Here is some additional information on contact voltage from New York City. Again, the purpose of this is not to incite fear, but to educate people to be aware of the surroundings.
“Between 2004 and December 2009, 1014 people or pets have been shocked by stray voltage on the streets of New York City.
At the lowest level of contact with an energized object humans and animals feel no sensation at all. As the voltage increases, a tingling sensation occurs. With more voltage, this tingling becomes pain. At still higher levels muscular control is lost, making it impossible to break contact with the energized object. Burning, muscle damage and neurological damage follow. At approximately 50 volts, an adult’s heart may fail to beat and death (electrocution) may result. A small female child may die at voltages above 30 volts. In all cases: the higher the voltage the higher the probability of death; the longer the contact with the energized object the higher the probability of death; females (because of the heart’s electrophysiology) and children are more likely to die.
If low levels of stray voltage do not pose a significant risk, should street lights and manhole covers found with 1 to 20 volts be ignored? The answer is an emphatic NO. The number of stray volts found on an energized object is not constant. Any amount of stray voltage indicates frayed/exposed wiring (or some other failure) in the power delivery infrastructure. Environmental conditions, such as the amount of water or salt, primarily determine the number of volts measured, not the extent of the wire damage. One volt can quickly become 50 or 120 volts after a rain storm or a street cleaning.”