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Home » Archived » The Effects of UV Emission from CFL Exposure on Human Dermal Fibroblasts and Keratinocytes in Vitro.

The Effects of UV Emission from CFL Exposure on Human Dermal Fibroblasts and Keratinocytes in Vitro.

June 13 2012

The American Society of Photobiology

Tatsiana Mironava, Michael Hadjiargyrou, Marcia Simon, Miriam H. Rafailovich.


Compact fluorescent light (CFL) bulbs can provide the same amount of lumens as
incandescent light bulbs, using one quarter of the energy. Recently CFL exposure was found to
exacerbate existing skin conditions, however the effects of CFL exposure on healthy skin tissue
has not been thoroughly investigated. In this report, we studied the effects of exposure to CFL
illumination on healthy human skin tissue cells (fibroblasts and keratinocytes). Cells exposed to
CFLs exhibited a decrease in the proliferation rate, a significant increase in the production of
ROS (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. No effect on cells, with or
without TiO2 NPs, was observed when they were exposed to incandescent light of the same


The data presented herein confirm that higher than expected levels of UVA and UVC
irradiation can be emitted by commercially available CFL bulbs as a result of the limitation of
the current production process and the possible physical defects in the bulbs where the
phosphorus coating was compromised. Skin cells exposed to the CFL exhibit 25% and 50%
attrition for DO33 and CF-29, respectively. For the surviving cells, a significant increase in the
production of ROS, and in the case of the CF-29, a decrease in their ability to contract collagen
and abnormal migration behavior, are observed and consistent with previous reports of exposure
to UVA and UVC radiation.
In addition, we also examined the effects of CFL in conjunction to the exposure of cells
to low dosages (0.1 μg/ml) of anatase and rutile TiO2 NPs prior to irradiation. In the absence of
exposure to CFL, this dose was found to have minimal or no effects on the cells. In contrast, after even a single exposure to CFLcells containing anatase died. Cells containing rutile
sustained slightly more damage than the cells without NPs after a single CFL exposure, but were
completely destroyed following a second one. In contrast, cells without NPs sustained less
damage after the second CFL exposure. Even though both keratinocytes and dermal fibroblasts
sustained damage after exposure to the CFL, the extent was larger for fibroblasts. Illumination
of all cell to incandescent light (where no UV emissions were detected), had no significant effect
on proliferation, ROS production, or mitochondrial activity. Taken together, our results confirm
that UV radiation emanating from CFL bulbs (randomly selected from different suppliers) as a
result of defects or damage in the phosphorus coating is potentially harmful to human skin.

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