American Transmission Co. projects

Project website for a Wisconsin-based company that owns and operates the high-voltage electric transmission system that powers communities in portions of the Upper Midwest.

Electric and magnetic fields

It is a fact of life that we all are exposed to electric and magnetic fields. EMF is invisible fields of energy that exist around any device that carries or uses electricity. Power lines, household appliances and electric equipment, lighting and wiring all create fields. Electric fields are related to the presence of voltage, even when no current is flowing. Magnetic fields only are present when a current is carrying an electric charge through a wire or conductor.

Electric and magnetic fields increase in strength as the voltage and current respectively increases. The strength of both fields quickly decreases as you move away from the source, but magnetic fields—unlike electric fields—pass through most materials and are difficult to shield.

What the research says

Electric fields first attracted attention in the early 1970s. Studies conducted by government and industry failed to show that electric fields are harmful to human health. In the 1980s, scientists began studying the effects of magnetic fields, which can’t be felt and pass directly through the body. A few epidemiological studies—research that relies on statistics to show associations between the occurrence of disease and potential causes—suggested some possible association between magnetic field exposure and certain types of cancer, primarily leukemia and brain cancer. Today, scientists generally agree that these studies taken as a whole show no consistent association between magnetic field exposure and an increased risk of cancer.

A six-year federally mandated study that concluded in 1999 reported the following findings:

“The scientific evidence suggesting that [EMF] exposure poses any health risk is weak … the probability that EMF exposure is truly a health hazard is currently small. The weak epidemiological association and lack of any laboratory support for these associations provide only marginal scientific support that exposure to this agent is causing any degree of harm.” (National Institute of Environmental Health Sciences, June 15, 1999)

From a report from the International Agency for Research on Cancer (IARC):
“The association between childhood leukemia and high levels of magnetic fields is unlikely to be due to chance, but it may be affected by bias. In particular, selection bias may account for part of the association … It cannot be excluded that a combination of selection bias, some degree of confounding and chance could explain the results. If the observed relationship were causal, the exposure-associated risk could also be greater than what is reported.” (IARC, 2002)

At ATC, we are committed to protecting the health and safety of the public, and to providing safe, reliable electric service.

Our position on EMF

We recognize that individuals who live or work near our transmission lines and substations may be concerned about EMF. The health and safety of the public and our employees is a priority, and we are committed to providing safe, reliable electric transmission service. We will continue to use research findings to establish responsible siting practices for new electric transmission facilities. We will continue to follow the Public Service Commission of Wisconsin’s construction and siting policies related to EMF. We’re prepared to adapt our EMF policies and safety standards based on the state of the science. In the absence of EMF exposure standards in our service area, we are prepared to advise concerned customers on how they may reduce their EMF exposure, to assess the issue during real estate deliberations or to place EMFs into perspective with other everyday risks. However, given the state of the science, we do not move or remove lines or make other costly and unnecessary investments in response to fears about EMF.

We continue to work with local distribution companies to actively communicate with the public about EMF. Most utilities offer free, on-site magnetic field measurements. Contact your local electric service provider for more information about measurements and materials they may have available.