What is light pollution?
December 16, 2008
Light pollution can be amplified by air pollution as dust and smoke scatter skybound radiation in all directions, further brightening the sky. Both kinds of pollution are environmental problems that affect not only astronomy, but animal life and human health as well.
Astronomers can avoid light pollution by traveling to dark-sky locations far away from cities (the source of most light and air pollution). To a limited extent, eyepiece and camera filters can be used to counteract light pollution.
See here: How does light pollution affect views through my telescope?