See how many street lamps allow plenty of light to shine upwards. While some people have dismissed light pollution as simply a problem for a small minority of people who are astronomers or who have an interest in the night sky, Smith said that such pollution has a greater environmental impact. Reported adverse effects of this fog of artificial light involve plants and animals as well as humankind. Light pollution concerns are not limited to visible wavelengths of light alone. Radio astronomers have expressed growing concern about the interference signals from radars, television and radio broadcasts, and even mobile phones, pose to their work.
Satellite transmissions are also a problem to radio astronomy.
Transmissions from Global Position System satellites can trigger false alarms for SETI programs, and the threat of powerful transmissions from the now-defunct Iridium constellation of communications satellites required radio astronomers to work out special agreements with the company to reduce the power of satellite transmissions at some times. Because of these problems, astronomers at the IAU meeting said they are working with regulatory agencies to preserve some radio wavelengths for astronomy work, as was accomplished in June, when the International Telecommunication Union set aside a range of frequencies for use in astronomy rather than telecommunications work. The problem of light pollution in densely-populated, industrialized regions such as Europe is illustrated in this satellite image.