These maps below are to compare Fukushima and Chernobyl though it’s only about Cs-137.
The important point is, in Chernobyl, it was only in Europe but in Fukushima, it’s the whole pacific ocean.
The US west coast is covered with pale blue, but it means most of the fallout fell into the pacific ocean, from which west coast and continental US rain arises.
Also, when you think about internal exposure, the further the fallout travels, the more risky it becomes.
Why? Because smaller particles fly further, which causes severe internal exposure.
The graph below shows the relationship of the size of the particles and damaged organs.
X axis: size of the particles.
Y axis: % of particles attached to your organ.
胸部(即排出）: taken into the lungs but can get away soon.
口呼吸の場合: When you breathe with your mouth.
胸部（長期）: taken into the lungs and stay long.
鼻部: breathe from nose and particles are attached inside of your nostrils.
Map of ground deposition of caesium-137 for the Fukushima-Daichii accident.
Map of ground deposition of caesium-137 for the Chernobyl accident
Further details can be read from this site.