Epidemiology and Circumstances

Of 217 accidental electrocutions studied during a 22-yr period in Dade County, Florida, 93 were from high-voltage (>1000 V) and 108 were from low-voltage current (163). Sixteen deaths were caused by lightning. Another study showed that 39% of electrocution deaths were from low-voltage current (most frequently household voltage [171]). An Australian study of 104 electrocution deaths showed 88% from low-voltage and 12% owing to high-voltage current (181). There are about 1000 deaths from electrical injury per year in the United States (142,147, 152, 157, 159,161). Electrical burns account for 3 to 6.5% of all admissions to American burn units (142,147,148,152). About half of electrical injury deaths occur at work and the remainder at home (181).

Low-voltage injuries occur under various circumstances (e.g., use of a faulty tool or appliance, repair of electrical equipment, contact with faulty wiring or an energized object [142,163,182,183]). About two-thirds of the fatalities are to individuals between the ages of 15 and 40 yr, and there is a male predominance (174). Failure to ground tools or appliances (i.e., a conducting connection between an electrical circuit or piece of equipment and the earth or its substitute) and using devices near water are risk factors (142,181). The victim may be unqualified to do electrical work (183). High-voltage injuries typically occur in the workplace, predominantly involving men (142,147, 158,161). Electrocuted workers tend to be younger than victims in other types of occupational fatalities (148,182,184). The highest number of workplace electrocution deaths happen in the summer owing to increased outdoor activity; decreased use of heavy insulating clothing, including gloves and boots; and decreased skin resistance from sweating (181,184). Various scenarios in the workplace lead to direct contact with a high-voltage electrical source (e.g., a vehicle such as a crane contacting high-tension lines; the raising of metal poles, antennae, or ladders that touch power lines; see refs. 142, 151, 158, 161, 163, 185, and 186). The construction and mining industries have the highest death rates (182,187).

Bathtub electrocutions are associated with electrical appliances, typically hair dryers submerged in water. The installation of a ground fault interrupter has reduced this risk (161,188,189). A ground fault interrupter is designed to sense a 5-mA difference between the ground and current wires.

More than 20% of all electrical injuries occur in children (142). Young children are predisposed to low-voltage injury because of their tendency to chew on objects (e.g., electric cords) while crawling and exploring (139,141,142,145,147,152,189,190). Considerable bleeding from an injured labial artery can occur when eschar is removed some days later (139,157,189). Wires may be inadequately protected (183). Young children are also electrocuted by direct (i.e., mouth or finger) or indirect (e.g., fork) contact with electrical outlets (190).

Low-voltage electrocution must be suspected when there is a sudden death while using an electrical appliance, and analysis of the electrical equipment and wiring is required (140,161,163,184). The appliance does not need to be in the on position, as the wiring may have been faulty or the victim may have had time to turn off the appliance (161). The victim may be witnessed collapsing after crying out in pain (140,161, 163,181,184). Electrocution does occur during autoerotic activities and consensual sexual activity (see Chapter 3, Subheading 2.7.2. and refs. 169, 170, 191, and 192).

Outside the workplace, high-voltage electrocution can occur by direct contact with an intact or downed power line (163). Older children and adolescents can sustain electrical injury through misadventures with high-voltage lines (142,145,151,152,189,190,193). Contact through a conductive device, at home or during recreational activity (antenna, kite), also occurs (163,182,183,194). Electrical burns have resulted while receiving a phone call, because of arcing between a telephone line and high-tension wire that were separated 15 cm (6 in.) (155,195). Continued victim contact with a high- or low-voltage source can electrocute rescuers (139,151,196). Switching and disconnecting energized lines can lead to noncontact "flash" burns (158).

Fig. 30. Suicide by electrocution. (A) Elaborate wiring on torso secured by duct tape. (B) Exposed copper wire. Cutaneous burn discolored green. (See Companion CD for color version of this figure.)

All manners of death are possible in electrocution. A study of 220 electrocutions revealed 217 accidents, two suicides, and one homicide (163). Electrocution is an uncommon method of suicide (Fig. 30; refs. 161, 163, 181, 188, and 197-199). A timer can be used (200,201). Wires are connected from an electrical source to the skin surface (161,200). Suicidal electrocution can be staged to mask a homicide by other means (202). Homicide by electrocution is rare (161,163,197,203,204).

Lightning causes 30 to 100 deaths per year in the United States (139,152,159, 174,177). As moist warm air rises within a cold air system, cumulonimbus clouds form (164,174,176,180). Static electricity is created during this movement of particles (144,167,180). A large negative charge results in the bottom of the clouds, and the ground becomes positively charged (144,164,174,176,180). When a potential difference of 30,000 V or more exists, a leader stroke going to the ground meets an upward streamer (pilot stroke) from an object on the ground (e.g., a standing person) within microseconds (164,174,176,205). The most common setting for a lightning strike is in a thunderstorm, but snowstorms, sandstorms, and erupting volcanoes are also associated with lightning (144). Lightning strikes do occur in fair weather conditions, and the thunderstorm can be distant (167,177,206). The majority of lightning strikes are in the summer months (174). Multiple victims are possible (141-143).

Males are at greater risk for being struck by lightning because more men are involved in outdoor work and activities (177,205). Generally, deaths do not occur in well-protected buildings; however, plumbing fixtures, telephones, and other appliances attached to the outside of the house by metal conductors can indirectly injure occupants by means of side flashes (174). Individuals are at risk in open areas and partly sheltered areas (e.g., tents [174,205]). In a study from Singapore, two-thirds of deaths occurred in partly sheltered areas (205). Lightning does not always hit the highest object (174). Lightning victims do not remain electrified (139,174).

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