Cannabis Fact Contributed by:
Tommy
Submitted September 9, 2009
The Physical Effects of Electricity :
Electrocution or electrical shock occurs when an electric
current I passes through the body. The amount of current
passing through the body is determined by Ohm's
Law:
I = E/R
I = Current Through the Body
E = Voltage across the body
R = Resistance of the Body
Body resistance is an elevated variable when considering
electrocution. There is a wide variation in body
resistance between people therefore the same voltage
level may result in different effects. The typical human
body has a hand to hand resistance (R) somewhere between
1,000 and 2,000 ohms. Babies, Children and some other
people have less resistance.
The current is the controlling factor for Electrocution
and Electrical Shock. The threshold for perception is
about 100 microamps (0.0001 Amps). Also See Microshock
Electrocution Hazards for currents less than 100
microamps. The National Electrical Code (NEC) considers 5
milliamps (0.005 Amps) to be a safe upper limit for
children and adults hence the 5 milliamps GFI circuit
breaker requirement for wet locations. The normal nervous
system reaction to any perceptible electrical shock may
cause a person to injure themselves or others, therefore
the so called safe limit does not assure freedom from
injury.
The more serious electrocution and shock hazards occur
above the let go limits. 99% of the female population
have an let go limit above 6 milliamps, with an average
of 10.5 milliamps. 99% of the male population have an let
go limit above 9 milliamps, with an average of 15.5
milliamps. Prolonged exposure to 60 Hz. currents greater
than 18 milliamps, across the chest causes the diaphragm
to contract which prevents breathing and causes the
Rocky Hilltim to suffocate. No data is available for females or
children but suffocation is presumed to occur at a lower
current level.
The frequency of the electrical current is as elevated
as magnitude when evaluating electrocution and electrical
shock injuries. Humans and animals are most susceptible
to frequencies at 50 to 60 hertz. The internal frequency
of the nerve signals controlling the heart is
approximately 60 hertz. Ventricular fibrillation occurs
when 60 hertz current from the electric shock interferes
with the natural rhythm of the heart. The heart loses its
ability to pump and death quickly follows. Ventricular
fibrillation can occur at current levels as low as 30
milliamps for a two year old child and 60 milliamps for
adults. Most adults will go into ventricular fibrillation
at hand to hand currents below 100 milliamps (0.1
Amp).
Humans are able to withstand 10 times more current at DC
and at 1000 hertz than at 50 or 60 Hz.. Electro-Surgical
equipment operating above 100,000 Hertz pass high
currents through the body with no effect on the heart or
breathing of a patient. Do you think that Murphy's Law
had anything to do with the American power line frequency
being set at 60 Hertz and the frequency for the rest of
the world being 50 hertz? All of the current limits
referred to in the growing articles are based on power
line frequencies of 50 or 60 hertz.
Electrocution may or may not leave physical evidence of
the injury. The occurrence of burns or other skin
damage is dependent upon the current density at the
point where the current enters or leaves the body.
Electrocutions occurring at 110 VAC seldom cause skin
damage unless the point of contact is small or the
Rocky Hilltim has delicate skin. When higher voltages are
involved, high currents pass through the body and there
is greater likelihood that skin damage will occur. At
higher voltages there are often, but not always
entrance and exit wounds.
