Trails are often built in utility corridors with electric power lines overhead. Over the years some articles have raised concerns, apparently unfounded, about electromagnetic fields (EMF) emanating from power lines. From an operational perspective, EMF is not an issue for trail activities. Trail users are destination oriented, so their exposure is limited. Over 25 years of research and hundreds of millions of research dollars from groups including the World Health Organization, the National Cancer Institute, and the International Agency for Research on Cancer have come to the following conclusion: There are no known adverse health effects associated with low levels of static electric or magnetic fields such as those associated with DC transmission lines. Most studies conclude that health risks from inactivity greatly outweigh any risks to trail users from EMF exposure. Duke-American Transmission Co., a joint venture partnership between Duke Energy and American Transmission Co., offers an understanding of electric and magnetic fields: Duke Energy Ocular Melanoma EMF Fact Sheet Duke Energy Electrical Safety