What Are the Dangers of Overhead Power Lines?

Overhead power lines are intrinsically dangerous, as they are not insulated and carry a high voltage of electricity. Electrocution is a danger if people or the machinery they are using comes into contact with the lines. Research on the potentially dangerous effects of the electric and magnetic fields that surround power lines has also been performed, but has been inconclusive.

Electrocution by Direct Contact

• In 2009, according to the Bureau of Labor Statistics, 63 people were killed by coming into contact with overhead power lines. In 2008, more than 100 people were killed. This makes up about one percent of all occupational deaths in the U.S. (See Reference 1)

  Overhead power lines are not insulated, unlike underground power lines, and can carry more than 500,000 volts. Some power lines may appear to have insulation but this could be merely protection from the weather. Touching power lines will cause a person to become an electrical conductor (a way for the electricity to move from the power line). (See Reference Two)

  Death or injury occurs because the electric current that runs through the body interferes with heart muscle electric impulses. An intense shock such as one from a power line will stop the heart from beating. Lower level shocks can make the heart beat erratically and cause heart attacks. At the point where the contact was first made, the extreme heat produced by the electrical current will burn and blister the skin. (See Reference Three)

  Examples of when people can come into direct contact with a power line are when daredevils climb pylons, when service engineers work on lines that have not been turned off or when power lines fall in a storm.

Electrocution by Indirect Contact

• As with direct contact with a power line, anything that touches a power line will act as a conductor. Agricultural machinery, such as combine harvesters, tractors and even polytunnels, can act as conductors. Construction workers using cherry pickers, ladders and cranes can accidentally touch the lines.

  Even when the current is running through the vehicle that is touching the lines, the person inside in the cab may be unaffected, as they are insulated through the floor of the cab and the seat. However, when exiting the vehicle, if they touch any part of the electrically charged vehicle such as metal steps, they can still get electrocuted.

Flashovers

• Flashovers can also occur, when people or objects are close to, but not physically touching, the lines, but the current can jump the small gap to the person or object and use them as a conductor, causing electrocution.

Living near Power Lines

• There has been much research into the health effects of living under or near power lines. Studies have analyzed the electric and magnetic fields (EMF) that surround power lines and compared them with cancer rates in the area. The Environmental Protection Agency states that the studies have not shown a significant correlation between cancers and EMF, and that the evidence is weak. The National Institutes of Health's National Institute of Environmental Health Sciences (NIEHS) studied research in 1998 on childhood leukemia and found that power lines were a possible cause of this illness. (See Reference 5) Conversely, an English study published in the Lancet in December 1999 found no correlation between EMF and a sample size of 3,838 cases of childhood cancer. (See Reference 6)