Journal of Biomedical Physics and Engineering

Blocking Short-Wavelength Component of the Visible Light Emitted by Smartphones’ Screens Improves Human Sleep Quality

Document Type : Original Research

Authors

S A R Mortazavi 1
S Parhoodeh 2
M A Hosseini 3
H Arabi 1
H Malakooti 1
S Nematollahi 4
G Mortazavi 3
L Darvish 5
S M J Mortazavi 3, 6

1 Student Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Physics Department, Shiraz branch, Islamic Azad University, Shiraz, Iran

3 Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran

4 Biostatistics Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

5 Department of Radiology, Faculty of Para-Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran

6 Medical Physics and Medical Engineering Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

https://doi.org/10.31661/jbpe.v8i4Dec.647
Abstract
Background: It has been shown that short-wavelength blue component of the visible light spectrum can alter the circadian rhythm and suppress the level of melatonin hormone. The short-wavelength light emitted by smartphones’ screens can affect the sleep quality of the people who use these devices at night through suppression of melatonin.
Objectives: In this study, we examined the effects of covering the screens of smartphones with different filters (changing the effective wavelength of the light) on sleep delay time in 43 healthy students.
Materials and Methods: Volunteer students were asked to go to bed at 23:00 and to use their mobile phones in bed for watching a natural life documentary movie for 60 minutes. No filter was used for one night while amber and blue filters were used for other 2 nights. Photospectrometry method was used to determine the output spectrum of the light passing through the filters used for covering the screens of the mobile phones. The order for utilizing amber or blue filters or using no filter was selected randomly. After 1 hour, the participants were asked to record their sleep delay time measured by a modified form of sleep time record sheet.
Results: The mean sleep delay time for the “no-filter” night was 20.84±9.15 minutes, while the sleep delay times for the nights with amber and blue filters were 15.26±1.04 and 26.33±1.59 minutes, respectively.
Conclusion: The findings obtained in this study support this hypothesis that blue light possibly suppresses the secretion of melatonin more than the longer wavelengths of the visible light spectrum. Using amber filter in this study significantly improved the sleep quality. Altogether, these findings lead us to this conclusion that blocking the short-wavelength component of the light emitted by smartphones’ screens improves human sleep.

