Some cities are taking another look at LED lighting after AMA warning
Let&#x27;s break down their claims.<p>&gt; unseen blue light<p>I have unread negative comments about this sloppy writing.<p>They also repeatedly use the word &quot;intense&quot; incorrectly.  Intensity refers to candela.  Not lumens or temperature.<p>&gt; The original LED streetlights had temperatures of at least 4000K, which produces a bright white light with a high content of unseen blue light.<p>4000K is actually considered fairly mellow.  Above 6000K, then things start to get blue.  The earliest white LEDs were around 10000K and terrible.<p>&gt; Now, however, LEDs are available with lower kelvin ratings and roughly the same energy efficiency as those with higher ratings.<p>And now the higher kelvin lights are even more efficient.  White LEDs use phosphors to shift the blue light to longer wavelengths.  This is a lossy process.  Low-K tints require more phosphors and reduce efficiency.  That said, 4000K looks so much nicer than 6000K that the loss is worth it.<p>&gt; “As a species, we weren’t designed to see light at night,” Siminovitch said.<p>We&#x27;ve had mastery over fire for as long as we&#x27;ve been a species.  Darkness is unnatural to humans.<p>Moonlight is around 4100K.  So it is even more &quot;natural&quot; than 3000K.  Should we blot out the moon next?<p>&gt; it urged cities to minimize blue-rich outside lighting and recommended the use of LEDs no brighter than 3000K.<p>Confusing color temperature and brightness again.<p>And now from the AMA&#x27;s press release:<p>&gt; Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, [etc]<p>It seems no one has blinds in their windows.  I always carry an eye-mask with me too, just in case.<p>The AMA press release is very low on actual content so I can&#x27;t comment on most of it.  They are smart enough to avoid mentioning the &quot;blue light causes eye damage&quot; myth for example, sticking to meaningless wishy-washy statements.<p>If the people raising a fuss over LEDs actually cared, they would have been campaigning against mercury-vapor and high-intensity-discharge lamps for the past several decades.  A 4000K LED puts out way less blue light than either of those technologies.