2012 article

Camille M. Carlisle

Researchers are raising several possible health concerns related to nighttime light exposure, among them a higher risk of cancer.

I usually think of light pollution as astronomers’ concern. Who else would mind if the sky glow is so bright that it washes out Orion? (When I can’t see Orion, I feel jilted — yes, even in the months when it’s below the horizon at night.) But the issue has a broader reach than my petulance. Fighting light pollution isn’t merely about seeing stars; it’s about being sensible in our usage and reducing waste.
The document’s first human concern is glare, which report coauthor Dr. Mario Motta (Tufts Medical School) outlined for S&T readers back in 2009. Glare’s a pretty standard discussion topic in light-pollution conversations, in part because, as drivers age, their eyes become less able to cope with poorly directed light that scatters inside the eye itself. In 2009 the AMA passed a resolution submitted by Motta supporting the use of fully shielded lights, such as the flat-bottomed street lights. The new report reaffirms that resolution.Still, I was surprised to see that the American Medical Association recently released a report entitled “Light Pollution: Adverse Health Effects of Nighttime Lighting.” It’s a review of some of the available research literature on nighttime lighting’s effect on people; it doesn’t present new research done by the AMA, although many of the results considered come from the authors‘ own work. The report covers a lot of ground, but it’s unclear what the review’s effect will ultimately be.

Vision researcher Gary Rubin (University College London) agrees with the report’s concern, saying the conclusions are “balanced, well-reasoned and thoroughly researched.” Disability glare — as opposed to “discomfort glare,” which differs from person to person — is definitely a problem for drivers, he says, noting that some cataract patients have had second surgeries to replace their new intraocular lenses with another kind that causes less nighttime glare. And as many of us know from experience, modern halogen and LED headlamps can make nighttime driving downright painful. (I can’t tell you how many times I’ve looked away from an oncoming car’s bright bluish headlights and thought, with scathing condescension, “Is that really necessary?”) Blue-rich light’s destructive effect on the molecule rhodopsin (a.k.a. “visual purple”) in the retina is what makes these headlights hurt so much.
The entire article can be found at this link.