Keywords

Smartphones
Mobile Phones
Blue Light
Sleep Quality
Display
Screen
  1. Ichikawa K. Changes in blood pressure and sleep duration in patients with blue light-blocking/yellow-tinted intraocular lens (CHUKYO study). Hypertens Res. 2014;37:659-64. doi.org/10.1038/hr.2014.50. PubMed PMID: 24621473.
  2. Kozaki T, Kubokawa A, Taketomi R, Hatae K. Light-induced melatonin suppression at night after exposure to different wavelength composition of morning light. Neurosci Lett. 2016;616:1-4. doi.org/10.1016/j.neulet.2015.12.063. PubMed PMID: 26777427.
  3. Figueiro MG, Plitnick BA, Lok A, Jones GE, Higgins P, Hornick TR, et al. Tailored lighting intervention improves measures of sleep, depression, and agitation in persons with Alzheimer’s disease and related dementia living in long-term care facilities. Clin Interv Aging. 2014;9:1527-37. doi.org/10.2147/CIA.S68557. PubMed PMID: 25246779. PubMed PMCID: 4168854.
  4. Alkozei A, Smith R, Killgore WD. Exposure to blue wavelength light modulates anterior cingulate cortex activation in response to ‘uncertain’ versus ‘certain’ anticipation of positive stimuli. Neurosci Lett. 2016;616:5-10. doi.org/10.1016/j.neulet.2016.01.034. PubMed PMID: 26806862.
  5. Figueiro MG, Plitnick B, Rea MS. Pulsing blue light through closed eyelids: effects on acute melatonin suppression and phase shifting of dim light melatonin onset. Nat Sci Sleep. 2014;6:149-56. doi.org/10.2147/NSS.S73856. PubMed PMID: 25506253. PubMed PMCID: 4259558.
  6. Tosini G, Ferguson I, Tsubota K. Effects of blue light on the circadian system and eye physiology. Mol Vis. 2016;22:61-72. PubMed PMID: 26900325. PubMed PMCID: 4734149.
  7. Smolensky MH, Sackett-Lundeen LL, Portaluppi F. Nocturnal light pollution and underexposure to daytime sunlight: Complementary mechanisms of circadian disruption and related diseases. Chronobiol Int. 2015;32:1029-48. doi.org/10.3109/07420528.2015.1072002. PubMed PMID: 26374931.
  8. Ebbesen F, Vandborg PK, Madsen PH, Trydal T, Jakobsen LH, Vreman HJ. Effect of phototherapy with turquoise vs. blue LED light of equal irradiance in jaundiced neonates. Pediatr Res. 2016;79:308-12. doi.org/10.1038/pr.2015.209. PubMed PMID: 26484622.
  9. Uchida Y, Morimoto Y, Uchiike T, Kamamoto T, Hayashi T, Arai I, et al. Phototherapy with blue and green mixed-light is as effective against unconjugated jaundice as blue light and reduces oxidative stress in the Gunn rat model. Early Hum Dev. 2015;91:381-5. doi.org/10.1016/j.earlhumdev.2015.04.010. PubMed PMID: 25984653.
  10. Mahdi Z, Habiboallh G, Mahbobeh NN, Mina ZJ, Majid Z, Nooshin A. Lethal effect of blue light-activated hydrogen peroxide, curcumin and erythrosine as potential oral photosensitizers on the viability of Porphyromonas gingivalis and Fusobacterium nucleatum. Laser Ther. 2015;24:103-11. doi.org/10.5978/islsm.15-OR-09. PubMed PMID: 26246690. PubMed PMCID: 4523596.
  11. Mortazavi SM, Motamedifar M, Namdari G, Taheri M, Mortazavi AR, Shokrpour N. Non-linear adaptive phenomena which decrease the risk of infection after pre-exposure to radiofrequency radiation. Dose Response. 2014;12:233-45. doi.org/10.2203/dose-response.12-055.Mortazavi. PubMed PMID: 24910582. PubMed PMCID: 4036396.
  12. Mortazavi SM, Taeb S, Dehghan N. Alterations of visual reaction time and short term memory in military radar personnel. Iran J Public Health. 2013;42:428-35. PubMed PMID: 23785684. PubMed PMCID: 3684731.
  13. Mortazavi SM, Rouintan MS, Taeb S, Dehghan N, Ghaffarpanah AA, Sadeghi Z, et al. Human short-term exposure to electromagnetic fields emitted by mobile phones decreases computer-assisted visual reaction time. Acta Neurol Belg. 2012;112:171-5. doi.org/10.1007/s13760-012-0044-y. PubMed PMID: 22426673.
  14. Mortazavi S, Mosleh-Shirazi M, Tavassoli A, Taheri M, Mehdizadeh A, Namazi S, et al. Increased Radioresistance to Lethal Doses of Gamma Rays in Mice and Rats after Exposure to Microwave Radiation Emitted by a GSM Mobile Phone Simulator. Dose Response. 2013;11:281-92. doi.org/10.2203/dose-response.12-010.Mortazavi. PubMed PMID: 23930107. PubMed PMCID: 3682203.
  15. Mortazavi S, Mosleh-Shirazi M, Tavassoli A, Taheri M, Bagheri Z, Ghalandari R, et al. A comparative study on the increased radioresistance to lethal doses of gamma rays after exposure to microwave radiation and oral intake of flaxseed oil. Iranian Journal of Radiation Research. 2011;9:9-14.
  16. Mortavazi S, Habib A, Ganj-Karami A, Samimi-Doost R, Pour-Abedi A, Babaie A. Alterations in TSH and Thyroid Hormones following Mobile Phone Use. Oman Med J. 2009;24:274-8. doi.org/10.5001/omj.2009.56.
  17. Mortazavi SM, Daiee E, Yazdi A, Khiabani K, Kavousi A, Vazirinejad R, et al. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use. Pak J Biol Sci. 2008;11:1142-6. doi.org/10.3923/pjbs.2008.1142.1146. PubMed PMID: 18819554.
