Research has shown that CFLs can expose skin to the same kind of damage associated with UV radiation. But how serious are the risks? Callum Fitzpatrick reports.

Although compact fluorescent lamps (CFLs) undoubtedly save energy compared to their incandescent counterparts, research has come to light which claims that they could be responsible for a host of health problems, including skin damage, photosensitive epilepsy, Meniere’s disease and migraines.

In early 2012, a team of researchers at Stony Brook University in New York, US investigated the impact of a CFL’s UV rays on healthy human skin tissue.

The researchers at Stony Brook’s Advanced Energy Research and Technology Centre (AERTC) collected CFLs purchased from different areas of New York State and measured the amount of ultraviolet (UV) emissions, as well as the integrity of each bulb’s phosphor coatings. Results revealed significant levels of UVC and UVA rays, which seemed to originate from cracks in the phosphor coatings.

Following this, the team studied the effects of exposure on healthy human skin tissue cells, including: fibroblasts, a type of cell found in connective tissue that produces collagen, and keratinocytes, an epidermal cell that produces keratin, the key structural material in the outer layer of human skin. Tests were repeated with incandescent light bulbs of the same intensity and also with the introduction of Titanium Dioxide (TiO2) nanoparticles, which are found in personal care products normally used for UV absorption.

“Our study revealed that the response of healthy skin cells to UV emitted from CFL bulbs is consistent with damage from UV radiation,” says team leader Professor Miriam Rafailovich.

“Skin cell damage was further enhanced when low dosages of TiO2 nanoparticles were introduced to the skin cells prior to exposure.”

Miriam adds that incandescent light of the same intensity had no effect on healthy skin cells, with or without the presence of TiO2.

“The damage to skin tissue due to UV is well documented and can lead to burns, melanoma, basal carcinoma, among other problems,” she says.

“This can lead to skin cancer, retinal cancer, burns and impaired corneal function.”

Miriam says that it is because of the common cracks in the phosphor coating which allows UV rays to escape the bulb.

“The CFL works by exciting the mercury vapour UV excitation lines, which in turn stimulate the phosphor coating on the inside of the tube. This converts the UV radiation into visible light,” Miriam says.

“If the outer phosphor layer is cracked, the UV rays are emitted from the bulb and can do damage. The cracks may appear when the glass of the bulb is ‘twisted’ to get the compact shape.

“The problem is that the phosphor is so brittle, it is very easy to crack.”

Miriam explains that for manufacturers to reduce the risks, they need to decrease the risk of the phosphor coating being compromised.

“The ‘party’ bulbs that we tested had much smaller UV emissions – completely in the negligible range. The difference was that these bulbs had the phosphor encased in some type of flexible polymer which could take the sharp bending without cracking.”

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) also conducted a study into a range of CFLs, incandescent light bulbs and halogen lamps. They say that although some CFLs emit slightly more UV light than incandescent light bulbs, these emissions are not significant if the CFLs are installed more than 25cm away from people, such as in ceiling fittings.

Of the tested lamps, the ones with the highest UV levels were measured at a distance of 10cm over a period of eight hours and this is said to be the equivalent of spending approximately six minutes in the midday summer sunshine in Brisbane and seven minutes in Melbourne.

ARPANSA advises that if people are concerned about UV exposure they should minimise the time spent closer than 25cm from these lamps or use ‘double envelope’ or ‘covered’ CFLs (lamps which have an appearance similar to the traditional pear-shaped incandescents).

However, if a person is highly photosensitive, they should be extra-cautious, especially those who suffer from a condition like systemic lupus erythematosus (or lupus – an autoimmune disorder characterised by chronic inflammation of body tissues. Exacerbations or flare-ups can be induced by exposure to any form of UV emission, including sunlight).

“Despite their large energy savings, we need to be careful when using CFL bulbs,” Miriam says.

“Our research shows that it is always best to keep them at a distance. They are also much safer when they are placed behind an additional glass cover.”

Double envelope CFLs have a cover (which is usually glass or plastic) over the spiral or bent glass tube. This second envelope can block most of the UV emitted from the bulb. Additionally, traditional covers and lamp shades are usually UV absorbent.

The CFL ‘flicker’
The ‘flicker’ from CFLs has also been reported to have a detrimental effect on people with conditions such as photosensitive epilepsy, Ménière’s disease and migraines.

However, ARPANSA says that CFLs flicker at over 20,000 times per second, modern linear fluorescent tubes at more than 5,000 times per second, and older style linear fluorescents at 100 times per second. These rates of flickering are well above the ‘sensitive range’ for flicker vertigo and are above that detectable by the human brain.

A flicker should only be of a concern if it is developed from a fault in the bulb. This can cause them to have a much more noticeable, slower flicker. These lamps should be replaced immediately.