Living close to a mobile phone mast does not increase the chance of a pregnant woman's baby developing cancer before he or she reaches the age of five, a study has found.
Researchers from Imperial College London looked at almost 7,000 children and found those who developed cancer aged four or younger were no more likely to have a birth address close to a mast than their peers.
The study included 1,397 British children aged up to four who were registered with leukaemia or a tumour in the brain or central nervous system between 1999 and 2001.
The proximity of their birth address to a mast was compared to that of four healthy children of the same gender who were born on the same day, chosen randomly to act as controls.
Professor Paul Elliott, director of the MRC-HPA Centre for Environment and Health at Imperial College London and the study's lead author, said: "People are worried that living near a mobile phone mast might affect their children's health.
"We looked at this question with respect to risk of cancers in young children. We found no pattern to suggest that the children of mums living near a base station during pregnancy had a greater risk of developing cancer than those who lived elsewhere."
The study, published on the website of the BMJ medical journal, is the largest of its kind and was funded by the Mobile Telecommunications and Health Research programme.
Researchers only considered the address the mother was living at when the baby was born as information on any previous or subsequent addresses was not available.
The information came from national registers and researchers did not have individual contact with families.
Prof Elliott is principal investigator for the UK arm of the cohort study on mobile communications, which launched in April 2010 and will run for 20 to 30 years, following the health of around 250,000 participants in five European countries.