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Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

DNA & Genetic Damage

Twenty four- hour exposure to a 0.12 THz electromagnetic field does not affect the genotoxicity, morphological changes, or expression of heat shock protein in HCE-T cells

No Effects Found

Koyama S, Narita E, Shimizu Y, Shiina T, Taki M, Shinohara N, et al. · 2016

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24-hour exposure to 0.12 THz terahertz radiation showed no DNA damage or cellular stress in human eye cells.

Plain English Summary

Summary written for general audiences

Researchers exposed human eye cells to terahertz radiation (0.12 THz frequency) for 24 hours to test for cellular damage. The study found no DNA damage, cell structure changes, or stress protein production compared to unexposed control cells. This suggests terahertz frequencies at this power level may not cause immediate cellular harm.

Why This Matters

This study provides reassuring data about terahertz frequencies, which occupy the spectrum between microwaves and infrared light. The 0.12 THz frequency tested sits well above typical wireless device emissions (which operate in gigahertz ranges), but terahertz waves are increasingly used in security scanners, medical imaging, and emerging 6G wireless technologies. The researchers used a robust experimental design, testing multiple cellular damage markers including DNA breaks, cell death, and heat shock proteins that typically indicate cellular stress. While the 5 mW/cm² power density was relatively low and the 24-hour exposure represents an extreme scenario unlikely in real-world applications, the lack of detectable effects offers some confidence about terahertz safety. However, this single study on eye cells cannot definitively establish safety across all cell types or longer exposure periods.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 0.12 THz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 0.12 THzPower lines50/60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Cite This Study
Koyama S, Narita E, Shimizu Y, Shiina T, Taki M, Shinohara N, et al. (2016). Twenty four- hour exposure to a 0.12 THz electromagnetic field does not affect the genotoxicity, morphological changes, or expression of heat shock protein in HCE-T cells.
Show BibTeX
@article{twenty_four_hour_exposure_to_a_012_thz_electromagnetic_field_does_not_affect_the_genotoxicity_morphological_changes_or_expression_of_heat_shock_protein_in_hce_t_cells_ce2869,
  author = {Koyama S and Narita E and Shimizu Y and Shiina T and Taki M and Shinohara N and et al.},
  title = {Twenty four- hour exposure to a 0.12 THz electromagnetic field does not affect the genotoxicity, morphological changes, or expression of heat shock protein in HCE-T cells},
  year = {2016},
  doi = {10.3390/ijerph13080793},
  
}
DOI: 10.3390/ijerph13080793PubMed: 27527204

Quick Questions About This Study

No, this study found no DNA damage, morphological changes, or stress protein expression in human corneal epithelial cells after 24 hours of 0.12 THz exposure at 5 mW/cm², suggesting no immediate cellular harm at this frequency and power level.
The human corneal epithelial cells were continuously exposed to 0.12 THz terahertz radiation for 24 hours straight, which represents an extremely long exposure duration far exceeding typical real-world terahertz encounters from security scanners or medical devices.
Researchers examined three key indicators: micronucleus formation (DNA damage), morphological changes (cell structure alterations), and heat shock protein expression (Hsp27, Hsp70, Hsp90α), which are standard markers for detecting cellular stress and damage.
No, 0.12 THz (120 gigahertz) is much higher frequency than cell phone radiation, which typically operates between 0.7-5 GHz. Terahertz waves sit between microwave and infrared radiation on the electromagnetic spectrum, with different biological interaction properties.
The study used 5 mW/cm² power density, which is considered relatively low. For comparison, this is below typical microwave oven leakage limits and represents conservative exposure levels that might be encountered from terahertz security scanners or medical imaging equipment.