Is it safe to go to Japan to teach english at the moment?

Question:

i'm afraid of the radiation - in the air and in the fish and other foods.

Answer:

Yes, it is. The only problem area is about 20 km around the Fukushima nuke plant. There's been some worry about cows that had been fed contaminated hay, but I believe it will be recalled and destroyed.
I wouldn't worry. Most of Japan is fine.