LEDs Make Light Pollution Worse—But What’s the Solution?


Environment-destroying pollution tends to evoke a sea otter covered in crude oil. While that image is none too pleasant, light pollution tends to get taken less seriously because, well, what’s so bad about some light?

“Light pollution is excessive, misdirected, or obtrusive artificial (usually outdoor) light.” source: The Globe at Night

It turns out a lot can be wrong with too much, too bright city light. Like an increased risk of breast cancer (light after dusk interferes with melatonin production, which has strong anti-cancer properties, according to the Harvard study), disrupted sleep patterns and lost migratory birds. It turns out that certain types of light are particularly disruptive, which most of us are familiar with. Blue light, the shortest wave on the light spectrum signals to the brain that it’s rise n’ shine time. And that also happens to abundant in LEDs, the wunderkind light that burns bright and strong with maximum efficiency.

Last summer, we wrote about why the new ‘smart lights’ in Chicago might not be so smart after all. Now with a study linking breast cancer to excessive blue light, the issue becomes really becomes something to lose sleep over. This is significant because breast cancer has, according to that same Harvard study, eluded a direct causative agent, unlike many other cancers. As mentioned before, exposure to blue light can suppress melatonin production. According to the American Medical Association, it can have a fivefold effect on reducing melatonin secretion by the pineal gland, a chemical which plays a role in preventing cellular oxidation. This is the same light in those mega-bright streetlights—the kind that city dwellers are sure to be exposed to for multiple hours, cumulatively, each year.

Like many environmental issues, couching issues in quantitative data is often more effective than simply debating the intrinsic value of a dark night sky, which can include a sense of belonging, connection, and wonder to share with family and friends.

We have a classic technology conundrum on our hands. Whereby evolving technology has made so much possible (24-hour ramen shops anyone? Perhaps more crucially—emergency rooms, fire stations etc), but now poses a direct risk to our health, and the health of our environment.

According to the International Dark Sky Association (IDA), the effects of light pollution on animals can be devastating. Not only can it throw off migratory birds, it can also detour baby sea turtles away from the ocean to that bright baseball stadium in the distance. This might make you feel angry because sea turtles are so majestic, and the struggle of the hatchlings to the ocean is the source of much awe (this video has over 7 million views!) Additionally, as IDA points out, prey use dark to hide, and predators use to conceal themselves during a hunt. Certain animals have nightly calls and other rituals that play key roles in their mating seasons. Damage this and animal populations will take a big hit over time.

In our last article, we talked about why bright and more abundant light might not actually make it easier to see (or avoid being seen and targeted). Essentially, the brightness can cause pupils to constrict, creating momentary blindness as pupils adjust to spaces between street lights. This doesn’t mean that we think no street lights are necessary. On the contrary! Increased lighting definitely helps people feel safer on their commutes. But there must be a less destructive way of lighting our (growing) cities. A way of helping our environment, the people in it and the animals we coexist with. And of course, a way to reduce preventable disease and carbon emissions.

We can invest in warmer temperature LEDs, which don’t disrupt melatonin production as much, or we can make them motion activated/and/or downward facing. However, for personal reasons, I can see why the motion activated lights might not be the most popular—they still leave large swaths of areas totally dark until you come into contact with them, potentially causing unease. Rather, I think the downward directed and warmer temperature lights (though still made of higher efficiency LEDs) are the more effective solution both for a sense of safety and visibility, and to utilize the incredible efficiency of LEDs.

Streetlights are there for cars, but they are also there for pedestrians trying to navigate their environment after the cover of darkness. Designing with cars in mind, from a safety perspective, simply isn’t fair. It erases sidewalks and streetside businesses, making a trip home feel all the more tremulous.

Look, no one is saying that conditions are more or less safe when there are lights on. But being able to see and vet your surroundings is a key part of feeling more in control of your environment and designing safer cities. Is there another solution besides lighting up the night? Yes, and no—and design plays a crucial role. Considering safety and visibility can and should be a key part of overall urban design strategy, especially when considering populations who experience higher levels of violence and assault.  

In a survey conducted in three London neighborhoods by Making Places Safer, several factors were identified in public spaces that felt safe for women, including good lighting, clear site lines (lack of obstructive shrubbery) and clearly marked spaces for pedestrians to go.

A quick laundry list of places that one might feel unsafe walking home after dark: bridges, underpasses, alleys, parking lots, and of course, those weird, shrub-lined barely-there sidewalks in places that rely heavily on cars as a primary mode of transportation.

Remember Jane Jacob’s Eyes on the Street? In it, she says that people like to be able to see clear through a park/parking lot in order to feel at ease whilst in it. Can we design away underpasses, and parts of the city where the sidewalk cuts off, leaving you to traipse home in the shadows? Can we program our lights to be self-fixing, so that, too bright or not, we aren’t leaving entire blocks in the dark? Taking it a step further—what makes people congregate in public spaces, which people also point to as a factor in their general sense of safety. Can we make sure our cities are walkable, public transport is accessible, comfortable, safe and efficient, and we are doing everything we possibly can to build a city that feels safe, open and navigable—for everyone? If we are to reduce individual car transportation while boosting bike and pedestrian traffic, surely our aims to increase a general sense of safety overlap with our overall environmental goals.

In conclusion, 24-hour lights have brought us many benefits, including an increased sense of safety, and goods and services that are there when you need them. But they also have many negative effects, and the recent link to carcinogenic risk makes these even harder to ignore. What do you think? How do we address light pollution, energy efficiency and public safety in a modern society?