Re: what is the limit of light pollution?

i've read about light pollution and i want to know at what point it is considered a kind of pollution. is it that any form of light is considered pollution and pollution does not neccesarily have a negative impact? tell me more about the definitions of pollution.
if possible, tell me why the heart beats faster and people can have high blood pressure due to noise pollution?

1. To make unfit for or harmful to living things, especially by the addition of waste matter. CONTAMINATE.
2. To make less suitable for an activity, especially by the introduction of unwanted factors: The stadium lights polluted the sky around the observatory.

The American Heritage® Dictionary of the English Language, Third Edition copyright © 1992 by Houghton Mifflin Company.

Pollution always has a negative impact; it just depends on whose ox is being gored (a wonderful English metaphor meaning "Who is the winner? and who is the loser?"). Light pollution is one of the best examples of one person's detriment being another person's benefit.

Noise pollution results in a more-or-less constant background of unwanted loud (and often sudden or sharp) noises, and is a feature of large cities, of factories, and of other places where there is a lot of machinery running. Since humans (like most animals) have the ability to be startled by sudden noises, it's not surprising that the heart beats faster and blood pressure goes up due to noise pollution. Such things prepare the body for "fight or flight."