Cell Phones and Cancer
First, an apology for the last couple of abbreviated blogs. I have been in California, with my iPad, over the last week, and clearly there is a steep learning curve (of which I am maybe half way up) re how to use it. Sometimes, I could just not make it work as I wished.
This is a report from the American Cancer society about a very large study looking at the association of cell phone use and malignant brain tumors. The good news is that none was found.
A large new study finds no link between long-term use of mobile phones and brain or central nervous system cancer. The research appears on bmj.com. In what is described as the largest study on the subject to date, Danish researchers found no evidence that the risk of brain tumors was raised among more than 350,000 mobile phone subscribers over an 18-year period. A nationwide Danish study is the only cohort study investigating mobile phone use and cancer to date. It has compared cancer risk of all 420,095 Danish mobile phone subscribers from 1982 until 1995, with the corresponding risk in the rest of the adult population with follow-up to 1996 and then 2002. The study had so far found no evidence of any increased risk of brain or nervous system tumors or any cancer among mobile phone subscribers. For the current report, researchers looked at evidence up to 2007. The massive study looked at data on the entire Danish born population aged 30 and over. Their analysis found those with the longest mobile phone use - 13 years or more - had cancer rates that were almost the same as non-subscribers of mobile phones. They conclude use of mobile phones for 10 years or more was not associated with higher risks of cancer, but that associations with use longer than 10-15 years cannot be ruled out. Below are comments from Elizabeth Ward, PhD, American Cancer Society National vice president for intramural research, in response to the report.
"The large Danish study of mobile phone subscribers adds to the body of evidence regarding cell phone use and brain cancer. The study found no increased risk of central nervous system tumors among mobile phone subscribers compared to the general population. The strengths of this study include its large size (358,403 telephone subscribers), ascertainment of cell phone "exposure" from mobile phone subscription records rather than participant recall and ascertainment of brain tumor cases from a very complete national cancer registry. The most significant weakness of the study is that subscription to a mobile telephone does not necessary indicate exposure (for example, one family member may subscribe to a cell phone that other family members use) and there is no data on frequency or duration of use. Other limitations of the study include a maximum duration of exposure it fifteen years, does not address potential effects among children, and did not address parotid gland tumors which have been suggested as caused by cell phones.
"The authors of the study acknowledge that miss classification of exposure may have biased their study towards a negative finding, but conclude that the results can be used to rule out moderate to large risks associated with mobile phone use.
"The bottom line is that, at this point, there is not strong evidence for an association between cell phone use and cancer in humans. This study will not quell all concerns about this issue. However, those who are concerned about this electromagnetic field exposure can reduce it by using earpieces. In addition, it is important for the public to be aware that the primary documented risk of cell phones continues to be their association with vehicle accidents. "
For more information, please see Cellular Phones on www.cancer.org