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Light rail’s electromagnetic interference likely to affect some Duke equipment, report says Uni only raised concerns recently

<p>The proposed light rail would have a stop&nbsp;along Lasalle Street and&nbsp;Erwin Road near Duke Hospital.</p>

The proposed light rail would have a stop along Lasalle Street and Erwin Road near Duke Hospital.

When Duke rebutted a request to sign onto a cooperative agreement for the light rail project last week, it listed electromagnetic interference as one of the four primary concerns.

However, a report from GoTriangle says that Duke did not raise this concern until late into the planning process.

Light rail trains disrupt the area’s geomagnetic field as they operate. The shifts are mostly undetectable, but some highly sensitive medical equipment can be affected by it. The Durham-Orange Light Rail Transit (DOLRT) project’s planned route spliced Duke’s medical and research facilities, raising questions about effects it may have on medical and research equipment in the buildings near the track. 

“Since the Erwin Road corridor at Duke contains numerous patient care devices for which any deviation could be catastrophic and potentially fatal, we are not yet able to determine with confidence whether the new study we received last week can adequately address this risk,” the University's letter to GoTriangle last week stated. “If anything, the new data and our independent expert’s review of them have heightened our concerns.”

Exactly when Duke asked those questions is unclear. Durham County Commissioner Ellen Reckhow says Duke had opportunities to raise the concerns for years. 

“Yes, we were scrambling at the end to respond to the request to address this, but I would submit to you that I feel the lack of transparency and the lack of willingness to provide timely access to the information pushed us to the end of a long process needlessly, and we would have provided an analysis much earlier,” said Reckhow, who is also the chair of GoTriangle's Board of Directors.

What effects would the train’s electromagnetic interference have on Duke’s medical and research facilities? And when did Duke begin expressing concerns about this? 

The effects of EMI

GoTriangle recently produced a report about the electromagnetic interference, which Reckhow provided to The Chronicle. 

“Operation of a DC light rail system produces transient magnetic fields that perturb the static background magnetic environment—which is primarily the geomagnetic field—in proximity to the alignment,” the report explained. 

Practically, this means that the light rail’s operations disrupt the magnetic environment around it. This disruption comes from two sources—the inherent shifts caused by a large steel body moving and the currents that power the train. 

Those currents flow down from the wires above the train, through the light rail train and into the rails below. They fluctuate with the rail’s operation, so the magnetic fields they produce also vary.

Shifts inherently caused by the large steel body occur when a train is present, but the shifts that come from the electricity powering the rail system are constantly occurring and fluctuating. 

The report by GoTriangle officials offers this illustration of how the currents flow through the train cars.
The report by GoTriangle officials offers this illustration of how the currents flow through the train cars.

“The sensitivity of various instruments varies widely, so an EMI evaluation requires estimates of magnetic field transients produced by the light rail system (quantifying the source), and identification of potentially sensitive instrumentation or equipment in proximity to the alignment,” the report stated. “Comparing expected light rail magnetic field transients with the magnetic field limits of potentially sensitive equipment provides a measure of the likelihood for interference to occur.”

Several common medical machines—X-ray equipment, CT scanners and Atomic Force Microscopes—are not affected by light rails’ electromagnetic effects. Others—like electron microscopes and MRI equipment—are affected. EMI’s effects drop off sharply within hundreds of feet of the track. 

The planned route runs through Duke and ends on the campus of the University of North Carolina at Chapel Hill. The report stated that 37 facilities within 500 feet of the route containing potentially sensitive equipment were reviewed.

At UNC, the closest building to the track that was thought to have sensitive equipment was Marsico Hall, which was set back far enough from the route that “no EMI impact is expected,” according to the report. 

The Veteran’s Affairs hospital on Erwin Road was deemed to have a low likelihood of impact.

Several Duke buildings fell within the range that may be affected. 

Hock Plaza, having both MRI and magnetic resonance spectroscopy as imaging capabilities, is close enough to the track that the side of the building facing the track was considered moderately likely of being impacted, and the back of the building was labeled as having a low likelihood. 

The Lenox Baker Children’s Hospital houses an MRI machine, and the building was assigned a low likelihood for interference with the MRI. Duke Hospital North and Duke Medicine Pavilion have multiple MRI systems, according to the report. The Medicine Pavilion is not expected to be impacted, but the Duke Hospital North was given a moderate likelihood for impact.

The Global Health Research Building was given a low likelihood. The Duke Eye Center is listed as having an electron microscope, according to the report, which would give it a high likelihood of being affected because of the sensitivity of such an instrument. However, the Eye Center does not fall within the proximity to expect any MRI systems to be affected.

Additionally, the Snyderman Genome Sciences Research Building has an electron microscope, which would have a high likelihood of being affected.

Hock Plaza

In the letter to transit officials announcing that Duke would not support the light rail, University administrators listed the EMI’s effects at the top of their concerns. 

“It is clear that the DOLRT will create EMI that will interfere with current and future patient care and research devices,” the letter stated. “It is also clear that there have been inconsistencies in the information that has been generated to date, and we appreciate the continued efforts of GoTriangle to work with Duke to develop accurate, reliable data that can be evaluated by independent experts.”

