Just fell across this story (more available by following link):

"Light pollution forms 'eco-traps'
By Mark Kinver
Science and environment reporter, BBC News

An international team of researchers has found another form of light
pollution that could have an adverse effect on wildlife.

The scientists showed that as well as direct light sources, polarised
light also triggered potentially dangerous changes in many species'
behaviour.

They added that road surfaces and glass buildings were among the main
sources of this form of light pollution."

http://news.bbc.co.uk/1/hi/sci/tech/7821298.stm

Irrespective of the merits of the story itself, it made me wonder, which
artificial lights sources produce polarised light? Incandescent?
Fluorescent? QH? LED? HID? etc. My initial thought is that incandescent,
possibly including QH, are likely to be little polarised. The question
is particularly string today as I noticed what strange effects the
lighting in various shops had.

--
Rod

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Although common it frequently goes undiagnosed.
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