Cell Phones and Brain Tumors: No Connection?
Study Finds 'No Observable Effect' of Cell Phone Usage on Brain Tumor Incidence
Dec. 3, 2009 -- Scientists say they could find no substantial change in the incidence trend of brain tumors among a study group of 60,000 people five to 10 years after cell phone usage rose sharply in the countries where they lived.
Cell phones have been mentioned for years as possible causes of brain tumors, but the new study, published in the Dec. 3 online issue of the Journal of the National Cancer Institute, found no cell phone-related increase during this study period.
Researchers from Denmark, Finland, Norway, and Sweden say they found that the incidence of brain tumors in the studied population of people from the four countries remained stable, decreased, or showed only a gradual increase that started before the introduction of the wireless devices between 1974 and 2003.
Mobile phone use in those Nordic countries rose dramatically in the mid-1990s, the study says.
Lead author Isabelle Deltour, PhD, of the Institute of Cancer Epidemiology of the Danish Cancer Society, and colleagues say they found no change in incidence trends of brain tumors in data going back to 1998.
They mentioned several possible reasons for their finding:
- The induction period relating cell phone use to brain tumors exceeds five to 10 years;
- The increased risk is too small to be observed;
- The increased risk is restricted to subgroups of brain tumors or cell phone users;
- There is no increased risk of brain cancer by using cell phones.
The authors say they didn’t examine cell phone usage at the individual level during the time period studied, only the incidence of brain tumors.
“Because of the high prevalence of mobile phone exposure in this population and worldwide, longer follow-up trends in brain tumor incidence are warranted,” the authors write.
The U.S. Food and Drug Administration says on its Web site that “The weight of scientific evidence has not linked cell phones with any health problems.”
The agency continues to monitor findings of new and ongoing studies. The federal agency says that wireless phones emit low levels of radiofrequency energy. This is different than radiation from X-rays.