Physiology of Electric Shock
There is always a danger of accidental exposure to an electric current through live electric wires or lightning. Exposure to electric current is harmful and can lead to serious injury or even death. Exposure to electric shock produces various physiological effects in the human body. These include pain, changes in visual acuity, locked muscles or the inability to let go, irregular heartbeat, breathing problems, and burns (Adams, 1994).
Human skin is the most resistant part of the body that prevents electric current from passing through, even though the human body is a ood conductor of electricity. However once the skin in punctured, there is little resistance against the flow of electricity through the body. The strength of current flowing through the body, the path that it takes, and the length of time that the body is exposed to it are all factors that determine the extent of injuries resulting from exposure to an electric shock. High voltage of the current, moisture content in the environment, pumping position of the heart when the exposure occurs, and the general ill health of the victim are factors that can exacerbate the physiological effects of electric shock in a human body.
The National Institute for Occupational Safety and Health NIOSH (1998) estimates that 16 mA is the maximum current an average man grasp and let go. A current of 220 mA results in paralysis of respiratory muscles, while a current of 100 mA results in irregular beating of the heart that can be fatal. A current in excess of this range results in immediate cardiac arrest and probable death.
There are many injuries that may result from electric shocks, but the major types include electrocution or death, electric shock, burns and falls. The extent of injuries sustained depends on the amount of current one is exposed to, the path that the current takes through the body, and the time for which the body is exposed to this current. The presence of water in the environment exacerbates the likelihood of electrical shock and severity of resulting injuries.