According to the calculations of the National Lightning Safety Institute, people in the U.S. have a one in 280,000 chance of being struck and one out of every 200 houses are likely to be on the receiving end of a lightning strike each year. Statistics gathered by the National Oceanic and Atmospheric Administration (NOAA) indicate that the same number of people fall victim each year to lightning strikes as tornadoes, and lightning kills more people in the US annually than hurricanes do.
A lightning bolt can kill instantly by causing cardiac arrest, with the survival rate amongst strike victims being around 20 percent. Strikes also cause permanent neurological and tissue damage, burns, infection, personality changes and kidney failure. According to NASA, lightning injuries are different from electric shocks since an industrial electrical shock ranges from 20 to 63 volts and lasts around half a second, whereas a lightning strike is even shorter in duration but delivers around 300 kilo volts.
The majority of lightning-related deaths and injuries occur in the afternoon, with victims most commonly swimming, walking in an open field or holding metal objects like fishing rods, golf clubs, gardening implements or umbrellas at the time of the strike. NOAA's advice is "If thunder roars, go indoors!" since strikes are possible as far as 10 miles from the rain area. Heading indoors or to a safe location, monitoring the weather and avoiding use of corded phones and electrical equipment is recommended. If caught outdoors during a storm, avoid open areas, tall objects and metal conductors.
Benjamin Franklin invented the lightning rod as a means for grounding the electricity of a lightning strike in order to protect buildings and people during storms. Today's Lightning Protection Systems (LPS) are comprised of the elevated rod, a series of vertical or horizontal wires and a ground rod. Since modern buildings are constructed from materials such as steel and include copper pipes, metal frames and electrical wiring, lightning may be attracted to these elements despite an LPS being in place. For this reason, the National Lightning Safety Institute recommends that priority should be given to grounding, bonding and surge protection over installation of LPS.