Light sensitivity
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Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include:
- Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders)
- Intensity of light (photophobia, sunburn, skin cancer)
- Wavelength of light ( in lupus, urticaria )
- Rapid flickers in intensity of light may trigger or aggravate epilepsy or migraine headaches.
Other effects may include vertigo, or chronic fatigue syndrome.
In rare cases individuals with solar urticaria (allergy to sunlight) can get a rash from fluorescent lighting [1] or may experience disease activity in very photosensitive individuals with Systemic lupus erythematosus. Standard acrylic diffusers over the fluorescent lamps absorb nearly all the UV-B radiation and appear to protect against this.[2]
In rare cases, fluorescent lighting can also induce depersonalization and derealization, subsequently, it can worsen depersonalization disorder symptomology.[3] Research on these rare cases is very limited and cause and effect often cannot be duplicated.
Controlled application of artificial light can be used in a program of Light therapy to treat some disorders.
Contents
- 1 Ultraviolet radiation risk
- 2 Skin and retinal cancers
- 3 Migraine
- 4 Autism and Asperger syndrome
- 5 Ménière's disease and Vertigo
- 6 Polymorphous light eruption
- 7 Chronic actinic dermatitis
- 8 Lupus
- 9 Actinic Prurigo
- 10 Solar Urticaria
- 11 Phytophotodermatitis
- 12 Additional risk for patients undergoing photodynamic therapy
- 13 Chronic fatigue syndrome
- 14 Cataracts
- 15 Photophobia
- 16 Epilepsy
- 17 Dyslexia
- 18 Fluorescent lamps
- 19 See also
- 20 References
Ultraviolet radiation risk
Some fluorescent lamps emit ultraviolet radiation that in some circumstances can exceed safe levels. The Health Protection Agency of the United Kingdom has conducted research that concluded exposure to some compact fluorescent lamps (CFLs) for 1 hour per day at a distance of less than 30 cm can exceed safe levels. Touching the exposed bulb results in equivalent exposure to ultraviolet radiation as that of being in direct summer sunlight.[4]
Skin and retinal cancers
Ultraviolet radiation emitted by fluorescent lighting increases an individual's exposure to carcinogenic radiation by 10 to 30 per cent per year, with an associated increased probability of contracting squamous cell carcinoma by 4 percent [5]. Melanoma has been shown to not be affected by CFLs through normal use [5] The constituent blue light of CFLs can aggravate retinal diseases in susceptible people, but it is unlikely to occur [5]
Migraine
Blue light, such as that emitted by CFLs, can aggravate migraine [5] and fluorescent lamps can cause eye-strain and headache. [5] There is no available data on the existence of CFL-induced migraine but there is anecdotal evidence of "problems" with blue light. </ref> The charity Migraine Action [1] says its members suffer migraines induced by CFLs[6] and there are many anecdotal reports of such occurrences.[7][8]
Autism and Asperger syndrome
The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) report states that "people with Autism/Aspergers syndrome have reported problems which they attributed to fluorescent lighting and any deleterious effects on sufferers of autism or Asperger Syndrome from CFLs cannot be dismissed [5].
Ménière's disease and Vertigo
The inner-ear condition Ménière's disease can be aggravated by flicker [5] Sufferers of vertigo are recommended to not use fluorescent lights. [5]
Polymorphous light eruption
Polymorphous light eruption is a condition affecting the skin thought to be caused by an adverse reaction to ultraviolet light. Its prevalence across Europe is 10-20% of the population [5] Artificial light sources may provoke the condition, and CFLs have been shown to produce an eruption.[5]
Chronic actinic dermatitis
Chronic actinic dermatitis is a condition where a subject's skin becomes inflamed due to a reaction to sunlight or artificial light. Its prevalence in Scotland is 16.5 per 100,000 population. There is evidence that CFLs worsen the condition. [5]
Lupus
The autoimmune disease Lupus is exacerbated by CFLs. [5]
Actinic Prurigo
There is evidence that Actinic prurigo is worsened by CFLs [5]. This disease affects 3.3% of the general population.
Solar Urticaria
3.1% of the population suffer Solar urticaria, a skin disorder affected by ultraviolet light. Some patients are directly affected by CFLs. [5]
Phytophotodermatitis
Phytophotodermatitis may be aggravated by the additional levels of ultraviolet light emitted by CFLs. [5]
Additional risk for patients undergoing photodynamic therapy
Patients undergoing photodynamic therapy are at additional risk of adverse photosensitive reactions caused by CFLs. [5]
Chronic fatigue syndrome
Self-reporting suggests that 21% of chronic fatigue syndrome patients experience sensitivity to light and there have been no studies into the association between chronic fatigue syndrome and CFLs. [5].
Cataracts
One cause of cataracts is exposure to ultraviolet light. Provided the level of UV emission from lamps is within safe limits, and the lamp a sufficient distance away from the individual, there should be no increased risk of developing cataracts. [5]
Photophobia
Photophobia is a symptom of excessive sensitivity to light which affects 5 to 20% of the population. No studies have been conducted into the effect of CFLs on sufferers of photophobia but there is the possibility for CFLs to affect sufferers [5]
Epilepsy
There is evidence that flicker can cause seizures in patients with photosensitive epilepsy, but there has yet to be any evidence to date attributing seizures to compact fluorescent lamps [5]
Dyslexia
Self-reporting suggests fluorescent lamps aggravate dyslexia, [5] Tests show that dyslexic patients are unable to detect flicker emanating from light sources. [5]
Fluorescent lamps
Nocturnal exposure to light in the short wavelength ranges (below 530 nm) generated by some fluorescent lamps may interfere with mammalian circadian rhythms due to its suppressing effect on melatonin production.[9] Suppression of melatonin has been linked to cancer in some studies.
