New research has shown that males who talk for hours on cellphones may damage their sperm and thus their chances of fathering a baby.
An experiment on semen revealed evidence of DNA damage after 16 hours of exposure to radiation similar to the output of a mobile phone.
To reach the conclusion, researchers at the University of Newcastle built a device to irradiate sperm at the same radio frequency as mobile telephone calls.
"After 16 hours exposure, there was clear evidence of DNA damage," News.com.au quoted Prof Aitken, as saying.
"This is a very early finding from our analysis, but it does raise concerns," the expert added.
DNA damage in spermatozoa has been associated with decreased fertility, increased risk of miscarriage and various kinds of disease in offspring, including childhood cancer, and a number of neurological disorders such as autism, bipolar disorder and spontaneous schizophrenia.
In the study, damage was caused by oxidative stress - when the generation of free radicals exceeds the body's own anti-oxidant defence mechanisms.
Prof Aitken said it was well known that sperm DNA fragmentation was predominantly triggered by oxidative stress which may arise from infection, smoking or older age, but there had been little research about the link with mobile phones.
Unsaturated fatty acids in foods such as margarine were also known to trigger free radicals and potential oxidative stress, he said.