Climate change has fed awareness of air pollution – the problems caused by greenhouse gases, but there’s another source of pollution that’s taking a toll on humans and wildlife.

A professor at the University of Virginia is calling on local, state and national leaders to act against light pollution.

Sandy Hausman reports

The Fan Mountain observatory sits at the end of a steep, one-lane road in rural Nelson County. UVA Professor Kelsey Johnson and her colleague Whitney Richardson make the trip on a regular basis so they can study the stars through a 40-inch telescope.

As the dome opens, Johnson laments the loss of visibility, because the city -- about 20 miles north on Route 29 – keeps growing.

“That’s Charlottesville out there in the distance," she says. "It’s not like Charlottesville is even a major metropolitan area, but it still illuminates that whole part of the sky, and we’re not even away from that here. All the cars down there, that’s 29. That’s everybody going home from work.”

She knows night-time lighting is needed to keep people safe, but in this country much of the light we pay for is wasted.

“The cost of the light that goes out to the sky and out to the universe, that doesn’t do us any good is about $3 billion a year,” she explains.

And light pollution has taken a toll on star gazers around the world. In 1994, when an earthquake knocked out power in Los Angeles, people actually called local emergency centers to report seeing a “giant, silvery cloud” in the night sky. What they saw – usually invisible because of city lights -- was the Milky Way.

“I worry that we are losing things that give us a sense of awe -- seeing something that just smacks you and blows you away. I don’t how you measure it. I don’t know what the impact is, but I feel like it’s really important to being human.”

The excess light is harmful to human health.

“There’s a very clear link, for example, between an increased exposure to light at night and an increased risk of breast cancer. It’s about 50%. It’s linked to obesity, anxiety, depression, cardiovascular disease. Across the board, light pollution is really pretty bad for us.”

And it’s disturbing to other animals.

“Critters on earth have evolved now to having a day/night cycle, and all of the plants get screwed up from light pollution.”

The solution, Whitney Richardson says, is to change the way we light.

“People put in these big street lights. They’re like, ‘I’m going to light up everything!’ Because they’re throwing all that light up in the air, it’s not going where it needs to go, which is on the ground. So if you’ve ever flown into Tucson, Arizona, they have very strict lighting laws there, because of the telescopes nearby, and when you fly in it’s really cool, because all you see is the ground. You don’t see these little sparks of light -- the street lights. You see the ground.”

And the best urban planners choose warm lights – those with a rating of 3,000 kelvin or less.

“The lightbulbs that say ‘blue’ or ‘daylight,’ those are meant to mimic daylight, and those are terrible both for sky pollution and for your health. It’s that blue light, when it hits your retina at the back of your eye at night that really causes the health problems.”

Virginia has just started modernizing its highways -- replacing 96-hundred lights with LED bulbs. That will cut energy consumption in half and, officials say, improve visibility for drivers while minimizing light pollution.

To keep the country moving in this new direction, Johnson recently gave a Ted Talk at the National Academy of Sciences and has started a star-gazing program for children in Virginia schools called Dark Skies, Bright Kids.

***Editor's Note: The University of Virginia is a financial supporter of Radio IQ.