Fluorescent lamps and health

Did You Know?

• Many older fluorescent lighting installations retain ballasts containing toxic polychlorinated biphenyls.
• The Scientific Committee on Emerging and Newly Identified Health Risks reviewed connections between artificial light and human diseases in 2008 and again in 2012, finding no significant changes.
• Self-reporting suggests fluorescent lamps aggravate dyslexia, but tests show dyslexic patients cannot detect flicker from light sources.

Flicker effects

Older fluorescent lamps with magnetic ballasts flicker at 100 or 120 Hz, a frequency normally unnoticeable but capable of causing headaches and eyestrain in light-sensitive individuals. Such lamps are considered problematic for some people with autism, epilepsy, lupus, chronic fatigue syndrome, Lyme disease, and vertigo. Individuals with a high flicker fusion threshold show attenuated EEG alpha waves and perform office tasks faster but with less accuracy. Early studies suggesting a link between flicker and repetitive movement in autistic children had interpretive problems and were not replicated. Newer fluorescent lights without magnetic ballasts have essentially eliminated flicker.

Ultraviolet radiation risk

Some fluorescent lamps emit ultraviolet radiation. Exposure to open (single envelope) compact fluorescent lamps for over one hour per day at a distance of less than 30 cm can exceed guideline levels set by the International Commission on Non-Ionizing Radiation Protection. Close proximity to bare skin can result in UV exposure similar to direct sunlight. At a distance of 3 cm, recommended daily exposure limits for skin and eye damage were reached in 50 minutes to 5 hours, depending on the lamp type, though such close distances are unlikely in actual use. At 30 cm, the maximum recommended daily exposure was attained in 3 to 6 hours, with little difference between bare-spiral CFLs and a 60 watt incandescent lamp. Encapsulated (double envelope) CFLs emit less UV radiation. Outdoor sunlight can supply the maximum recommended daily UV exposure in 20 to 100 minutes.

Mercury

Fluorescent bulbs contain mercury, a toxic substance. The U.S. Environmental Protection Agency offers safety steps for cleaning up a broken bulb, and recommends that children and pregnant women stay away during cleanup. Old bulbs should not go in regular trash to avoid mercury release if they break. A compact fluorescent lamp holds about 4 to 5 milligrams of mercury, roughly one percent of the amount in a dental amalgam filling or an old glass thermometer. Some linear fluorescent lamps, called "Green" models with green caps or tips, contain as little as 1.7 milligrams. Using energy-efficient CFLs cuts power demand, which lowers mercury emissions from coal-fired power plants.

Other conditions associated with fluorescent light

In rare cases, individuals with solar urticaria may develop a rash from fluorescent lighting, as from any light source. Very photosensitive people with systemic lupus erythematosus may experience disease activity under artificial light, though standard acrylic diffusers absorb nearly all UV-B radiation and appear protective. One paper suggested that fluorescent lighting can rarely induce depersonalization and derealization, potentially worsening depersonalization disorder.