Acoustic neuroma is a non-malignant tumor that develops on the main nerve leading from the inner ear to the brain.

If it is slow-growing, it can cause unsteadiness, ringing in one’s ear and hearing loss. If it grows rapidly, or large enough to press against the brain, it can interfere with vital functions.

The World Health Organization, International Agency for Research on Cancer, and the Hardell studies in Sweden previously linked long-term cellphone use with acoustic neuroma and, last fall, the Italian Supreme Court ruled in favor of the connection between cellphone use and acoustic neuroma.

This month, a study of 790,000 women in the United Kingdom shows that women who used a cellphone were 2.5 times more likely to have an acoustic neuroma than those who never used a cellphone. The risk increased with the number of years of use.

The authors of the study, affiliated with the University of Oxford, recruited the women before they developed the tumor. They were asked how long they had used a cellphone: never; less than once a day; or, every day. Those who used a cellphone were asked how long.

Over the years, I have collected thousands of radio frequency studies. Every one of them has at least one flaw.

My opinion, as a radio frequency consultant, is that this latest one most likely underestimated the long-term risk because the women only were followed for seven years, and tumors can take decades to develop.