Other than astronomers, people rarely think about light pollution. In fact there are a variety of negative health effects around disruption of circadian rhythm and a range of effects on our wildlife. You can read about some of these effects at the website of the International Dark-Sky Association (IDSA). Most of the world's population never sees a truly dark sky, yet this is a situation that has only been in place for the last hundred years or so. Having lived in rural Australia, where the Milky Way stretches from horizon to horizon and Western Europe, where there is nowhere with a truly dark sky, I know from experience the difference. Even here in Adelaide I can only see a fraction of the sky that I could see in rural Australia. Well the journal 'Science' has published the latest map of 'artificial sky brightness' and it is open access, so you can see how your region or country fares here. What is important is that our local councils use appropriate lighting. See the IDSA website for details.