Behind the Forecast: Striking facts about lightning’s impact on a human body

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Science Behind the Forecast: 5 ways to be struck by lightning (5/10)

LOUISVILLE, KY (WAVE) - "When thunder roars, go indoors" or "See a flash, dash inside" are popular phrases used to promote lightning safety.

Lightning is the quick discharge of electrical energy in the atmosphere. The following boom of thunder is caused by a shock wave created by the rapid heating then cooling of the air in a lightning channel.

On average, there are about 25 million cloud-to-ground lightning flashes and around 300 people are struck by lightning each year in the United States, according to the National Weather Service (NWS). During the last 10 years (2009-2018), the U.S. has averaged 27 lightning fatalities.

Lightning contains between one to 10 billion joules of energy which can easily short-circuit the electrical signals vital for our nervous system, heart, and lungs to function. While only around 10% of lightning victims die, survivors can face a lifetime of pain, depression, neurological problems, and other health issues.

There's more than one way to get struck by lightning. In fact, there are five.

  1. The best known and potentially the most deadly is the direct strike. This occurs when a person becomes a part of the main lightning discharge channel. The current flows through the body in two ways: through the nervous and/or cardiovascular systems and over and along the skin's surface, also known as a flashover. As lightning pushes towards the skin's surface, it can push red blood cells out of capillaries and into the epidermis (the skin) causing Lichtenberg figures. Victims can suffer burns but cardiac arrest is the immediate cause of death for those who die, according to the NWS.
  2. When lightning strikes an object, the current travels outward from the strike point and along the surface of the ground; this is known as the ground current. Because of this, a much larger area is affected. The NWS states that most lightning death and injuries are caused by the ground current. Since livestock have a larger body-spans, they face a higher risk of injury or death from the ground current. This is because lightning typically enters through a point closest to the strike, travels through the body and exits at a point farthest from the lightning. This means that the bigger the distance between those two points, the greater the risk of death and injury.
  3. While metal does not attract lightning, it is a great conductor of electricity. Lightning can travel great lengths through wires, electrical outlets, plumbing, and even faucets and showers. Anything connected to these things can easily become a conduit for lightning. Meteorologists encourage the public to avoid showering, washing dishes or even washing your hands during a thunderstorm because water traveling through metal plumbing can be a very good electrical conductor.
  4. A side flash, also known as a side splash, occurs when lightning strikes a tall object and some of the current jumps to the victim nearby. Side flashes occur when the victim is within two feet of the object that is initially struck; the person basically becomes a "short circuit" for a portion of the electrical energy.
  5. Last but not least, are streamers. Streamers form as the downward stretching lightning leader gets closer to the ground. Many streamers reach upward but usually, only one streamer makes contact with the leader; this creates the bright lightning return stroke that we all recognize. All streamers discharge their electricity along with the main strike. Someone who becomes a part of a streamer can be injured or killed by the electrical discharge even though they aren’t a part of the main lightning strike.

Of the 396 killed by lightning in the United States between 2006 and 2018, 80% were men and two-thirds were enjoying outdoor activities. 70% of lightning deaths during this timeframe occurred between June and August. Indiana and Kentucky’s last lightning fatalities occurred in 2013. Two men in Madison County, Kentucky were struck and killed on August 21 while hanging tobacco in a barn. In Indiana, a man was working on a billboard in Gary when he was struck and killed. Between 2008 and 2017 there were 6 lightning deaths in Kentucky and 3 in Indiana.

So other than cardiac arrest, burns, and Lichtenberg figures, how can lightning affect your body?

As mentioned earlier a large amount of the lightning travels outside the body along the skin; this is known as a flashover. Sweat or rain on the skin can turn into steam; as this happens, the liquid water's volume increases causing a vapor explosion that can blast off a victim's clothes, lightning researcher Mary Ann Cooper explained in a CNN interview.

Mainly the nervous system is affected by the electrical current that does make it through the body, according to the National Weather Service. Those who do not suffer cardiac arrest when struck may have to deal with the following symptoms:

  • Muscle soreness
  • Headache, nausea, stomach upset and other post-concussion types of symptoms
  • Mild confusion, memory slowness or mental clouding
  • Dizziness, balance problems

Delayed symptoms may include:

  • Personality changes/self-isolation
  • Irritability and embarrassment because they can't remember people, job responsibilities and key information
  • Difficulty carrying on a conversation
  • Depression
  • Chronic pain and headaches

Some long term symptoms include:

  • Problems coding new information and accessing old information
  • Problems multitasking
  • Slower reaction time
  • Distractibility
  • Irritability and personality change
  • Inattentiveness or forgetfulness
  • Headaches which do not resolve with usual OTC meds
  • Chronic pain from nerve injury
  • Ringing in the ears and dizziness or balance problems
  • Difficulty sleeping, sometimes sleeping excessively at first and later only two or three hours at a time

Lightning can strike 10 miles away from a thunderstorm so it’s important to seek appropriate shelter even if you hear a clap of thunder or see a flash of lightning. The odds of being struck in the U.S. in a year: 1 in 700,000. Just to put that in perspective, Jefferson County, Kentucky’s population in 2010 was 741,096 according to the United States Census Bureau.

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