The problem with radiation for humans is, that humans live far longer than most species - at least common to the two regions with a reactor blowup. An e.g. 10 year loss of projected lifespan would be considered unacceptable for a human population, but most animals don't live long enough to get significantly impacted.
What about them? By the way the article is about people living outside the exclusion zone, though at its borders. Only about 150 humans are currently living illegally inside the zone, according to the article. And of course, they are not dying immediately, but certainly have a larger risk for cancers. Though, if they don't smoke and as they are not exposed to many other contaminants, it might not be too bad.
