When I put 2 electrodes into a electrical conductive solution, does the volume of the solution around the electrodes have biological effect? Media these days give me a common sense that it is able to hurt someone if they step on a wet floor with a electric cord dipped in, several movies have this scene.However, I wonder if I set up an experiment like this: I put 2 AC electrodes enough to have biological effect (shock) into a container of electrical conductive solution (salt solution for example), does the volume around the 2 electrodes (and somewhere in the container but not between 2 electrodes) have biological effect or electrical current only present in the distance between 2 electrodes? What if I repeat the experiment using DC electrodes?
 A: The general answer is "yes". There is a current flow through the solution and if you put part of yourself into it then part of the current will flow through you. How much current is the real question, and that depends on a whole lot of variables such as voltage and current between the electrodes, their separation, where you place the biological component, its conductivity and how big it is. Suffice to say, people have died after a mains powered domestic appliance has fallen into their bath. That means they get at least 10mA through the heart. OTOH, if you stand on a wet floor and a live mains cable drops onto it you are very unlikely to die since the current path is purely through the foot.
As an addendum, if the feet are widely spaced and a significant current is flowing it might flow between your legs and cause injury. This is generally not a problem you should expect unless under very special conditions. Those would be where very high voltage and high currents are flowing through the ground. For example, if a pylon cable comes down and shorts to ground, or there is a nearby lightning strike. In the latter case the advice is to keep you feet together to minimise the potential difference between them. That's why, in general, four legged animals fare worse than Humans in such situations.
