OK... Well, I'm not going to post a multi-page wiki-rant, but let's start with this. The most common diodes are Zener, primarily used for regulating current flow, and LEDs, usually infrared, visible and ultraviolet. Not all diodes produce light. Many are painted black or encased in a black resin. Focusing more on LEDs, they're usually encased in a translucent epoxy. Traditional uses have been in the displays on electronics and remote controls, but more recently, we've seen their use in LCD TVs and computer monitors to provide more intense colors and images. LEDs use a variety of semiconductor material to produce different colors. Some are coated in phosphorus to enhance color. Intensity is controlled by voltage, "gap" and the type and amount of semiconductor material. Some LEDs contain arsenic. Some LEDs contain other toxic chemical compounds in their epoxy resin casing.
This is merely a point of semantics, but all diodes
do produce light. The fact that we can't see the light is, as you said, due to the opaque casing (or, in some instances, not visible to
us because it's infrared light), but the diode is still producing light during its normal operation.
As far as the chemicals you've mentioned, studies have shown that phosphorus is present in most LEDs currently in use for "other" purposes than indoor lighting, and arsenic is present at much higher levels in red light/laser diodes, such as those used in CD and DVD players. So, again, it doesn't appear that LED bulbs for indoor lighting are significantly different from the thousands of LEDs contained in other devices, at least not in their usage of chemicals.
Of course, the studies that have shown the existence of these chemicals in current LEDs also indicated that there is no immediate health hazard upon the breaking of the bulb. Rather, they were only able to produce somewhat hazardous results by simulating acid rain in landfill conditions to produce a “worst case scenario.†Additionally, they did so with colored LED bulbs included in the test, which are known to have higher arsenic levels than LEDs which emit white light or other colors of light.
This corresponds with what I've said so far: Current LEDs and these "new" LED light bulbs are not as drastically different as was initially claimed. Chemicals used in the production of these items have been present in electronics for decades. Does this mean that no other studies should be done on them? No, but why would we give the stamp of approval to LEDs with arsenic in DVD players, but not LED light bulbs? Why say that it's okay to use arsenic in wood preservation products and rat poison, and phosphor in pesticides and industrial waste, but not LED light bulbs? I don't understand why someone would be completely happy with their arsenic-laden DVD player, and would see no reason to ban the sale/use of these DVD players until further studies are done, but adamantly oppose the sale of an item with the same chemicals until further studies are done.
We don't know, and you're just speculating. Your assumption above is that all LEDs are created equal.
It's not that they are created equal; it's that they are more similar than they are dissimilar. Arsenic has been found in these new LED light bulbs. Okay, well, arsenic is also in LEDs not used for indoor lighting purposes, including higher levels of arsenic in LEDs that are in vehicle taillights and DVD players. Phosphor has been found in these new LED light bulbs. Well, phosphor is also contained in virtually all other LEDs.
If there's a hazard present due to the inclusion of these chemicals, then we need to rethink
all LEDs, not just those that are being introduced to the market. My point is that we shouldn't act as if these chemicals are just now being introduced to the market and exposed to humans due to the invention of a "new" type of LED; these chemicals have been used in a variety of products for quite some time, including in some products in which our exposure is much greater.
We're speculating that the light produced will fall within a spectrum that is similar to incandescent lighting, but we thought the same of CFLs too. We later found that the spectrum is slightly different and can cause headaches and other issues. Working 8 hours a day in front of a computer, people frequently complain about LCD monitors causing eye stress and headaches. We don't know if this same issue will continue or even be worse with LED lighting. Again, we just don't know.
A) Those people with headaches are pussies, B) we have devices that can detect and record spectra, so I'm not sure why we'd have to guess where in the spectrum LED light would fall.
By the way, LCD monitors don't use LED as a source of backlighting. Well, they
can, but if they are advertised as an "LCD monitor," then they use a fluorescent backlight. An LCD monitor that has LED backlighting will be advertised as an "LED monitor" or "LCD-LED monitor." Given the fact that LCD-LED monitors are still not that popular (but are more popular for televisions), and given the fact that the initial LCD monitors up until the last few years were backlit by fluorescent lights, I would assume that these headaches are due to fluorescent lighting, not LED lighting.
Do you really think that the use of incandescent lighting could ever be a significant burden or drain on the government? Really???
I'd call $15 billion wasted annually a financial burden, especially considering that the incandescent bulbs that we are powering are using 80% of their energy consumption on producing heat, not light.