8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
Shield Your Body
Brain & Nervous System

Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens?

Bioeffects Seen

Jensh RP · 1997

View Original Abstract
Share:

Prenatal microwave exposure altered brain development in rat offspring, with higher frequencies showing clearer neurological effects than typical cell phone frequencies.

Plain English Summary

Summary written for general audiences

Pregnant rats exposed to microwave radiation at cell phone and microwave oven frequencies showed concerning effects in offspring. The highest frequency (6000 MHz) caused delayed development, reduced birth weight, and altered brain function, suggesting certain microwave frequencies may affect developing brains.

Why This Matters

This 1997 study provides important early evidence that prenatal microwave exposure can affect brain development, particularly at higher frequencies. What's significant is that these effects occurred at non-thermal exposure levels, meaning the radiation wasn't hot enough to cause tissue heating. The 6000 MHz frequency that showed the clearest effects is higher than typical cell phone frequencies (which operate around 800-2100 MHz), but the neurological changes observed - delayed eye opening, altered maze performance, and modified brain development - suggest the developing nervous system is particularly vulnerable to microwave radiation. The reality is that pregnant women today face multiple sources of RF exposure simultaneously, and this research indicates we should take precautionary measures during pregnancy to minimize unnecessary microwave exposure from devices like cell phones and WiFi routers.

Exposure Details

SAR
10, 20, or 35 W/kg
Source/Device
915 MHz, 2450 MHz, or 6000 MHz

Exposure Context

This study used 10, 20, or 35 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: 10, 20, or 35 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern rangeFCC limit is 0x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 915 MHz - 6 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 915 MHz - 6 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The objective of the investigations presented in this review was to determine if there are adverse effects due to chronic prenatal microwave exposure in rats at term and/or alterations in neonatal and adult offspring psychophysiologic development and growth.

Following the establishment of a nonhyperthermal power density level of microwave radiation, pregnan...

Animals exposed to 915 MHz did not exhibit any consistent significant alterations in any of the abov...

These results indicate that exposure to 6000 MHz radiation at this power density level may result in subtle long-term neurophysiologic alterations. However, in the absence of a hyperthermic state, the microwave frequencies tested, which included frequencies used in cellular phones and microwave ovens, do not induce a consistent, significant increase in reproductive risk as assessed by classical morphologic and postnatal psychophysiologic parameters.

Cite This Study
Jensh RP (1997). Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens? Reprod Toxicol 11(4):601-611, 1997.
Show BibTeX
@article{rp_1997_behavioral_teratologic_studies_using_1046,
  author = {Jensh RP},
  title = {Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens?},
  year = {1997},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/9241682/},
}
PubMed: 9241682

Cited By (52 papers)

View all 52 citing papers on Semantic Scholar

Quick Questions About This Study

A 1997 study found that pregnant rats exposed to cell phone frequencies (915 MHz) showed no significant effects on offspring development or birth outcomes. However, higher microwave frequencies did cause some developmental delays and brain function changes.
Research on microwave oven frequencies (2450 MHz) in pregnant rats found only increased activity levels in offspring, with no other developmental problems. The study suggests microwave oven radiation doesn't significantly increase reproductive risks.
A study exposing pregnant rats to various microwave frequencies found no consistent increase in birth defects or reproductive problems. Only the highest frequency (6000 MHz) caused subtle developmental delays and reduced birth weight.
Research shows certain high-frequency microwaves (6000 MHz) can cause delayed eye opening, altered brain function, and changed behavior patterns in developing offspring. Lower frequencies like those in phones showed minimal brain effects.
Studies indicate most microwave frequencies don't significantly harm fetal development. However, very high frequencies can cause temporary growth delays and subtle nervous system changes, though offspring typically recover normal weight by five weeks.