Fukushima: Wild boars take over Japan's evacuated towns

I don't understand how these boars are eating toxic plants and not getting sick! I am glad they are taking care of the problem. The animals may not be dying from the toxic food sources but they must be getting sick and suffering. I remember reading about the problem before but had no idea it was this bad.

Once they had a discussion about toxic food on TV, and I remember one professor saying that there won't be any effect until there is a large accumulation of radiation. For radioactive spinach, he said one should eat spinach everyday a year to see the effects. But the problem is that it will accumulate and only decay with a half life of 34 years, so better not take chances with the food.