Evaluating electromagnetic field implications of a transmission-line moratorium

A moratorium on new electricity transmission lines has been proposed in several states because of the potential health effects of electromagnetic fields. Such a policy would remain in effect until health effects are either found to be insignificant or understood and mitigated. To examine this policy, we develop a simple model to compare either doubling the current on an existing transmission line or adding a second transmission line in a separate corridor to transmit the same amount of electricity between two locations. The results indicate that the two lines will often reduce both the average exposure to electromagnetic fields and the number of exposures to higher level fields, as well as spread the exposure in a potentially more equitable fashion. The implications for more realistic situations are that building new transmission lines may often reduce any potential health effects. Hence, a transmission-line moratorium may be counterproductive.