Cool White Lighting & Circadian Rhythm

In some ways LEDs help, and in some they may harm.
Timing Example - Before the ′50s our United States experienced atmospheric LEAD poisoning.
It was defended by Auto and Petrol suppliers against Geochemist Clair Patterson, PhD. 
After 20 years, Government took his advice.
- - Now - -
This relates our environment and the 450nm emission of white light.  This is more than lighting.
See this Melatonin lab test by Mark S. Rea, PhD  and see the Circadian Effects caused by these LED types
This cool-white LED reduces melatonin twice as much as reduced by this warm-white LED.
Why? Intrinsically-Photosensitive Retinal Ganglion Cells (ipRGCs)  respond to LED′s blue light spike.
These cool-white LEDs have 2× 450nm as their 500-700nm, a color ratio exceeding natural light.
These white LEDs show 450nm blue emission less than half their 500-700nm emissions.
Atmosphere protects us from full spectrum.  We need awareness of ′blue per Lux′ with all lighting.

If you′re in cool-white lighting near bedtime, then estimate a sleep aid supplement for proper rest.
AMA    Nocturnal Melatonin Suppression = endocrine disruptor linked to diabetes, obesity and cancer  
Fluorescent lighting has done this for decades, and LEDs could prevent this problem if desired.
Health issues are rising every year: we are not sleeping well & we need more sleeping aids.
How long did it take to get health warnings on cigarettes, or on gasoline pumps?
Answer: 20+ years

We will see warning labels for cool-white LEDs.
How Electric Light Is Harming Normal Sleep Cycles      Melatonin Effectiveness     Natural Daylight or LEDs?
NIHPA 2010: Effect of Light on Human Circadian Physiology         Future of LED lighting
Radford University Paper with Dr Patterson, page 9 (392)that PDF file
See that Melatonin Lowers Breast Cancer Risk
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