Small amounts of radiation from damaged nuclear plants in Japan have already reached California but they pose no health threats at all. Any radiation that reaches California from Japan is well dissipated by the time it gets there.
Other than Japan most countries haven't been majorly affected by radiation at dangerous levels.
But they are saying that radiation might reach further than Tokyo
When sick people are treated with radiation, that does not make them radioactive. Radiation is dangerous, but radiation patients are not.
Any electromagnetic radiation can be dangerous. Alpha waves are higher on the radiation scale than x-rays so yes, they are dangerous.
The tsunami that hit Japan wiped out the cooling systems for the reactors at the Fukushima Daiichi power plant. The reactors are currently overheating and releasing dangerous amounts of radiation into the atmosphere
If you're asking "Where is Japan on a map of California?" then the answer is: Japan is not on a map of California. If you're asking "Where is Japan in relationship to California" then the answer is: Japan is on the other side of the Pacific Ocean.
Currently, you are far more likely to be hit by lightening twice than to have any issue with the radiation from Japan in any portion of the United States. The background radiation numbers in Tokyo (only 150 miles away from the problem) are roughly the same as we have normally in New York. You will receive more radiation from a window seat in a plane, then you will from this situation.
For many years, there was radiation in the air in Japan from the dropping of atomic bombs on Hiroshima and Nagasaki. However, Japan is perfectly safe to visit today, with no risk of radiation poisoning.
EXTREMLY
It is potentially dangerous. The radiation level found in granite is enough to suppress the immune system, cause birth defects, and cause cancer. There are granite composite options which are not containing the level of radiation that is dangerous.
Radiation is the emission of energy in the form of waves or particles. It can be dangerous because it can damage cells and DNA in the body, leading to health problems such as cancer and radiation sickness.
The bombing of Japan at the end of WWII killed MANY PEOPLE because of the nuclear radiation