I think it is more like a 50-meter when you stand in the backyard.
However, according to SDG&E, the electromagnetic is actually pretty ok (high 0.28mg, low 0.1mg and average 0.2mg).
As for the cancer, my family (several generations) live about 50 meters to a POWER STATION (not just a few power lines), and none of us (about 15 people) has cancer related disease. We got high blood pressure and diabete, but no cancer.
So, I guess I should have stronger DNA for this kind of stuff.
Hey, I just realized that there is a High Voltage Power Pole standing right outside of my office (on 3rd floor, exact the same hieght as those power lines), less than 50M.
Oooops… maybe I should get a demotion and have a cubical 😀