From VOA Learning English, this is the Health Report.
As astronauts circle Earth, lights from our cities make our planet shine. But these lights create a kind of orange cloud or haze that keeps us from seeing the stars.
Jim Dougherty is president of the International Dark Sky Association. He says the orange haze is light pollution. He also says too much light is bad for your health. Studies find that too much light damages our sleep, affects hormones and is linked to some cancers. Jim Dougherty says light pollution is also bad for the planet because it is causing global warming.
Mr. Dougherty went to the Capitol Hill neighborhood of Washington with VOA. He says street lights there are producing too much light. He understands that Washington city officials want to make the sidewalks safe by providing good lighting. But he says there are too many lights, and they are not designed well. They send light into the sky where it is not needed. Mr. Dougherty says that soon streetlights will not be necessary. He says better lighting for sidewalks can provide safety without wasting energy or causing light pollution.
Some communities are using new technologies that dim, or lower lights, at an exact time, like 1 a.m, when they are not really needed. Another possibility is using motion sensors. They turn lights on or off by sensing motion. Motion sensors can reduce lighting by 90 percent and still be effective. Mr. Dougherty hopes more communities use energy- saving devices like this. He says he hopes that in the future, we humans can take back the night sky.