The rapid increase in cell phone use during the last decade has raised many safety concerns. In particular, the risk for vestibular schwannoma is associated with mobile phone use because the acoustic nerve tissue is a sound perception organ and is located close to where people hold their mobile phones during use.
A few epidemiology studies have reported higher rates of tumors inside the skulls of people who use cell phones heavily for a period of 10 years or more. Of particular concern are benign Schwann cell tumors called acoustic neuromas, which affect nerve cells connecting the inner ear with structures inside the brain. These growths can in some instances progress to malignant cancer with time.
In a study posted to the U.S. National Institutes of Health’s National Library of Medicine, 119 patients who had undergone surgical tumor removal were evaluated. The amount of mobile phone use according to duration, daily amount, and cumulative hours were compared between two groups; first, a case-control study for the association of mobile phone use and incidence of vestibular schwannomas was conducted. Both cases and controls were investigated with questions based on guidelines from INTERPHONE, which was a study conducted by the International Agency for Research on Cancer in thirteen different countries, at a cost of $24 million.
The location and volume of the tumors were investigated by MRI. The study found that tumors may coincide with the ear most frequently used by the person when using their cell phone, and that tumor volume showed a strong correlation with the amount of mobile phone use.
Study Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907669/
Cellular telephone use and risk of acoustic neuroma:
https://www.ncbi.nlm.nih.gov/pubmed/14742288
Epidemiologic evidence on mobile phones and tumor risk:
https://www.ncbi.nlm.nih.gov/pubmed/19593153
Handheld cellular telephones and risk of acoustic neuroma:https://www.ncbi.nlm.nih.gov/pubmed/11971109