Lightning, a powerful atmospheric electrical discharge, is a common natural phenomenon. While often misunderstood, many wonder about the mechanics of a lightning strike and whether experiencing one can alter a person’s future susceptibility. This article explores the science behind lightning and its effects on the human body, addressing common inquiries about its influence.
The Nature of Lightning Strikes
Lightning originates from charge separation within storm clouds. Updrafts carry ice crystals and water droplets upward, colliding with graupel falling downward. These collisions transfer electrons, causing the top of the cloud to become positively charged and lower regions to accumulate a negative charge. This electrical imbalance creates an electric field.
When the electrical potential difference becomes sufficient, a rapid discharge of electricity occurs. This discharge can manifest in several forms, including intra-cloud (within a single cloud), cloud-to-cloud (between different clouds), and cloud-to-ground lightning. Cloud-to-ground strikes are the most hazardous to life and property. These strikes begin with a “stepped leader” of negative charge descending from the cloud, met by an upward-moving “streamer” of positive charge from the ground. Their connection creates a conductive path for the massive electrical current.
A typical cloud-to-ground lightning bolt carries an electric current of about 30,000 amperes and can reach voltages of several hundred million volts. This immense energy is released in microseconds. The rapid current heats the air along the lightning channel to extreme temperatures, often around 30,000 °C (54,000 °F), which is hotter than the surface of the sun. This intense heat causes the air to expand explosively, generating a shock wave perceived as thunder.
What Happens When Lightning Strikes a Person
When lightning strikes a person, the effects are immediate and severe. The electrical current can cause direct injury, burns, and mechanical trauma. The most life-threatening immediate effects are cardiac arrest and respiratory failure, as the current can stop the heart or paralyze respiratory muscles. Resuscitation efforts, such as CPR, are crucial and should be started immediately, as victims do not retain an electrical charge.
Lightning injuries can occur through several mechanisms beyond a direct strike, which accounts for only about 5% of cases. A side flash happens when current jumps from a nearby struck object to a person, accounting for approximately one-third of injuries. Ground current is the most common mechanism, where lightning strikes the ground and the current spreads outwards, affecting anyone in its path. Contact injury occurs when a person touches a struck object, allowing current to pass through them.
The intense heat generated by a lightning strike can cause burns, although full thickness burns are rare. Superficial burns, such as linear burns from vaporized sweat or fern-like Lichtenberg figures on the skin, are more common. Beyond electrical and thermal effects, the explosive force of rapidly expanding heated air can cause blast injuries, leading to ruptured eardrums, concussions, or even being thrown. Neurological damage is also a primary concern, potentially causing loss of consciousness, seizures, memory issues, and temporary paralysis known as keraunoparalysis.
Factors That Influence Lightning Strikes
The question of whether surviving a lightning strike makes an individual more susceptible to future strikes is a common misconception. A previous lightning strike does not inherently alter a person’s biological or physical makeup to increase their likelihood of being struck again. There is no scientific evidence to suggest that a person becomes a “lightning magnet” after an initial incident. The risk of repeat strikes is primarily influenced by external factors related to exposure rather than any internal change within the individual.
Repeat lightning strikes are largely attributed to geographical location and occupational or behavioral patterns. Individuals living in lightning-prone regions, such as Florida, naturally face a higher overall risk of exposure. Certain occupations involving extensive outdoor work, including construction, farming, or landscaping, increase a person’s time spent in environments vulnerable to lightning. These activities elevate exposure to hazardous conditions during thunderstorms.
Behavioral choices also play a significant role in determining lightning strike risk. People who do not seek appropriate shelter during a thunderstorm, or who engage in outdoor activities despite thunder being audible, are placing themselves at increased risk. This includes activities like golfing, fishing, or swimming during a storm. While being struck by lightning is a rare event, individuals who have been struck multiple times are typically those who frequently find themselves in high-risk outdoor situations.
Staying Safe From Lightning
Understanding lightning’s behavior is crucial for minimizing risk. The most fundamental safety rule is: “When thunder roars, go indoors.” If you can hear thunder, you are close enough to be struck, even if the sky appears clear or it is not raining. Seek immediate shelter in a safe, enclosed building, such as a home or office, or a fully enclosed hard-topped vehicle with windows closed. Avoid open structures like picnic shelters, gazebos, or tents, as these do not provide adequate protection.
Once indoors, stay away from windows and doors. Avoid contact with anything that conducts electricity, including corded phones, electrical appliances, and plumbing fixtures like sinks and showers. Lightning can travel through metal wires or bars in concrete walls and flooring, so avoid leaning on or lying on concrete surfaces.
If caught outdoors with no immediate safe shelter, certain actions can reduce risk, though no place outside is entirely safe. Move away from elevated areas like hills or mountain ridges, and avoid isolated tall objects such as trees or utility poles, as lightning often strikes the tallest points. Stay out of and away from bodies of water. If no other option is available, crouch down in a ball-like position in a low, open area, minimizing contact with the ground. After the last sound of thunder, wait at least 30 minutes before resuming outdoor activities.