By GARRY RAYNO
CONCORD — The health effects of electromagnetic fields generated from high voltage electric transmission lines have been debated for decades and on Tuesday experts hired by Northern Pass said the fields generated by the project will not adversely affect public health and safety.
Others disagreed, however, and said the studies done by the experts downplay the project’s potential harm and said the highest levels of electromagnetic energy will be generated near the greatest population density in the Concord, Pembroke and Deerfield areas.
The fourth day of hearings on the $1.6 billion, 192-mile transmission project to bring 1,090 megawatts of Hydro-Quebec electricity from Canada to the New England electric grid saw counsel for the public Peter Roth spar with William Bailey, principal scientist for occupational and environmental health risk assessment at Exponent Inc., over health effects from exposure to electromagnetic fields.
Roth implied Bailey downplayed the connection between exposure and childhood leukemia in a study he did for the project, and at a public hearing in Meredith.
Roth cited a quote in the report from the World Health Organization that Bailey used and noted it was incomplete. Roth cited numerous studies acknowledging the link, and Bailey agreed with the assessment, but said several times that studies are inconclusive.
Yes, there is a link, he noted, but no agreement on what causes the link. In his Northern Pass report, Bailey stated “chance, bias and confounding cannot be ruled out as an explanation,” but Roth said it is not that simple.
“This is not case closed, this is over,” Roth said. “The link to childhood leukemia is still open.”
But Bailey said many studies indicate residents living near high voltage lines have no health effects from the electromagnetic fields. He said the exposure from Northern Pass would not reach levels that would increase the risk.
Roth said New Hampshire does not have standards for exposure to electromagnetic fields, but other states do.
He cited Connecticut standards, which were developed with Northeast Utilities’ (now Eversource) participation. He said the Connecticut agency similar to the Site Evaluation Committee adopted a policy of prudent avoidance, which means low- to no-cost changes like avoiding placing transmission lines near residential areas, schools, day care facilities, playgrounds and youth camps, should be used.
Roth asked Gary Johnson, senior managing scientist at Exponent’s electrical engineering and computer science practice, if that was done for the Northern Pass line.
Johnson said he used national standards to develop the models for Northern Pass, but indicated he was not aware where there might be schools, or other facilities near the transmission line.
He said the electromagnetic fields projected for Northern Pass are well below existing standards at the edge of the right of way.
Roth asked if the fields would be measured after the project is complete and Johnson said he did not believe so as it is typically not done.
“Is it worth the cost?” Johnson said, “No.”
Hearings on the project continue Wednesday when an expert addressing the issue of system stability and reliability will testify.
The Site Evaluation Committee is expected to make a final decision on the project in September and Eversource officials said it will take between two and three years to construct the project if the agency approves the application.
Garry Rayno can be reached at email@example.com.