Bright Lights, Big City

L.A. urbanites are accustomed to rows of man-made lights stretching endlessly in every direction. But some experts say those glittering lights in the night sky can actually change the chemistry of the air we breathe in and pose health risks.

Nearly 2/3 of all humans live under light polluted skies, as correspondent Judy Muller found. Additionally, 99 percent of all Americans never see a truly dark sky.

Dr. Ed Krupp, executive director of the Griffith Park Observatory, says city lights can get in the way of witnessing a light show in the cosmos because of the glittering landscape below. Over the years, L.A. has become a much brighter city that it used to be, says Krupp.

But light pollution does more than obscure the cosmos. Too much light can actually affect your health and air particles. In a groundbreaking study in 2010, Harald Stark from the National Oceanic and Atmospheric Administration and a group of experts were able to show that the lights of Los Angeles are in fact playing a role in air pollution.

The team concluded that L.A.'s night lights are so bright, that it's actually destroying a molecule that works to scrub pollutants in the air.