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Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus).

No Effects Found

Lerchl A, Krüger H, Niehaus M, Streckert JR, Bitz AK, Hansen V. · 2008

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Cell phone radiation at legal exposure limits caused measurable weight gain in hamsters, suggesting metabolic effects ignored by current safety standards.

Plain English Summary

Summary written for general audiences

German researchers exposed hamsters to cell phone radiation 24 hours a day for 60 days at levels matching the maximum allowed for humans. While melatonin levels (the sleep hormone) remained unchanged, hamsters exposed to certain frequencies gained up to 6% more body weight than unexposed animals, suggesting the radiation may affect metabolism even at supposedly safe levels.

Why This Matters

This study reveals something the wireless industry rarely discusses: EMF exposure at legally permitted levels can trigger measurable biological changes, even when it doesn't affect the specific endpoint being studied. The fact that hamsters gained significant weight when exposed to 900 MHz radiation (the frequency used by many cell towers and older phones) points to metabolic disruption that current safety standards don't account for. The exposure level of 0.08 W/kg represents the maximum whole-body SAR allowed for the general public in Germany and many other countries. What makes this research particularly valuable is its rigorous methodology using 240 animals across three different frequencies, with proper blinding and sham controls. The researchers' conclusion that metabolic effects need more investigation should concern anyone who assumes current safety limits protect against all biological effects.

Exposure Details

SAR
0.08 W/kg
Source/Device
383, 900, and 1800 MHz
Exposure Duration
24 hr/day for 60 days

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 0.08 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Severe Concern range (Building Biology)FCC limit is 20 times higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 1.80 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 1.80 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The aim of this study is to investigate Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus).

In three experiments, adult male Djungarian hamsters (Phodopus sungorus) were exposed 24 hr/day for ...

In all experiments, pineal and serum melatonin levels as well as the weights of testes, brain, kidne...

The data are in accordance with the hypothesis that absorbed RF energy may result in metabolic changes which eventually cause body weight increases in exposed animals. The data support the notion that metabolic effects of RF-EMFs need to be investigated in more detail in future studies.

Cite This Study
Lerchl A, Krüger H, Niehaus M, Streckert JR, Bitz AK, Hansen V. (2008). Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus). J Pineal Res. 44(3):267-272, 2008.
Show BibTeX
@article{a_2008_effects_of_mobile_phone_3193,
  author = {Lerchl A and Krüger H and Niehaus M and Streckert JR and Bitz AK and Hansen V.},
  title = {Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus).},
  year = {2008},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/18339122/},
}
PubMed: 18339122

Cited By (53 papers)

View all 53 citing papers on Semantic Scholar

Quick Questions About This Study

German researchers found that Djungarian hamsters exposed to 900 MHz radiation for 60 days gained up to 6% more body weight than unexposed animals. The weight gain was significant and persistent, while 383 MHz caused only temporary weight increases and 1800 MHz showed no effect.
A 2008 study found that hamsters exposed to cell phone frequencies (383, 900, and 1800 MHz) for 60 days showed no changes in melatonin levels. Both pineal gland and blood melatonin remained normal despite 24-hour daily exposure at maximum human safety limits.
Yes, research shows frequency-specific effects on metabolism. Hamsters exposed to 900 MHz radiation gained 6% body weight, 383 MHz caused temporary 4% weight gain, while 1800 MHz produced no weight changes. This suggests different frequencies affect metabolism differently.
German researchers found that continuous 60-day exposure to cell phone radiation did not affect organ weights in hamsters. Brain, kidney, liver, and testicular weights remained normal across all tested frequencies (383, 900, and 1800 MHz) despite significant body weight increases.
Yes, this study demonstrates that cell phone radiation at nonthermal SAR values can cause metabolic changes. Hamsters showed significant weight gain from 900 MHz exposure without any heating effects, suggesting biological impacts occur below supposedly safe thermal thresholds.