Environmentalists have pushed to abolish traditional incandescent light bulbs, in order to reduce the amount of electricity needed to light up our homes.
However, a small but vocal minority has insisted that the curlicue-shaped compact fluorescent light bulbs (CFLs) pose a threat to human health.
Now, a group of scientists at Stony Brook University has proven that CFLs do emit ultraviolet (UV) light rays that can harm human skin cells.
Cracks in CFL coating
In the first part of their study, the researchers purchased CFLs from different stores in two different counties. Then they measured the invisible UV rays given off by the bulbs when lit.
The rays appeared to escape through tiny cracks in the white phosphor coating on the inside of each CFL bulb’s glass. The phosphor particles actually glow with visible light as a result of an electrochemical reaction inside the bulb.
The scientists noted that these cracks in the phosphor were present in all the CFLs they studied. They found significant levels of UV were emitted from the bulbs.
The dose makes the poison people. How much UV are we talking about here? Although I’m no fan of CFLs, I’m guessing that the actual exposure levels are miniscule.
Apparently enough that it can be a problem and not just for people especially sensitive to UV light – examples that came up previously are a mechanic that got sunburned working in a maintenance pit after the work lights were changed to CFLs and several cases of reading/desk lamps giving users inadvertent excessive indoor “tans” (IIRC it involved UV-burned ears & face and an office worker with one forearm & hand burned under the desk lamp).
Also, Several studies before Stony Brook (EU, UK, Canada) all with same
results
More on that and the Stony Brook research itself, with spectral diagrams and UV information via that Tonn.ie site linked below (frontpage story)
Those double envelope CFLs they recommend also means reducing their light output still more
There is more irony about the CFLs, eg leave them on, waste energy, switch them on-off, shorten their life,..
Basically, bulbs are the wrong way to use fluorescent lighting
technology, best in long tube form,
just like LEDs have natural lighting advantages in sheet form.
CFL/LED natural advantages are largely compromised in offering
politically pushed incandescent-copying lighting…
“The Deception behind the arguments used to ban light bulbs and other products”
13 point referenced rundown http://tonn.ie
It’s hardly an indictment of CFLs
From the abstract -
“Cells exposed to CFLs exhibited a decrease in the proliferation rate, a significant increase in the production of reactive oxygen species, and a decrease in their ability to contract collagen. Measurements of UV emissions from these bulbs found significant levels of UVC and UVA (mercury [Hg] emission lines), which appeared to originate from cracks in the phosphor coatings, present in all bulbs studied. The response of the cells to the CFLs was consistent with damage from UV radiation, which was further enhanced when low dosages of TiO2 nanoparticles (NPs), normally used for UV absorption, were added prior to exposure. ”
These were cells in a petri dish. It was the equivalent of staring into a CFL from an inch away. And they enhanced the effect with titanium dioxide.
Yes that study and the ones before it hardly great shakes in an overall CFL critical aspect EU/UK/Canada on similar basis recommending (typically) double covered lamps when within 30cm (1 foot) of the bulb for 1 hour or longer
….still it lays another straw to the stack, as it were.
Much hyped LED replacement bulbs (whether white or RGB type) have a lot of light quality issues too, as per mentioned link – conveniently not mentioned by proponents when singing their energy saving or lifespan praises.!
I’ll admit that there is room for the technology to improve, or a better technology emerge. But imagine if incandescent bulbs were the new technology, people would be up in arms about how hot they are, with a significant danger of burns and capable of setting things on fire.