (ranging from more or less severe superficial burns to necrosis of muscle or bone tissue), heart and disorders nervous system (ranging from loss of consciousness to head trauma, including coma with brain damage), organ damage, and mechanical damage due to violent muscle contractions and falls“, indicates our interlocutor.
A person whose feet are in contact with the ground can be struck by lightning. This can occur, in particular, if the person is sheltering under a conductive structure, such as a tree or a tent, that has been struck by lightning. This is called a “side flash.” Specifically: the difference in electrical potential between the conductor and the individual’s head increases and causes a dielectric breakdown (that is, it does not conduct -or does so very little- electricity but allows electrostatic forces to be exerted) of the air. The health consequences are the same as those of a direct lightning strike. These accidents can occur outside, but also in a home, through a fixed telephone after the lightning of the external telephone line. This risk of lightning strikes is favored by collective lightning strikes in the open air with spread from one person to another.
step voltage lightning
A person walking or standing on insufficiently insulated ground can be struck by lightning. This is called a “step voltage” strike. Specifically: lightning strikes the ground and the electric current spreads along the ground, especially around the point of impact. Thus, the electric current very quickly passes through the person’s body or flows over the person’s skin. “Again there is a increased risk of superficial or deep burns (shaped like fern leaves)as well as a risk of cardiac arrestsays Michel Koutmatzoff. let’s not forget the psychological and neurological complications, which we tend to neglect, because they are invisible and often delayed. Psychological follow-up may be necessary depending on the person’s post-traumatic stress. In fact, the person struck by lightning may not remember the accident or be depressed for months after the lightning strike.
A person can also have indirect sequelae linked to lightning without being struck down. Can be trauma related to the fall or projection of elements affected by lightning, sound trauma related to lightning noise (especially frequent above 120 decibels), eye injuries caused by lightning, gait disorders related to neuromuscular alterations…
Never take shelter under a tree!
When the sky begins to roar, here good habits to adopt :
- Never take shelter under a tree, especially if the tree is isolated or just part of a small group of trees. The risk of being hit by a lone tree is 50 times greater than that of a man standing.
- If lightning strikes in the middle of the forest, you should move as far away from the trunks as possible and avoid being near low branches.
- In open spaces, such as a field or meadow, do not carry objects, particularly metal, pointed and elongated, above your head, such as an umbrella, pitchfork or golf club. These so-called “electrically conductive” parts must be lowered or, ideally, placed on the ground, flat.
- Don’t shelter under an umbrella.
- People in groups must keep a distance of at least 3 meters from each other, to avoid the risk of side flash between two people.
- Stay away from all metal structures such as pylons, poles, fences, so as not to be the victim of a electrocution by “contact voltage”.
- Don’t stand with your legs apart or take long strides when you’re in a thunderstorm. The lying position, with your legs folded over you and covered with a raincoat or any insulating plastic material, is still the least risky position.
- Take shelter in stone shacks, a church, a chapel, or a closed car (except convertible, sunroof, or plastic models). On the other hand, avoid sheltering in a shed with a tin roof. In this case, remember to fold or retract the radio antenna.
- In a house where internal lightning protection has not been specially created (even if the house is equipped with a lightning rod), avoid touching metal parts such as water pipes and faucets, as well as machinery, electrical appliances (washing machine, dishwasher). .
- Do not bathe or shower during lightning.
- In the absence of protective devices such as lightning rods, it is strongly recommended unplug the AC power cord and antenna cable from a TV and keep them at least one meter away from the TV. An unprotected and unplugged TV can actually “implode” during a power surge, posing a risk to people in the same room.
- In case of a storm threat, avoid calling with a landline, except in case of a serious emergency. Prefer mobile phone : its volume, even if metallic, is still insufficient to exert an attractive effect on lightning.
What outdoor activities should you avoid?
In general, it’s best to avoid certain outdoor activities that are known to be particularly dangerous in stormy weather: fishing, swimming, boating, cycling, golf, mountaineering. Keep in mind that water activities are particularly at risk: a wet body is a good conductor of electricity and increases the risk of lightning strikes. Electrical work or roof repairs are also prohibited because they expose you to direct lightning strikes. Before undertaking this type of activity, it is advisable to find out about the weather conditions, for example, from Météo France and the national Météorage network.
Person struck by lightning: what to do?
Anyone struck with certain symptoms such as tingling in extremitieslimb paralysis, amnesia, eye damage, confusion, severe post-traumatic stress, apnea-like shortness of breath, or loss of consciousness should to be taken to the emergency room. “If you witness a lightning strike, immediately notify the samu calling 15 or 112 with a mobile phone“, insists the expert. Be careful to indicate to your interlocutors if the victim is conscious, if he is breathing and if he feels his legumes. “The medical help will tell you the procedure to follow while waiting for help to arrive and depending on your condition. (cover the person, put him in side safety positiondo a heart massage if you are not breathing) ”, concludes the specialist.
Thanks to Michel Koutmatzoff, president of lightning protection association. Interview on July 27, 2019.
Learn more about storm protection tips at the website of the Ministry of the Interior