At 05:16 PM 3/18/2011, Mike S wrote:
If that were true, everyone on the left coast will soon be dead. I'm
>pretty sure the units are microrads/hr, which is only a million times
>lower.

Yes, they specify that it's microrads/hr for Cesium 137 and Cobalt 60.

They also point out that the difference between readings of 4 and 28
are statistically meaningless variations from a nominal 16, that is
it's impossible to say whether three readings individual readings
with those numbers actually represent different amounts of radiation.

But as they say, it's a good place to point people to show them that
the background radiation in the US is absolutely completely totally
normal, as is the other site Rob mentioned.  It will certainly be
interesting to watch over the next few days to see whether any rise
is detectable.

Yours,
David