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One-year, simultaneous combined exposure of CDMA and WCDMA radiofrequency electromagnetic fields to rats.

No Effects Found

Jin YB, Lee HJ, Seon Lee J, Pack JK, Kim N, Lee YS. · 2011

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One year of high-level cell phone radiation exposure caused blood chemistry changes in rats, even at levels deemed 'safe' by researchers.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to cell phone radiation from both CDMA and WCDMA technologies (the frequencies used by older 2G and 3G networks) for 45 minutes daily over one full year. The exposure levels were set at 4 W/kg total, which is four times higher than current safety limits. While most health measures remained normal, the study found some changes in blood chemistry and blood cell counts, though no increase in tumors or overall illness.

Why This Matters

This study provides important data on long-term exposure to multiple wireless frequencies simultaneously, which better reflects real-world conditions where we're exposed to various cell tower and device signals at once. The 4 W/kg exposure level is notably high - four times the current SAR limit of 1 W/kg for cell phones and far above typical environmental exposures from cell towers. The fact that researchers observed changes in blood parameters, even while concluding no major health effects occurred, highlights a critical point about EMF research: biological changes can occur without immediately manifesting as obvious disease. These subtle alterations in blood chemistry deserve attention, as they may represent early indicators of physiological stress that could compound over longer exposure periods or in combination with other environmental factors.

Exposure Details

SAR
2, 4 W/kg
Source/Device
849 MHz and 1.95 GHz
Exposure Duration
45 min/ day 5 days per week for a total of one year.

Exposure Context

This study used 2, 4 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 2, 4 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)This level is 1 times the FCC limit
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 849 MHz - 1.95 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 849 MHz - 1.95 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

We investigated whether one-year, long-term, simultaneous exposure to code division multiple access (CDMA; 849 MHz) and wideband code division multiple access (WCDMA; 1.95 GHz) radiofrequencies (RF) would induce chronic illness in Sprague-Dawley (SD) rats.

Two groups of 40 SD rats (50% males and females in sham and exposed groups) were exposed to CDMA and...

The mortality patterns in male and female rats exposed to RF were compared with those found in gende...

Our results suggest that one-year chronic exposure to CDMA (849 MHz) and WCDMA (1.95 GHz) RF simultaneously at 2.0 W/kg for 45-min RF exposure periods (total, 4 W/kg) did not increase chronic illness in rats, although there were some altered parameters in the complete blood count and serum chemistry.

Cite This Study
Jin YB, Lee HJ, Seon Lee J, Pack JK, Kim N, Lee YS. (2011). One-year, simultaneous combined exposure of CDMA and WCDMA radiofrequency electromagnetic fields to rats. Int J Radiat Biol. 87(4):416-423, 2011.
Show BibTeX
@article{yb_2011_oneyear_simultaneous_combined_exposure_3116,
  author = {Jin YB and Lee HJ and Seon Lee J and Pack JK and Kim N and Lee YS.},
  title = {One-year, simultaneous combined exposure of CDMA and WCDMA radiofrequency electromagnetic fields to rats.},
  year = {2011},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/21171939/},
}
PubMed: 21171939

Cited By (26 papers)

Quick Questions About This Study

A one-year study exposing rats to CDMA and WCDMA cell phone radiation found no increase in tumors or cancer. Researchers used radiation levels four times higher than current safety limits, yet tumor rates remained unchanged compared to unexposed rats.
Research shows one year of daily cell phone radiation exposure caused some changes in rat blood chemistry and cell counts. However, these alterations didn't lead to illness or increased mortality rates compared to unexposed animals.
A comprehensive rat study found that daily exposure to 2G and 3G radiation for one full year didn't increase chronic illness or death rates. Some minor blood changes occurred, but overall health remained normal.
Research using CDMA and WCDMA radiation at levels four times higher than safety limits found no significant health risks in rats. While some blood parameters changed slightly, no tumors or chronic diseases developed.
A year-long study found that daily exposure to cell tower frequencies (CDMA and WCDMA) had no significant effect on rat body weight. Animals maintained normal growth patterns despite receiving high-level radiation exposure.