Hazards of Power Lines

America's power grid is a maze of high-voltage electrical transmission and distribution lines, 97 percent of which are strung directly overhead. The lines may be brought to Earth via severe storms, natural disasters or human error, creating a potentially deadly threat. Under normal circumstances power lines pose little danger, but debate continues over the hazards of living in close proximity to a system literally humming with intense force.

Occupational Hazards

• The National Institute for Occupational Safety and Health has reported that, on average, 128 deaths occur each year due to worker contact with power lines. These lines are not insulated and can carry loads of electricity ranging from a few hundred to more than 700,000 volts. Workers who inadvertently touch a power line with a crane, ladder or other piece of conductive equipment are in danger of severe electrical shock, burns or death. Current flows from the live wire to the metal equipment to the operator, and finally into the ground, during such accidents.

Environmental Hazards

• Scientific debate has raged since the 1970s regarding the danger of electrical fields and electromagnetic fields generated by power lines. A 1979 epidemiological study asserted that EFs and ELFs were directly linked to increased incidences of childhood leukemia, breast cancer, Alzheimer's disease, Lou Gehrig's disease and brain tumors. That study has been largely discredited, but many people still fear that living in close proximity to power lines can result in illness or death.

  The National Cancer Institute conducted its own epidemiological study in the mid-1990s and found no link between EFs, ELFs and childhood leukemia. The National Research Council agreed, stating that that fields produced by power lines had no detrimental effect on cells, tissues or organisms.

Weather and Natural Hazard

• Natural calamities such as tornadoes, earthquakes or ice storms can take down power lines in seconds, turning them into virtual death traps. The hot lines may land on people, homes or vehicles, causing fires, injuries and death. Utility companies routinely educate consumers of such dangers, stressing that a person should stay far away from any line that is lying on the ground. Even touching a downed power line with a non-conductive instrument such as a limb is dangerous, as deadly voltage can easily travel along moisture on the object, pass through the person holding it and be dispersed into the ground.