Part 1. High Voltage Alternating Current (HVAC)
For several decades much research has been directed at the health hazards of HVAC power lines.
It was not until 1992 that an adequately funded program was authorized by the U.S. Congress. The Electromagnetic Frequency Research and Public Information Disseminating System (EMF RAPID) was directed and managed by the National Institute of Environmental Health Studies (NIEHS), the National Institute of Health (NIH), and the Department of Energy (DOE). Their brief was to clarify the potential for health risks from extremely low frequency electric and magnetic fields.
The end result was that the strongest evidence for health risk was for childhood leukemia, and chronic lymphocytic leukemia in exposed adults.
The RAPID Program recommended that the power industry site power lines to reduce human exposure. The International Agency for Research in Cancer (IARC), in 2002, classified extra-low frequency electro-magnetic fields (ELF/EMF) as possibly carcinogenic to humans. That statement was based on pooled studies demonstrating a consistent pattern of a two-fold increase of leukemia in children exposed to magnetic fields above 3-4 milligauss (a measurement of magnetic activity). Italy defines as harmful exposure to more than 3-4 milligauss for more than four hours a day.
Children have a higher rate of cell division and have developing immune systems and are therefore at greater risk of harm from EMF fields.
The American College of Pediatrics recognizes this danger to the pediatric population.
Causation has not been proved, but numerous studies have shown an association and an increased statistical significance of the development of childhood leukemia in those children living in an environment of more than 3-4 milligauss.
The magnetic field from a heavily loaded transmission line will fall off to less than 3 milligauss about 500' from the lines.
Because of the lack of strong scientific evidence, many countries and states have adopted the Precautionary Principle* and/or Prudent Avoidance Policy*.
Spain, Sweden, UK, and Australia now prohibit the construction of high-voltage power lines withing 300' of homes or schools.
Connecticut recommends burial of lines near schools.
There are many other examples of adoption of the precautionary principle and prudent avoidance policy.
The above studies and health risk evaluations were based on studies of high-voltage AC lines.
*PRECAUTIONARY PRINCIPLE: Avoidance of unnecessary exposure to power-lines as long as there is scientific suspicion about their harmful side-effects. The precautionary principle states that if an action or policy has a suspected risk of causing harm to the public or the environment; in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking the action.
*PRUDENT ACTION/AVOIDANCE: Whereby even without any demonstrable risk. the most achievable low-cost measure will be taken to reduce EMF exposure.
Coming next in Part 2--what happens when HVDC lines are added to ROWs with existing HVAC lines?