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Fueling Rational Discourse on Blue-Light Hazard

Fueling Rational Discourse on Blue-Light Hazard


By Jean Whatley

The gap has widened in recent weeks between researchers in the lighting industry and some in the medical community over potential blue-light hazard from LED lights. Results from a study authored by the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute were published in the International Journal of Occupational Safety and Ergonomics  (JOSE) in early October in an article, “Evaluating the Blue-Light Hazard from Solid State Lighting” which roundly discredited one aspect of a report by the American Medical Association (AMA) that LED lights pose more of a blue-light hazard than other forms of lighting.

The AMA position, which the LRC has now debunked, centers on using correlated color temperature (CCT) of a given LED light source as a gage for predicting retinal damage. The LRC study asserts that it’s more important to measure the spectral radiance characteristics of a given light source to accurately assess its blue-light hazard potential. In the abstract derived from that quantitative research, which looked at incandescent, fluorescent, LEDs and daylight sources, the LRC reported that in the majority of cases, LEDs do not exhibit greater risk for blue-light hazard than other sources because they “generally produce little to no ultraviolet energy” and a person’s “photophobic response (blinking or looking away) limits exposure to bright sources.” The study did urge caution in cases where photophobic responses might not occur, such as in eye surgery patients or premature infants, even stage actors who are trained to resist the urge to blink or squint. This new study is a follow up to the LRC’s initial response to the AMA report in 2016, which was published shortly after it first appeared.

LightED interviewed Mark Rea, Ph.D., one of the members of the LRC research team, to learn more about the impetus for the study, the researchers’ reaction to what they discovered and what’s next in amplifying their findings to help close the knowledge gap.

Q. Fundamentally, why did you engage in this research?

A. My research colleague, Dr. John Bullough had written a report back in 2000, but people tend to think, not in terms of basic principles, but rather technology. So there really hadn’t been anything written specifically about LEDs. That’s why we wanted to update it and make it more accessible, I guess in terms of every day language, like “don’t look at it [LED] for more than thirty minutes.” I think people can understand that a lot better than going through the calculations directly. Part of our research, as much as anything, was really part of a technology transfer focus on the blue-light hazard, bringing things together, trying to put it into a cohesive story that I think would have broader consumption than just the three or four experts in photobiology that are out there. I just felt there was a large gap and probably the AMA report reflects that gap, in really understanding the basics. So our job, as we saw it, was to make that translation, such as making the comparison that a bare incandescent lamp at 2800K is more dangerous than any LED light you have, and correlated color temperature just isn’t the way you want to talk about blue-light hazard.

Q. Were you and your colleagues surprised by the findings?

A. No, not at all. It’s pretty well known stuff. That was the disappointing thing about the AMA report, the action of a high radiance source is very well known. So it was surprising to us that an organization like the AMA wouldn’t be more responsible by checking the conventional literature that was already out there. Having said that, I have to admit the literature is a bit arcane. What we tried to do with our study was to try to translate the information down to something people could grasp. For example, “if I stare at this light for thirty minutes what happens?” That doesn’t come directly out of the literature. So we felt it might be helpful to try to give people insight into its cause as well a sense of risk.  Also to remind people that generally these studies are based upon anesthetized monkeys, with their retinas directly exposed to light. So they don’t have the averting photophobic response that seems to be forgotten sometimes. People don’t like to look directly at bright lights.

Q. How do you think people should react to the AMA report?

A. When people are not informed, they turn to professionals. I mean, that’s what we do with physicians. We go to our physician. They prescribe a treatment protocol or pharmaceuticals and we take it for granted that that’s the right thing for us. We seem to defer what we believe to people who set themselves up as experts and I think that’s the real disservice that the AMA did. As you dig a little deeper, there was one person who was involved who was an advocate for dark sky and really sort of put this thing together and because the AMA didn’t fully understand it, they just went ahead and approved it. In my opinion, they have a responsibility, because they are seen as experts certainly more than lighting people, to say what really is state-of-the-art, what is the current and relevant data. To counteract what’s been incorrect, but authoritative statements, it will take education by many small steps, multiple articles across a wide spectrum of publications, to help give people the information they need to make informed decisions. Our recent paper is one small step.

Q. How do you think a more factual and robust conversation can occur, between the lighting industry and the health sector to benefit consumers who just want to know what’s safe?

A. I do think it’s going to have to be a steady discussion with multiple people, agencies, publications and platforms, all working toward a common purpose. Unfortunately, going all the way back to the first energy crisis in the 70s, the lighting industry generally had a bad reputation, sometimes justified, sometimes not. So if people from the industry push back against the AMA, I think the average consumer is more likely to believe the AMA. Working together is a better strategy. Forming alliances with reputable agencies, like the National Institute for Occupational Safety and Health, the National Institutes of Health or the Centers for Disease Control, would go a long way in trying to combat the bad information the AMA put out. I doubt very seriously they will ever publish again on this topic. I think they realize they made a mistake. Forming alliances for research or public forums between the lighting industry and health organizations would make the outcomes of these joint investigations or co-hosted events more credible and, importantly, correct. In the end, belief is a social thing. People don’t read much. People get introduced to these sorts of topics through the kinds of venues where people are sharing ideas in a public forum. It works well.

Learn More

To read the entire study entitled “Evaluating the Blue-Light Hazard from Solid State Lighting,” click here.

To read the 2016 LRC’s response to the AMA report go to: http://www.lrc.rpi.edu/resources/newsroom/AMA.pdf.


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