Light pollution may be a more serious concern than you think. New evidence suggests that a lack of darkness in our urban night skies contributes to air pollution, making it a matter of public health. Yet Los Angeles keeps rolling out bigger, brighter signs. Correspondent Judy Muller investigates.
Judy Muller/Reporter: Los Angeles, where the bright lights of the big city spill out over the terrain, stretching endlessly in every direction. For the first time in the planet's history, more people are living in urban areas than in the countryside. And this urban area says it with light. Incandescent, halogen, L-E-D, fluorescent -- our environment is dotted with examples of how man has conquered the dark.
Dr. Ed Krupp/Griffith Park Observatory: Certainly Los Angeles, in many respects, is a much brighter city than it used to be, and for an astronomer that is an irritant because you like to see the night sky.
Muller: Dr. Ed Krupp is the executive director of the Griffith Park observatory. He says it's tough for city dwellers to witness the light show in the heavens above because of the glittering landscape below.
Dr. Krupp: The light that goes up into the sky is scattered by the air molecules and brightens up the entire background which is why faint the stars disappear.
Muller: Take a drive around the city at night and you’ll see those million points of light.
Dr. Krupp: There are many places where you see very large new buildings illuminated as columns of light, sometimes with spotlights, sometimes with all kinds of other paraphernalia. And those of course add to the complication.
Muller: A recent study showed that nearly two-thirds of all humans live under light-polluted skies. 99 percent of all Americans never see a truly dark sky.
Dr. Krupp: It's a heartbreaker that we are not as focused on the sky as we once were.
Wally Pacholka/Photographer: To see the Orion rising over Monument Valley or the Milky Way rising or setting over Capital Reef National Park, there is nothing quite like being there and experiencing it.
Muller: Wally Pacholka knows what urbanites are missing. He travels the world taking pictures of the night skies. He's one of the best astrophotographers in the world, winning TIME magazine's Picture of The Year three times. His photos are so beautiful, many wonder if they've been altered in some way.
Pacholka: Their initial reaction will be “Boy, I never thought that you could see skies like that.” They think these photos must be computer generated or something, when in fact these are real actual photographs. For folk that think they are not real, I encourage them to go out to a dark location and see for themselves.
Muller: That might be good advice for these people we met recently at the Griffith Park Observatory. They were having a hard time seeing some of the 2500 stars that would be visible in a dark sky.
Observer: I haven't seen the Milky Way in L.A. like I did in Texas.
Observer2: You don't see stars in L.A., at least you don't think to look up because you assume they won't be shown.
Dr. Krupp: Out of the potential of perhaps 2000 - 2500 stars tonight in Los Angeles, if you go downtown, I don't think you'll see one.
Muller: Light pollution does more than obscure the cosmos. Some L.A. residents complain about visual blight. While providing protection from the dark, blinding lights are saturating homes and buildings. And now there is new evidence, scientific evidence, that too much light affects your health.
Harald Stark/NOAA: The effect is there, and we know we can measure it.
Muller: National Oceanic Atmospheric Administration Scientist Harald Stark and his team were in Los Angeles last year conducting a study on how sunlight affects air pollution. The team made several daytime flights over the city, collecting air samples.
Towards the end of the research, a colleague suggested Stark do a night flight. Why? To see if L.A. was so bright at night, it could actually affect air particles the way the sun does. Stark had his doubts.
Stark: I was not too excited about these night flight for my instruments originally, because I thought, “Well it will be dark. Maybe I can just sleep.”
Muller: You didn't think you'd find anything?
Stark: I didn't think I would find anything.
Muller: But he did. The data from those night flights resulted in a groundbreaking study showing the lights of Los Angeles are changing the chemistry in the air we breathe, and not in a good way.
Stark: It turns out there is one molecule out there that is actually sensitive, so sensitive to the light that it is not even there during the day.
Muller: And why is this molecule so important and what do you call this molecule?
Stark: It's called the Nitrate Radical. It serves as a cleansing agent for other molecules at night.
Muller: That's right, a molecule that works the night shift. It's one in a million, millions actually, but it exists only in darkness. Like a vampire, it is destroyed by light. But unlike a vampire, the Nitrate Radical is a force for good; it scrubs pollutants like ozone from the air. It is, in fact, nature's version of Mr. Clean. But stark's study found it's not just sunshine that kills the Nitrate Radical. L.A.’s night lights are so bright, they are destroying parts of the molecule, interfering with its cleaning job, which means that the next day the smog is worse, possibly as much as 5 percent worse every day.
Stark: You have to keep in mind many cities are often close to their limits in terms of ozone exposure. So, even a few percentages may push it above or below some kind of regulatory limit that has been set.
Muller: So light pollution can equal air pollution?
Stark: Yes light pollution can contribute to air pollution.
Muller: Stark presented his findings at a conference in San Francisco last December. While his research must still go through the process of peer review, his study has put him in the public spotlight.
Muller: So all over the world you've had reaction to this groundbreaking study. So I’m going to assume since you did this study over Los Angeles, you must have heard from L.A.?
Stark: I have not.
Muller: You might think a study that shows light pollution causes air pollution would be part of public policy in a city that has more billboards and smog than any other place in America. You would be wrong.
L.A. Councilmember Dennis Zine: This is the first I’ve heard of it.
L.A. Councilmember Bernard Parks: I don't think many people have given that much thought.
L.A. Councilmember Jan Perry: Not until you called, I had not heard of him.
Muller: In March, when the city council voted to approve 30,000 square feet of digital boards on twin skyscrapers to be built in Downtown, known as the Wilshire Grand Project, there was no mention of light pollution or the energy it takes to power those lights.
Jan Perry: Signage is an important part of Downtown's architectural context and contributes to the city's skyline.
Muller: Councilmember Jan Perry championed the project's digital displays.
Muller: But if it were shown with this new science from NOAA that it could increase air pollution by as much as 5 percent, would it change your mind?
Perry: Well, I don’t' know. I’d have to see the analysis on this. I do sit on the board of the South Coast Air Quality Management District, and I’d be very interested to see what they had to say about it and what their analysis is.
Barbara Broide/Activist: I didn’t' feel that the tough questions were being asked from a policy perspective.
Muller: Community activist Barbara Broide was one of a handful of citizens who raised the environmental concerns about the Wilshire Grand Project.
Broide: What about energy consumption? We want to be a green city. L.A. is supposed to be a green city, and yet we are permitting digital displays and lights from ground to roofs.
Parks: everyone leaves la live and says, “This is a beautiful addition to L.A. Look at the revenue that’s coming in. Look at the type of employment. Then you find out that, because of the signage, you may be creating another dynamic.
Dr. Krupp: In an era of energy conservation and era of loss of the glory of the night sky, I think it would be very prudent to wonder how any decision that we make, with respect to electric illumination, impacts the rest of the things we care about.
Muller: Putting public policy aside, photographer Wally Pacholka believes there is something more fundamental about protecting the night sky.
Pacholka: It gives kids the idea that their world is not just the street they live on. It's a world worth their exploring. And when you get their interest in something beyond just themselves, they could actually discover themselves more.
Muller: And, with any luck, discover the healing power of darkness. I'm Judy Muller, for SoCal Connected.