Women with hereditary breast cancer predispositions should avoid using their smartphones, tablets and laptops at night

Document Type: Editorial


1 School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Department of Diagnostic Imaging, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA 19111, USA


Breast cancer is the most common malignancy among women, both in the developed and developing countries. Women with mutations in the BRCA1 and BRCA2 genes have an increased risk of breast and ovarian cancers. Recent studies show that short-wavelength visible light disturb the secretion of melatonin and causes circadian rhythm disruption. We have previously studied the health effects of exposure to different levels of radiofrequency electromagnetic fields (RF-EMFs) such as mobile phones, mobile base stations, mobile phone jammers, laptop computers, and radars. Moreover, over the past several years, we investigated the health effects of exposure to the short wavelength visible light in the blue region emitted from digital screens. The reduction of melatonin secretion after exposure to blue light emitted from smartphone’s screen has been reported to be associated with the negative impact of smartphone use at night on sleep. We have shown that both the blue light and RF-EMFs generated by mobile phones are linked to the disruption of the circadian rhythm in people who use their phones at night. Therefore, if women with hereditary breast cancer predispositions use their smartphones, tablets and laptops at night, disrupted circadian rhythms (suppression of melatonin caused by exposure to blue light emitted from the digital screens), amplifies the risk of breast cancer. It can be concluded that women who carry mutated BRCA1 or BRCA2, or women with family history of breast cancer should avoid using their smartphones, tablets and laptops at night. Using sunglasses with amber lenses, or smartphone applications which decrease the users’ exposure to blue light before sleep, at least to some extent, can decrease the risk of circadian rhythm disruption and breast cancer.


Main Subjects

1. Jara L, Morales S, de Mayo T, Gonzalez-Hormazabal P, Carrasco V, Godoy R. Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in central and south American populations. Biol Res 2017;50:35.

2. Ghoncheh M, Pournamdar Z, Salehiniya H. Incidence and mortality and epidemiology of breast cancer in the world. Asian Pac J Cancer Prev 2016;17(S3):43-46.

3. Kuchenbaecker KB, Hopper JL, Barnes DR, Phillips KA, Mooij TM, Roos-Blom MJ, et al. Risks of breast, ovarian, and contralateral breast cancer for BRCA1 and BRCA2 mutation carriers. JAMA 2017;317:2402-2416.

4. Stevens RG, Zhu Y. Electric light, particularly at night, disrupts human circadian rhythmicity: is that a problem? Philos Trans R Soc Lond B Biol Sci 2015;370.

5. Datta K, Roy A, Nanda D, Das I, Guha S, Ghosh D, et al. Association of breast cancer with sleep pattern-a pilot case control study in a regional cancer centre in South Asia. Asian Pac J Cancer Prev 2014;15:8641-8645.

6.  Li Y, Li S, Zhou Y, Meng X, Zhang J-J, Xu D-P, et al. Melatonin for the prevention and treatment of cancer. Oncotarget. 2017; 8:39896-39921.

7. Liu Z, Zou D, Yang X, Xue X, Zuo L, Zhou Q, et al. Melatonin inhibits colon cancer RKO cell migration by downregulating Rho‑associated protein kinase expression via the p38/MAPK signaling pathway. Mol Med Rep 2017;16:9383-9392.

8. Asghari MH, Moloudizargari M, Ghobadi E, Fallah M, Abdollahi M. Melatonin as a multifunctional anti-cancer molecule: Implications in gastric cancer. Life Sci 2017; 185:38-45.

9.   Chuffa LGA, Reiter RJ, Lupi LA. Melatonin as a promising agent to treat ovarian cancer: molecular mechanisms. Carcinogenesis 2017; 38:945-952.

10. Kim T-H, Cho S-G. Melatonin-induced KiSS1 expression inhibits triple-negative breast cancer cell invasiveness. Oncol Lett 2017; 14:2511-2516.

11. Mao L, Yuan L, Slakey LM, Jones FE, Burow ME, Hill SM. Inhibition of breast cancer cell invasion by melatonin is mediated through regulation of the p38 mitogen-activated protein kinase signaling pathway. Breast Cancer Res 2010;12:R107.

12. Zou DB, Wei X, Hu RL, Yang XP, Zuo L, Zhang SM, et al. Melatonin inhibits the migration of colon cancer RKO cells by down-regulating myosin light chain kinase expression through cross-talk with p38 MAPK. Asian Pac J Cancer Prev 2015; 16:5835-5842.

