Seyed Ali Reza Mortazavi - College of Medical, Veterinary & Life Sciences, University of Glascow, Glasgow, GB
Sedigheh Tahmasebi - Breast Cancer Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
James C Lech - Department of Radiology and Nuclear Medicine, Academic Medical Center, University of Amsterdam (UMC), Amsterdam, The Netherlands
James S Welsh - Department of Radiation Oncology, Stritch School of Medicine Loyola University Chicago, Maywood, IL, USA
Abdorasoul Taleie - School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Abbas Rezaianzadeh - School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Ali Zamani - Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Kanu Mega - School of Life Sciences, Manipal Academy of Higher Education, Dubai International Academic City, Dubai, UA
Samaneh Nematollahi - Noncommunicable Diseases Research Center, Bam University of Medical Sciences, Bam, Iran
Atefeh Zamani - School of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales, Australia
Seyed Mohammad Javad Mortazavi - Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
Lembit Sihver - Department of Radiation Physics, Atominstitut, Technische Universität Wien, Vienna, Austria

Background: As the use of electronic devices such as mobile phones, tablets, and computers continues to rise globally, concerns have been raised about their potential impact on human health. Exposure to high energy visible (HEV) blue light, emitted from digital screens, particularly the so-called artificial light at night (ALAN), has been associated with adverse health effects, ranging from disruption of circadian rhythms to cancer. Breast cancer incidence rates are also increasing worldwide. Objective: This study aimed at finding a correlation between breast cancer and exposure to blue light from mobile phone. Material and Methods: In this retrospective matched case-control study, we aimed to investigate whether exposure to blue light from mobile phone screens is associated with an increased risk of female breast cancer. We interviewed ۳۰۱ breast cancer patients (cases) and ۲۹۴ controls using a standard questionnaire and performed multivariate analysis, chi-square, and Fisher’s exact tests for data analysis. Results: Although heavy users in the case group of our study had a statistically significant higher mean ۱۰-year cumulative exposure to digital screens compared to the control group (۷۰۸۹±۱۴۹۸۵ vs ۴۰۵۲±۱۲۵۱۵ hours, respectively, P=۰.۰۳۸), our study did not find a strong relationship between exposure to HEV and development of breast cancer.  Conclusion: Our findings suggest that heavy exposure to HEV blue light emitted from mobile phone screens at night might constitute a risk factor for promoting the development of breast cancer, but further large-scale cohort studies are warranted.

Visible Light, Blue Light, Mobile Phones, Digital Screens, cancer, Breast cancer, Circadian Disruption, Melatonin, Light Pollution, Screen Time, circadian rhythm