What Causes Electric Shock?
Children, adolescents, and adults are prone to high voltage shock caused by mischievous exploration, exposure at work, to man-made electrical items. About 1,000 people in the United States die each year as a result of electrocution (death caused by electric shock), which is far more than deaths caused by lightning. Most of these deaths are related to on-the-job injuries.
Many variables determine what injuries may occur, if any. These variables include the type of current (AC [alternating current] or DC [direct current]), the amount of current (determined by the voltage of the source and the resistance of the tissues involved), and the pathway the electricity takes through the body.
Low voltage electricity (less than 500 volts) does not normally cause significant injury to humans. Exposure to high voltage electricity (greater than 500 volts) has the potential to result in serious tissue damage. Serious electrical shock injuries usually have an entrance and exit site on the body because the individual becomes part of the electrical circuit.
If a person is going to help someone who has sustained a high voltage shock, he or she needs to be very careful not to become a second victim of a similar electrical shock. If a high voltage line has fallen to the ground, there may be a circle of current spreading out from the tip of the line, especially if the earth is wet or if the voltage line contacts water. The best and safest action is to call 911 or activate the emergency response system in your area. The electric company will be notified so the power can be shut off. A victim who has fallen from a height or sustained a severe shock causing multiple injuries may have a serious neck injury and should not be moved until emergency medical personnel arrive.
Children are prone to shock by the low voltage (110-220 volts) found in typical household current. In children aged 12 years and younger, household appliances, electrical cords, and extension cords caused more than 63% of injuries in one study. Wall outlets were responsible for about 15% of injuries.
Lightning injuries occur infrequently, but cause an average of 35 deaths per year in the U.S. Although there are about 8 million lightning strikes per day on earth, few people are struck and/or killed. Lightning is an environmental form of electric shock that may or may not show external burns, but lightning can injure or kill due to cardiac or respiratory arrest. Neurologic injury is common in individuals struck by lightning. Other injuries are due to severe muscle contractions triggered by the electricity. Indirect injuries caused by lightning strikes can occur with trauma from explosive forces (for example, tree sap and fluid being superheated and trees blown apart due to steam pressure generated when lightning heats up tree sap) or from the electrical charge from lightning dissipated through water and/or the earth.
Flash injuries occur when electrical energy only travels to the skin; indirect injuries caused by man – made electrical devices and lightning strikes may be caused by flame due to clothing catching on fire.