The letter was signed by President Vincent Price, Chancellor for Health Affairs A. Eugene Washington and Executive Vice President Tallman Trask. 

“As you know, EMI is not a new or unique problem for urban rail systems,” the letter stated. “Indeed, similar studies done in other cities turned out to be incorrect in their estimation of negative impact on research devices.”

EMI, however, did not appear to be mentioned in a letter from Price to Durham Mayor Steve Schewel and Wendy Jacobs, chair of the Durham Board of County Commissioners, in November 2018.

The 2018 letter cited five specific points—closing Blackwell Street and access to surrounding facilities like the American Tobacco Campus, ensuring that the hospital’s trauma center is accessible for emergency vehicles constantly, minimizing disruptions caused by the construction, ensuring the electric power supply for the school and medical facilities and “ensuring the continuity and safety of research and clinical activities that take place in buildings adjacent to the planned rail line.”

When did EMI become a concern?

Reckhow said that Duke had multiple points over the course of several years at which they could have raised concerns about the EMI. Ideally, she said, University officials would have noted it in 2015 and 2016 when the Environmental Impact Study was receiving comments. 

“The thing that troubles me the most is that we had an environmental impact process to do an environmental impact statement, and all of that work was done during 2015, culminated with a robust outreach effort during 2016 and a comment period,” Reckhow said. “And if you look at that draft EIS, there are sections covering EMI, noise, vibration and some of the issues that Duke has raised over the last couple of months.” 

After the study was finalized, the rail’s alignment was largely locked into place. Now only tweaks—like elevating parts of the track or shifting its alignment in relation to roads—can be done. 

“I find it frustrating that Duke did not submit any comment during our EIS process,” the commissioner said. 

She noted that Duke may not have felt that the University needed to submit formal comments, since the stakeholders were in ongoing meetings about the rail. 

In 2017, GoTriangle officials brought up questions of the EMI and vibrations from construction with Duke administrators, Reckhow said. 

“We asked the Duke staff there to give us the list of any sensitive electronic equipment and that they give that to us along with the location of the equipment along Erwin Road. Well there was no follow-up. I understand that our staff actually sent out some email reminders,” Reckhow said. “Bottom line is we never got the information.”

Instead, she said the issue was not raised by Duke until Trask verbally noted it after the November 2018 letter. Trask did not respond to emailed questions about the timeline and his opinion on EMI Monday.

“At that time, our project manager John Tallmadge immediately said to Tallman Trask that to do the analysis we need to know the equipment and its location. We got the list of equipment about six weeks later, but not the location,” Reckhow said. “We did a preliminary short assessment with the limited information and it was not until we got the locations subsequently, could be as recently as three weeks ago, that the stats consultant did a more extensive EMI report.”

A memo published by GoTriangle about the last few months' negotiations with Duke also provides a timeline for the discussions of EMI. The memo says that on Nov. 26, six days after Price sent the letter to local officials, Trask raised the issue. 

The memo, written from Tallmadge to GoTriangle's Board of Directors, says that GoTriangle staff gave Trask the estimations of the effects on buildings and asked for the specific locations of sensitive equipment. Trask questioned the accuracy of GoTriangle's report on the EMI effects and expressed concerns about Duke having to limit where it could place new equipment in the future as a result of the light rail.

"This has been determined by Dr. Trask to be the most important remaining issue, because he is not comfortable that there is a solution," the memo stated. 

Trask provided a list of assets worth more than $50,000 and GoTriangle analysts found two electron microscopes and six MRI machines "that could be susceptible to EMI," according to the memo. 

"I have requested more detailed information about these eight devices and their specific locations from Dr. Trask, and have been told his concern is not limited to these devices, and that Duke is 'not willing to permanently compromise what patient care devices we can put in our hospital and clinics, how or where,'" Tallmadge wrote. "We have sent draft cooperative agreement language that commits to mitigating the effects of light-rail generated EMI on all future equipment, assuming that Duke makes reasonable efforts to locate EMI-sensitive equipment outside of the disturbance zones of the light rail."

Tallmadge wrote that the Maryland Transit Administration worked to mitigate the impacts of EMI on the University of Maryland's future equipment using "at-the-receptor protection." On Feb. 18, GoTriangle sent an updated analysis to Trask that did not show significantly different data than the first, Tallmadge wrote.

When asked about the timeline Reckhow outlined, Michael Schoenfeld—vice president for public affairs and government relations—said Duke has raised concerns about the route for the last two decades.

“We have been consistent and clear about indicating the concerns about this route and the potential risks and implications for patient safety,” Schoenfeld said. “We’ve done so for 20 years.” 

Xinchen Li and Kathryn Silberstein contributed to this report.

Read the full report on EMI levels below:


Bre Bradham

Bre is a senior political science major from South Carolina, and she is the current video editor, special projects editor and recruitment chair for The Chronicle. She is also an associate photography editor and an investigations editor. Previously, she was the editor-in-chief and local and national news department head. 

Twitter: @brebradham



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