from http://amasci.com/emotor/zapped.html
"Static" electricity ( more correctly called "net electric charge" ) appears whenever the normal quantities of positive and negative electricity in a substance are not perfectly equal. Normally the positives cancel out the negatives, and everything behaves electrically "neutral." No mysterious sparking. But if you ever end up with more negative than positive, or with more positive than negative, then you have a charge-imbalance on your body. You will get zapped the next time you touch a large metal object.
Exactly how can this imbalance occur? Whenever we walk, the soles of our shoes steal some negative charge from the floor. We leave behind electrified positive footprints, and our bodies aquire an overall imbalance of negatives. After many footsteps, our bodies attain a high level of electric charge and a high voltage. Body-voltage can easily rise to several thousand volts, and the next time you touch someone else... ZAP!, the imbalanced charge gets shared between you and the other person. The spark is painful because it's extremely hot. It drills into your skin like a white-hot needle, creating a microscopic burned area.
SOME CURES
The simplest cure: before touching a doorknob, a car door, etc., first touch it with a metal car key. The fiercely hot spark will blast the tip of the metal key rather than blasting your sensitive fingertip, and it will painlessly discharge your body's charge. (Grip your keys firmly so no spark appears between the keys and your skin.) Once you've been discharged, you can safely grab the doorknob. However, if you walk around some more, or if you sit upon a plastic car seat, you'll again need to use the keys discharge yourself.
To prevent sparks entirely, we must somehow stop the charge separation process. This can be done by:
* Changing your shoe soles to another type (try leather)
* Raising the humidity in the room
* Spraying carpets, floors, and chairs with an antistatic coating
* Installing a balanced-polarity ionizer fan
* Wearing metal-coated shoe soles (try alum. foil, but it's slippery)
* Wearing a grounded wire connected to a wrist strap
As with the car keys, the problem can also be prevented by discharging your excess body-charge in some way that doesn't cause pain. This can be done by:
* Grabbing the metal car door as you climb out of the car.
* Holding your car keys, a coin, or a metal pen, touch it to grounded metal objects.
* Knocking your knuckles against doorknobs (fewer nerve endings, less pain.)
* Wearing a metal thimble, touch it to grounded objects.
* Installing conductive carpeting, then wearing an ankle-strap w/shoe plate.
Simple solution: whenever sparking is possible, carry a metal object such as a pen or a set of keys. Hold them firmly and use them to touch any large metal objects. If the spark is blasting the end of your car keys, then it isn't burning a hole in your finger. And right after the spark has occurred, you can grab that metal without a problem.
For car-door sparks: if you touch the metal shell of the car as you climb from your seat, there will be no high-voltage buildup and no painful spark. This is good news for the passengers in your car who might not be carrying any keys or coins.
DANGER: GASOLINE FIRES. What happens when you climb out of your car at the gas station? Usually you'll zap yourself on the car door, or on the gas pump handle, or on the metal door that covers your gas cap, and usually nothing bad happens. However, suppose your passengers climb out of the car just as you're unscrewing the cap, or just as you jam the gas pump nozzle into your tank? The whole car becomes momentarily charged. ZAP! Or, suppose you turn on the gas pump and then climb back into your car. When you climb out again, you body is highly charged from the car seat. The very first thing you do is to reach into the cloud of gasoline vapors to grab the metal handle of the gas pump. ZAP! FOOSH! This obviously is a very rare event. However, it does occur sometimes, especially in the winter.
What you have to do and the way you have to do it is incredibly simple.
Whether you are willing to do it, that's another matter.
- Peter F. Drucker