13. Ordonez R, Carbajo-Pescador S, Prieto-Dominguez N, Garcia-Palomo A, Gonzalez-Gallego J, Mauriz JL. Inhibition of matrix metalloproteinase-9 and nuclear factor kappa B contribute to melatonin prevention of motility and invasiveness in HepG2 liver cancer cells. J Pineal Res. 2014; 56:20-30.

14. Zhou Q, Gui S, Zhou Q, Wang Y. Melatonin inhibits the migration of human lung adenocarcinoma A549 cell lines involving JNK/MAPK pathway. PLoS One. 2014; 9:e101132.

15. 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; 32:1029-1048.

16. Kim YJ, Lee E, Lee HS, Kim M, Park MS. High prevalence of breast cancer in light polluted areas in urban and rural regions of South Korea: An ecologic study on the treatment prevalence of female cancers based on National Health Insurance data. Chronobiol Int. 2015;32:657-667.

17. Bedrosian TA, Nelson RJ. Timing of light exposure affects mood and brain circuits. Transl Psychiatry 2017; 7:e1017.

18. Bedrosian TA, Nelson RJ. Influence of the modern light environment on mood. Mol Psychiatry 2013;18:751-757.

19. Blask DE, Brainard GC, Dauchy RT, Hanifin JP, Davidson LK, Krause JA, et al. Melatonin-depleted blood from premenopausal women exposed to light at night stimulates growth of human breast cancer xenografts in nude rats. Cancer Res 2005;65:11174-11184.

20. Fonken LK, Workman JL, Walton JC, Weil ZM, Morris JS, Haim A, et al. Light at night increases body mass by shifting the time of food intake. Proceedings of the National Academy of Sciences of the United States of America. 2010; 107:18664-18669.

21. Davies TW, Smyth T. Why artificial light at night should be a focus for global change research in the 21st century. Chronobiology international. Glob Chang Biol 2017 [Epub ahead of print]

22. Wyse CA, Selman C, Page MM, Coogan AN, Hazlerigg DG. Circadian desynchrony and metabolic dysfunction; did light pollution make us fat? Med Hypotheses. 2011; 77:1139-1144.

23. Cisse YM, Russart KLG, Nelson RJ. Depressive-like behavior is elevated among offspring of parents exposed  to dim light at night prior to mating. Psychoneuroendocrinology 2017; 83:182-186.

24. Touitou Y, Reinberg A, Touitou D. Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption. Life Sci 2017;173:94-106.

25. Ball LJ, Palesh O, Kriegsfeld LJ. The pathophysiologic role of disrupted circadian and neuroendocrine rhythms in breast carcinogenesis. Endocr Rev 2016; 37:450-466.

26. Lin X, Chen W, Wei F, Ying M, Wei W, Xie X. Night-shift work increases morbidity of breast cancer and all-cause mortality: a meta-analysis of 16 prospective cohort studies. Sleep Med 2015; 16:1381-1387.

27. Kim KY, Lee E, Kim YJ, Kim J. The association between artificial light at night and prostate cancer in Gwangju City and South Jeolla Province of South Korea. Chronobiol Int  2017; 34:203-211.

28. Cho Y, Ryu SH, Lee BR, Kim KH, Lee E, Choi J. Effects of artificial light at night on human health: A literature review of observational and experimental studies applied to exposure assessment. Chronobiol Int. 2015; 32:1294-1310.

29. Mortazavi SM, Rahimi S, Talebi A, Soleimani A, Rafati             A. Survey of the effects of exposure to 900 MHz radiofrequency radiation emitted by a GSM mobile phone on the pattern of muscle contractions in an animal model. J Biomed Phys Eng 2015; 5:121-132.

30. Mortazavi SAR, Mortazavi G, Mortazavi SMJ. Comments on "Radiofrequency electromagnetic fields and some cancers of unknown etiology: An ecological study". Sci Total Environ 2017; 609:1.

31. Zarei S, Mortazavi SM, Mehdizadeh AR, Jalalipour M, Borzou S, Taeb S, et al. A challenging issue in the etiology of speech problems: The effect of maternal exposure to electromagnetic fields on speech problems in the offspring. J Biomed Phys Eng 2015; 5:151-154.

