PORTLAND — A citizens group is appealing a decision by the Maine Public Utilities Commission on “smart meters” to the Maine Supreme Judicial Court.

The Maine Coalition to Stop Smart Meters believes the PUC’s decision does not do enough to protect the public’s health and safety. It wants the high court to roll back installation of smart meters, or at least strip the costs of opting out of the meters.

Last year, the PUC heard arguments from the coalition and Central Maine Power Co. on the safety of the electric meters. The PUC had initially dismissed a complaint alleging health risks associated with the technology, brought by coalition leader Ed Friedman, but was ordered by the state supreme court to reopen the complaint to investigate the safety of CMP’s meters.

In December 2014, after hearing from both parties, the commission ruled that smart meters “(do) not present a credible threat to the health and safety of CMP’s customers.”

Friedman and 16 other members of the coalition have appealed that decision to the the state’s highest court.

At issue is a debate over the safety of radiofrequency radiation emitted by the meters, and claims that RF radiation can cause everything from nausea to cancer.

In 2009, CMP received $96 million as part of the federal stimulus act to install advanced metering in its service area.

Smart meters record home electricity usage at intervals throughout the day and send that data remotely back to the central system. Unlike traditional meters, smart meters allow two-way communication between the meter and utility.

“Smart meters give a much more detailed picture of energy use,” CMP spokeswoman Gail Rice said. “They allow for more precise information on when the load on the grid is greatest and allows the utility to optimize its needs better.”

She also said customers can download their own usage data to figure out ways to lower their electricity use and utility bills.

CMP has installed more than 610,000 smart meters – covering nearly all of its customers – in the western half of the state.

But activists point to a body of scientific research questioning the safety of RF radiation.

Just one day before the appellants filed their brief with the court, a group of 190 scientists wrote a letter to the United Nations and World Health Organization calling for better public protection from electromagnetic field exposure.

“Based upon peer-reviewed, published research, we have serious concerns regarding the ubiquitous and increasing exposure to (electromagnetic fields) generated by electric and wireless devices,” the letter states. “These include … radiofrequency radiation emitting devices, such as cellular and cordless phones and their base stations, Wi-Fi, broadcast antennas, (and) smart meters.”

The complainants find grounds for their claim in the nature of what they call a “very unusual” decision by the PUC.

They cite that in the 31-page opinion written by Commissioner David Littell, the commission does acknowledge a health risk from RF emitted by smart meters.

“If limited RF… exposure is recommended by a doctor or medical practitioners, I would address the pending complaint by allowing for a … meter in a no transmit mode or turned off at the ratepayer’s primary residence at no cost,” the opinion states.

That opinion is not reflected in the PUC’s final ruling of no threat to health and safety. Complainants believe this means the commission has not ensured safety for all ratepayers, “as is their statutory mandate,” they said in a press release.

“A PUC opinion can be vacated when it is unreasonable, unjust, or unlawful in light of the record,” Friedman added Monday.

The PUC’s final decision reflected negotiation between Littell and Commissioner Mark Vannoy, because former Chairman Tom Welch recused himself from the proceeding based on his prior employment with CMP.

“We had two different opinions,” Littell said in an interview Thursday. “We both agreed (the meters) were safe, but had different approaches on how to approach safety.”

Littell wrote that the studies by the World Health Organization that find cancer risk associated with RF radiation emitted by personal devices focus on cell phones and cordless phones, and that exposure to radiation from smart meters is “markedly less.”

But he believed CMP should turn meters off on request as part of the “safety determination” process.

It currently costs $40 to opt-out of the smart meter program, and then $12 a month to maintain utility service.

Littell added he believes his opinion was “the best resolution of case for ratepayers, public, and the utility.”

With the appeal approaching, CMP’s Rice said “we are simply waiting to see what happens next … we feel the resolution and opt-out fees are fair.”

“There is very little consistent scientific evidence showing harm,” she added.

Friedman called the RF radiation from devices like smart meters and cell phones “the biggest toxic threat of our time.”

“We need to be using the precautionary principle,” said Kathleen McGee, another appellant in the case. “We don’t need to prove causation when looking at a strong correlation.”

“We know enough given the thousands of studies that show this link,” Friedman added. “The (PUC) failed to fulfill its legislative mandate to assure safety.”

The PUC has until June 30 to file its response.