"When we switch from a sodium lamp to a white LED, what we observe is a decrease in the total amount of light that the satellite can see.
But what we saw instead for the US was basically a constant amount of light; new lights were added in other places,"

Last year, the American Medical Association issued an official policy statement about LED street lighting, recommending a radiance and color temperature level less harmful to health.

Another landmark study published last year found that 83% of the world's population and more than 99% of the US and European populations were affected by light pollution and could not see the stars at night.
Studies weblinked in article:
Artificially lit surface of Earth at night increasing in radiance and extent

The new world atlas of artificial night sky brightness

AMA Policy weblinked in article: