Study Published in British Medical Journal Says No Risk of Early Childhood Cancers & Cell Towers

As a mobile gadget and phone fan, I hope that cell towers do not present any health risk. However, this declaration in Discovery News based on a study published in the British Medical Journal (BMJ).
Study: Cell Phone Towers Don’t Raise Cancer Risk
The conclusion in the published summary is just as assured: here is no association between risk of early childhood cancers and estimates of the mother’s exposure to mobile phone base stations during pregnancy.
Mobile phone base stations and early childhood cancers: case-control study (BMJ 2010;340:c3077)
However, the study was conducted using data from a relatively short period collected a relatively long time ago (1999-2001). While wireless voice technology has not changed in the past decade, the rise of 3G wireless data has. Would this affect the total power output variable that the researchers use? The BMJ summary does not mention the funding source for this project. This, of course, may raise some red flags.