6,486 Studies Reviewed. 85.2% of Original Studies Found Biological Effects. The Evidence is Clear.
Shield Your Body

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

Cancer & Tumors

GSM and DCS wireless communication signals: combined chronic toxicity/carcinogenicity study in the Wistar Rat.

No Effects Found

Smith P, Kuster N, Ebert S, Chevalier HJ · 2007

View Original Abstract
Share:

This major 2-year rat study found no cancer increase from daily cell phone radiation exposure, even at levels 8 times higher than phone safety limits.

Plain English Summary

Summary written for general audiences

Researchers exposed 1,170 rats to cell phone radiation (GSM and DCS signals) for 2 hours daily, 5 days a week for up to 2 years to test whether this exposure causes cancer. They found no increase in tumors or cancer rates compared to unexposed control rats, even at the highest radiation levels tested. This large, long-term study suggests that chronic exposure to these specific wireless signals at the tested levels does not increase cancer risk in rats.

Why This Matters

This study represents one of the largest and longest animal studies examining wireless radiation and cancer risk, involving over 1,000 rats exposed for nearly their entire lifespan. The exposure levels ranged from 0.44 to 4.0 W/kg SAR, with the highest level being roughly 8 times higher than current cell phone safety limits (0.5 W/kg in Europe). What makes this research particularly relevant is that it tested the actual GSM and DCS signals used by cell phones, not just generic radiofrequency radiation. The negative findings add to a complex body of evidence on wireless radiation and cancer. However, the reality is that animal studies don't always translate directly to human health outcomes, and this single study doesn't resolve the ongoing scientific debate about long-term wireless radiation exposure and cancer risk.

Exposure Details

SAR
0.44, 1.33 and 4.0 W/kg
Exposure Duration
2 h/day, 5 days/ week for up to 104 weeks

Exposure Context

This study used 0.44, 1.33 and 4.0 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: 0.44, 1.33 and 4.0 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 4 times higher than this level

Study Details

To study the effects of GSM and DCS wireless communication signals on carcinogenicity in rats.

A total of 1170 rats comprised of 65 male and 65 female Han Wistar rats per group were exposed for 2...

There was no adverse response to the wireless communication signals. In particular, there were no si...

Cite This Study
Smith P, Kuster N, Ebert S, Chevalier HJ (2007). GSM and DCS wireless communication signals: combined chronic toxicity/carcinogenicity study in the Wistar Rat. Radiat Res. 168(4):480-492, 2007.
Show BibTeX
@article{p_2007_gsm_and_dcs_wireless_3405,
  author = {Smith P and Kuster N and Ebert S and Chevalier HJ},
  title = {GSM and DCS wireless communication signals: combined chronic toxicity/carcinogenicity study in the Wistar Rat.},
  year = {2007},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/17903030/},
}
PubMed: 17903030

Cited By (39 papers)

Quick Questions About This Study

No, a 2007 study exposing 1,170 rats to GSM and DCS cell phone radiation for 2 hours daily over 2 years found no increase in cancer rates. Even at the highest radiation levels tested, tumor incidence remained the same as unexposed control rats.
A comprehensive 2-year rat study found DCS wireless communication signals caused no adverse health effects during chronic exposure. Researchers detected no significant differences in tumor development, cancer rates, or survival between exposed and unexposed animals across 1,170 test subjects.
Research indicates GSM frequencies do not increase tumor development. A large-scale study exposing rats to GSM signals for up to 2 years found no significant differences in primary tumor incidence, tumor multiplicity, or cancer progression compared to control groups.
No, wireless communication signals did not cause metastases in a major animal study. Researchers found no significant differences in the number of rats developing metastases between those exposed to GSM and DCS signals versus unexposed controls over a 2-year period.
A study using 5-day weekly exposure schedules found no harmful effects from cell phone radiation. Rats exposed to GSM and DCS signals for 2 hours daily, 5 days weekly for 2 years showed no increased cancer risk or adverse health outcomes.