Publication date:
March 2025
Published in:
Journal of Biophotonics
ARPANSA review:
1 April 2025
Summary
This in vitro study explored the effects of blue light exposure on two types of DNA damage that are established effects of ultraviolet (UV) radiation exposure. Two different cell types were irradiated with a commercially available blue light therapy device emitting 417 nanometre (nm) wavelength light at a fixed intensity. The cells were exposed for varying durations to provide doses of blue light between 15-45 J/cm2. UVB radiation was used as a positive control. After irradiation, DNA was isolated from the cells and evaluated for the two hallmark DNA malformations caused by UV radiation. There was no evidence of DNA damage from any duration of blue light exposure. In contrast, exposure to UV radiation resulted in the formation of both types of DNA damage as expected.
Commentary by ARPANSA
Interest in the health effects of blue light exposure has heightened due to an increasing prevalence of LED lighting and emerging research on the relationship between blue light exposure and aspects of health like sleep (Brown, T. et al., 2022). It should be noted that the blue light emitted by personal devices is approximately 0.05-0.1% as intense as the blue light therapy device used in this study and is also of longer wavelength (Hipolito, V. & Coelho, J. 2024). This study evaluated the effect of a blue light therapy device on two types of DNA damage that are well established responses to UV radiation exposure (Mizutani, R. & Yokoyama, H., 2014; You, Y. et al., 2001). These types of DNA damage are of interest for blue light due to the proximity of the blue light wavelength (417 nm in this experiment) to the UV region of the electromagnetic spectrum (100-400 nm).
The current study demonstrated no evidence of DNA damage from blue light exposure. Similarly, the research underpinning the effectiveness of different UV wavelengths in causing sunburn (Young, A. et al., 1998; Diffey, B. et al., 1997) shows that, as the wavelength of light approaches the blue light region, the effects rapidly decrease. Although this is an encouraging result, the DNA malformations assessed in this study are not the only mechanisms of DNA damage. A more generalisable measure of DNA damage such as a comet assay may have provided additional information. Other risks of exposure from light therapy devices, such as the risk of eye damage, should also be considered when evaluating their safety, and these risks should be counterbalanced against the purported benefits of exposure. ARPANSA’s evaluation on the topic of health effects from blue light exposure is that current research is inconclusive, with conflicting evidence between studies. The International Commission on Non-Ionizing Radiation Protection has released a statement (ICNIRP, 2024) recommending improvements for future study design so that the need to establish exposure guidelines can be adequately evaluated.
