[u320]

Because society does not accept the answer "we really don't know" in cases of public health.

[TheRealPomax]

Except it's not "we really don't know", it's "after looking at thousands upon thousands of cases over many decades, there do not appear to be any statistically relevant effects".

[u320]

That gives us an upper bound but the real answer could be anything between that and harmless.

So I mean "we don't know" as in "we don't have the complete answer".

[pfdietz]

From this specific accident. However, the evidence from radiation biology in general is that there should be a certain number of cancers (and no, don't feed me anti-LNT BS.)