Light pollution is the term used to describe the overabundance of light in urban areas. From cars, buildings, and street lights, it’s almost like it never gets dark in the city. And it turns out that this affects air pollution, as well.After measuring the air around the infamously polluted city of Los Angeles, scientists discovered that the extra light during the evening was actually worsening the air pollution. This is because a certain chemical–known as a nitrate radical–that breaks down air pollution, is only active at night, because it’s destroyed by light. But when it never really gets dark, the nitrate radical doesn’t have an opportunity to do its job.AdChoices广告“Our first results indicate that city lights can slow down the night-time cleansing by up to 7% and they can also increase the starting chemicals for ozone pollution the next day by up to 5%,” Harald Stark, from the US National Oceanic and Atmospheric Administration, told the BBC.One proposed solution wouldn’t see the removal of lights all together, but instead have them pointed away from the sky so as to not affect the nitrate radical.