  18. Mortazavi SM, Ahmadi J, Shariati M. Prevalence of subjective poor health symptoms associated with exposure to electromagnetic fields among university students. Bioelectromagnetics. 2007;28:326-30. doi.org/10.1002/bem.20305. PubMed PMID: 17330851.
  19. Mortazavi S, Motamedifar M, Namdari G, Taheri M, Mortazavi A. Counterbalancing immunosuppression-induced infections during long-term stay of humans in space. Journal of Medical Hypotheses and Ideas. 2013;7:8-10. doi.org/10.1016/j.jmhi.2012.12.001.
  20. Mortazavi S. Safety issue of mobile phone base stations. J Biomed Phys Eng. 2013;3:1-2.
  21. Mortazavi S, Parsanezhad M, Kazempour M, Ghahramani P, Mortazavi A, Davari M. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers. J Hum Reprod Sci. 2013;6:124-8. doi.org/10.4103/0974-1208.117178. PubMed PMID: 24082653. PubMed PMCID: 3778601.
  22. Rafati A, Rahimi S, Talebi A, Soleimani A, Haghani M, Mortazavi SM. Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study. J Biomed Phys Eng. 2015;5:133-42. PubMed PMID: 26396969. PubMed PMCID: 4576874.
  23. Shekoohi Shooli F, Mortazavi SA, Jarideh S, Nematollahii S, Yousefi F, Haghani M, et al. Short-Term Exposure to Electromagnetic Fields Generated by Mobile Phone Jammers Decreases the Fasting Blood Sugar in Adult Male Rats. J Biomed Phys Eng. 2016;6:27-32. PubMed PMID: 27026952. PubMed PMCID: 4795326.
  24. Mortazavi SMJ, Tavassoli A, Ranjbari F, Moammaiee P. Effects of laptop computers’ electromagnetic field on sperm quality. Journal of Reproduction & Infertility. 2010;11(4).
  25. Mortazavi SM, Vazife-Doost S, Yaghooti M, Mehdizadeh S, Rajaie-Far A. Occupational exposure of dentists to electromagnetic fields produced by magnetostrictive cavitrons alters the serum cortisol level. J Nat Sci Biol Med. 2012;3:60-4. doi.org/10.4103/0976-9668.95958. PubMed PMID: 22690053. PubMed PMCID: 3361780.
  26. Mortazavi SM, Neghab M, Anoosheh SM, Bahaeddini N, Mortazavi G, Neghab P, et al. High-field MRI and mercury release from dental amalgam fillings. Int J Occup Environ Med. 2014;5:101-5. PubMed PMID: 24748001.
  27. Mortazavi SM, Daiee E, Yazdi A, Khiabani K, Kavousi A, Vazirinejad R, et al. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use. Pak J Biol Sci. 2008;11:1142-6. doi.org/10.3923/pjbs.2008.1142.1146. PubMed PMID: 18819554.
  28. Mahmoudi R, Mortazavi S, Safari S, Nikseresht M, Mozdarani H, Jafari M, et al. Effects of microwave electromagnetic radiations emitted from common Wi-Fi routers on rats’ sperm count and motility. Int J Radiat Res. 2015;13:363-8.
  29. Haghnegahdar A, Khosrovpanah H, Andisheh-Tadbir A, Mortazavi G, Saeedi Moghadam M, Mortazavi S, et al. Design and fabrication of helmholtz coils to study the effects of pulsed electromagnetic fields on the healing process in periodontitis: preliminary animal results. J Biomed Phys Eng. 2014;4:83-90. PubMed PMID: 25505775. PubMed PMCID: 4258865.
  30. Paknahad M, Shahidi S, Mortazavi SMJ, Mortazavi G, Moghadam MS, Nazhvani AD. The Effect of Pulsed Electromagnetic Fields on Microleakage of Amalgam Restorations: An in Vitro Study. Shiraz E-Medical Journal. 2016;17(2).
  31. Oh JH, Yoo H, Park HK, Do YR. Analysis of circadian properties and healthy levels of blue light from smartphones at night. Sci Rep. 2015;5:11325. doi.org/10.1038/srep11325. PubMed PMID: 26085126. PubMed PMCID: 4471664.
  32. MortazaVI SMJ, Mortazavi SA, Habibzadeh P, Mortazavi G. Is it Blue Light or Increased Electromagnetic Fields which Affects the Circadian Rhythm in People who Use Smartphones at Night. Iranian journal of public health. 2016;45:405-6.
  33. Yogesh S, Abha S, Priyanka S. Mobile usage and sleep patterns among medical students. Indian J Physiol Pharmacol. 2014;58:100-3. PubMed PMID: 25508317.
  34. Redmayne M, Smith E, Abramson MJ. The relationship between adolescents’ well-being and their wireless phone use: a cross-sectional study. Environ Health. 2013;12:90. doi.org/10.1186/1476-069X-12-90. PubMed PMID: 24148357. PubMed PMCID: 4015920.
  35. Singh S, Mani KV, Kapoor N. Effect of occupational EMF exposure from radar at two different frequency bands on plasma melatonin and serotonin levels. Int J Radiat Biol. 2015;91:426-34. doi.org/10.3109/09553002.2015.1004466. PubMed PMID: 25565559.
  36. El-Helaly M, Abu-Hashem E. Oxidative stress, melatonin level, and sleep insufficiency among electronic equipment repairers. Indian J Occup Environ Med. 2010;14:66-70. doi.org/10.4103/0019-5278.75692. PubMed PMID: 21461157. PubMed PMCID: 3062017.
  37. Singh KC. Basic Physics: PHI Learning Pvt. Ltd.; 2009. p. 424.
  38. Ayaki M, Hattori A, Maruyama Y, Nakano M, Yoshimura M, Kitazawa M, et al. Protective effect of blue-light shield eyewear for adults against light pollution from self-luminous devices used at night. Chronobiol Int. 2016;33:134-9. doi.org/10.3109/07420528.2015.1119158. PubMed PMID: 26730983
Journal of Biomedical Physics and Engineering
Volume 8, Issue 4 - Serial Number 4
30
Autumn 2018
Pages 375-380

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