32. Mokarram P, Sheikhi M, Mortazavi SMJ, Saeb S, Shokrpour N. Effect of exposure to 900 MHz GSM mobile phone radiofrequency radiation on estrogen receptor methylation status in colon cells of male sprague dawley rats. J Biomed Phys Eng 2017; 7:79-86.

33. Eghlidospour M, Ghanbari A, Mortazavi SMJ, Azari H. Effects of radiofrequency exposure emitted from a GSM mobile phone on proliferation, differentiation, and apoptosis of neural stem cells. Anat Cell Biol 2017; 50:115-123.

34. Taheri M, Mortazavi SM, Moradi M, Mansouri S, Hatam GR, Nouri F. Evaluation of the effect of radiofrequency radiation emitted from Wi-Fi router and mobile phone simulator on the antibacterial susceptibility of pathogenic bacteria listeria monocytogenes and Escherichia coli. Dose Response 2017; 15:1559325816688527.

35. Mortazavi SAR, Mortazavi SMJ, Paknahad M. The role of electromagnetic fields in neurological disorders. J Chem Neuroanat 2016;77:78-79.

36. 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; 112:171-175.

37. Mortazavi SM. Subjective Symptoms Related to GSM Radiation from Mobile Phone Base Stations: a cross-sectional study. J Biomed Phys Eng 2014; 4:39-40.

38. 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 2013; 12:233-245.

39. Mortazavi SM, Mahbudi A, Atefi M, Bagheri S, Bahaedini N, Besharati A. An old issue and a new look: electromagnetic hypersensitivity caused by radiations emitted by GSM mobile phones. Technol Health Care 2011; 19:435-443.

40. Mortazavi SM, Ahmadi J, Shariati M. Prevalence of subjective poor health symptoms associated with exposure to electromagnetic fields among university students. Bioelectromagnetics 2007; 28:326-330.

41. Mortazavi S. Safety issues of mobile phone base stations. J Biomed Phys Eng 2013; 3:1-2.

42. Parsaei H, Faraz M, Mortazavi S. A multilayer perceptron neural network–based model for predicting subjective health symptoms in people living in the vicinity of mobile phone base stations. Ecopsychology. 2017; 9:99-105.

43. Mortazavi G, Mortazavi SM. Increased mercury release from dental amalgam restorations after exposure to electromagnetic fields as a potential hazard for hypersensitive people and pregnant women. Rev Environ Health 2015; 30:287-292.

44. Mortazavi SA, Taeb S, Mortazavi SM, Zarei S, Haghani M, Habibzadeh P, et al. The fundamental reasons why laptop computers should not be used on your lap. J Biomed Phys Eng 2016; 6:279-284.

45. Paknahad M, Mortazavi SM, Shahidi S, Mortazavi G, Haghani M. Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations. J Environ Health Sci Eng 2016;14:12.

46. Shekoohi-Shooli F, Mortazavi SM, Shojaei-Fard MB, Nematollahi S, Tayebi M. Evaluation of the protective role of vitamin c on the metabolic and enzymatic activities of the liver in the male rats after exposure to 2.45 GHz of Wi-Fi routers. J Biomed Phys Eng. 2016; 6:157-164.

47. Taheri M, Mortazavi SM, Moradi M, Mansouri S, Nouri F, Mortazavi SA, et al. Klebsiella pneumonia, a microorganism that approves the non-linear responses to antibiotics and window theory after exposure to Wi-Fi 2.4 GHz electromagnetic radiofrequency radiation. J Biomed Phys Eng 2015; 5:115-120.

48. 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.

49. Bruni O, Sette S, Fontanesi L, Baiocco R, Laghi F, Baumgartner E. Technology use and sleep quality in preadolescence and adolescence. J Clin Sleep Med. 2015; 11:1433-1441.

50. Yoshimura M, Kitazawa M, Maeda Y, Mimura M, Tsubota K, Kishimoto T. Smartphone viewing distance and sleep: an experimental study utilizing motion capture technology. Nat Sci Sleep 2017; 9:59-65.

51. Mortazavi S, Mortazavi S, Habibzadeh P, Mortazavi G. Is it blue light or increased electromagnetic fields which affects the circadian rhythm in people who use smartphones at night. Iran J Public Health 2016; 45:405-406.