Fluorescent lamps with magnetic ballasts flicker at a normally unnoticeable frequency of 100 or 120 hertz and this flickering can cause problems for some individuals with light sensitivity,[10] they are listed as problematic for some individuals with autism, epilepsy,[11] lupus,[12] chronic fatigue syndrome, and vertigo.[13] Newer fluorescent lights without magnetic ballasts have essentially eliminated flicker.[14] In rare cases, fluorescent lighting can also induce depersonalization and derealization, subsequently, it can worsen depersonalization disorder symptomology.[3] Research on these rare cases is very limited and cause and effect often cannot be duplicated.
The normally unnoticeable 100–120 Hz flicker from fluorescent tubes powered by electromagnetic ballasts are associated with headaches and eyestrain. Individuals with high flicker fusion threshold are particularly affected by electromagnetic ballasts: their EEG alpha waves are markedly attenuated and they perform office tasks with greater speed and decreased accuracy.[15] Ordinary people have better reading performance using high frequency (20 kHz – 60 kHz) electronic ballasts than electromagnetic ballasts.[16]
Early studies suspected a relationship between the flickering of fluorescent lamps with electromagnetic ballasts and repetitive movement in autistic children.[17] However, these studies had interpretive problems[18] and have not been replicated.
See also
- Asthenopia (eye strain)
- Photophobia
- Phototoxicity
References
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- ↑ Beattie PE, Dawe RS, Ibbotson SH, Ferguson J (2003). "Characteristics and prognosis of idiopathic solar urticaria: a cohort of 87 cases". Arch Dermatol. 139 (9): 1149–54. doi:10.1001/archderm.139.9.1149. PMID 12975156.
- ↑ Rihner M, McGrath H Jr (1992). "Fluorescent light photosensitivity in patients with systemic lupus erythematosus". Arthritis Rheum. 35 (8): 949–52. doi:10.1002/art.1780350816. PMID 1642660.
- ↑ 3.0 3.1 Simeon D, Knutelska M, Nelson D & Guralnik O. (2003) Feeling unreal: a depersonalization disorder update of 117 cases. Journal of Clinical Psychiatry 64 (9): 990-7 PMID 14628973
- ↑ "Emissions from compact fluorescent lights" (PDF). Health Protection Agency. 2008. Retrieved 2009-08-31.
- ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 "Light Sensitivity, Scientific Committee on Emerging and Newly Identified Health Risks" (PDF). Director-General for Health and Consumers, European Commission. 2008. pp. 26–27. Retrieved 2009-08-31.
Although the carcinogenic UV dose from fluorescent lighting in offices is minor (~ 1%) when compared to equal exposure times in the summer sun, old risk assessments showed that actual annual exposures of office workers could increase by 10 to 30% from the fluorescent lighting, which over a lifetime was estimated to increase the risk of squamous cell carcinomas by around 4 % with a baseline risk much lower than that for outdoor workers who dominate incidences (Lytle et al 1992).
- ↑ "EU phases out low efficency (sic) light bulbs". Migraine Action. 2009. Retrieved 2009-09-04.
However as reported regularly by Migraine Action, there are concerns - voiced my many members - that the new bulbs can cause migraines.
- ↑ "Low-energy bulbs 'cause migraine'". BBC. 2008-01-02. Retrieved 2009-09-04.
- ↑ "Phasing out 100W lightbulbs 'could damage health of Britons'". London: Daily Telegraph. 2009-08-31. Retrieved 2009-09-04.
- ↑ "Prevention of melatonin suppression by nocturnal lighting: relevance to cancer". Eur J Cancer Prev. author=Kayumov L, Lowe A, Rahman SA, Casper RF, Shapiro CM. 2007. PMID 17554209.
- ↑ "Working with Light Sensitivity".
- ↑ "Accommodation Ideas for Employees with Epilepsy".
- ↑ "Accommodation and Compliance Series: Employees with Lupus".
- ↑ "Accommodating People with Vertigo".
- ↑ http://www.ccohs.ca/oshanswers/ergonomics/lighting_flicker.html Lighting flicker, retrieved 2010 April 19
- ↑ Küller R, Laike T (1998). "The impact of flicker from fluorescent lighting on well-being, performance and physiological arousal". Ergonomics. 41 (4): 433–47. doi:10.1080/001401398186928. PMID 9557586.
- ↑ Veitch JA, McColl SL (1995). "Modulation of fluorescent light: flicker rate and light source effects on visual performance and visual comfort". Light Res Tech. 27 (4): 243–256. doi:10.1177/14771535950270040301. Retrieved 2007-08-12.
- ↑ Colman RS, Frankel F, Ritvo E, Freeman BJ (1976). "The effects of fluorescent and incandescent illumination upon repetitive behaviors in autistic children". J Autism Child Schizophr. 6 (2): 157–62. doi:10.1007/BF01538059. PMID 989489.
- ↑ Turner M (1999). "Annotation: Repetitive behaviour in autism: a review of psychological research". J Child Psychol Psychiatry. 40 (6): 839–49. doi:10.1017/S0021963099004278. PMID 10509879.
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