The lethality of electric current to the human body is rooted in the disruptive effects it has on the body’s physiological processes. When an electric current passes through the body, it can cause various injuries and disturbances, with the severity depending on factors such as the magnitude of the current, its path through the body, and the duration of exposure. The main reasons why electric current can be lethal for the body include:
- Muscle Contraction and Tetany: Electric current can stimulate muscles to contract involuntarily. If the current flows through the muscles responsible for breathing, it can lead to respiratory failure. This is particularly dangerous as the interruption of breathing can quickly result in oxygen deprivation, leading to unconsciousness and, ultimately, death.
- Cardiac Effects: Electric current passing through the chest can interfere with the normal electrical conduction system of the heart. This can disrupt the heart’s rhythm, leading to conditions such as ventricular fibrillation, where the heart quivers instead of pumping blood effectively. Ventricular fibrillation is a medical emergency and, if not corrected promptly, can be fatal.
- Tissue Heating and Burns: The resistance of the body tissues to the electric current causes them to heat up. This can result in thermal burns at the points where the current enters and exits the body. Internal tissues, including blood vessels and organs, can also be damaged due to the heating effect, leading to further complications.
- Nerve Damage: Electric current can damage nerves directly or by causing muscle contractions that stretch and injure surrounding tissues. Nerve damage can result in pain, loss of sensation, and impaired motor function.
- Electrolyte Imbalance: The flow of electric current through the body can disrupt the balance of electrolytes, such as sodium and potassium, essential for normal cellular function. This imbalance can have cascading effects on various physiological processes, including nerve conduction and muscle contraction.
- Internal Organ Damage: High-current exposures can cause internal injuries, damaging organs and blood vessels. This can lead to internal bleeding and long-term complications, depending on the severity of the injuries.
It’s crucial to recognize that the severity of the effects depends on the type of current (AC or DC), its frequency, and the pathway it takes through the body. Even seemingly low currents can be lethal if they pass through vital organs or interfere with critical physiological processes. Electrical safety measures, including proper insulation, grounding, and the use of protective devices like circuit breakers, are essential to prevent electric shocks and mitigate the potential lethality of electric current exposure.