If radiation in the exclusion zone causes less damage than human habitation, what is the argument for maintaining the exclusion zone? Bearing in mind that coal

If radiation in the exclusion zone causes less damage than human habitation, what is the argument for maintaining the exclusion zone? Bearing in mind that coal plants have a lot of negative health effects, so there needs to be an argument that life in the exclusion zone would be detectable worse than life near a coal plant.