This article claims that research conducted at the University of Washington provides "proof" that mobile phones cause long-term memory loss:
If true, since long-term memory is believed to involve actual physical changes in neuronal structure (unlike short-term memory), this may suggest that mobile-phone radiation may cause actual brain damage, as in neuronal death. But that is not absolutely indicated.
I did a search at the National Library of Medicine using several key-word parameters and "phones memory" found one study:
Accid Anal Prev 1999 Nov;31(6):617-23
Cognitive load and detection thresholds in car following situations: safety implications for using mobile (cellular) telephones while driving. http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=10487336&form=6&db=m
which is only about how car phones increase the rate of accidents due to taking up too much of one's attention span, not as a result of any brain impairments. I sent an email to the doctor cited in the Mirror article asking for more info. The Mirror article cites other studies, but I did not find them at the NLM using some key key words.