Reading through the news tonight, and found this story on the BBC:
Pylons 'may be a leukaemia risk'
It sounds like there might be some risk in living near pylons, but, like other studies, it'll need further investigation. What does seem to be true though, is the influence of low-level magnetic fields.
Reading Ivan Nobles new book, I grabbed a copy this morning, he also commented on the links between mobile phones and brain tumours. It also seems to be inconclusive, but, as pointed out, we're only going to see the impact of mobiles now. It's not a new influence on life, and rather concerningly, it seems my age group is going to be the first measure of whether it has impacted.