The word "recorded" does a huge amount of obscuring work in that sentence.

I thoroughly recommend the book "Voices from Chernobyl: The Oral History of a Nuclear Disaster" by Svetlana Alexievich.

After reading that, a double or triple digit number is simply not credible.

You have yet to address question: why is an oral history compiled by someone with a vested interest in selling copies of her book more (and thus, an incentive to produce a more sensational narrative) more authoritative than the multiple studies conducted by experts in radioactive contamination and it's health effects?

And from what I've been able to determine, this book is responsible for several fabrications promulgated by HBO's Chernobyl, which used this book as one of it's main sources. Among others, the "bridge of death" where supposedly everyone who watched the reactor fire from said bridge died from contamination. In reality, people who were on that bridge are still alive today, and have even been interviewed. Oral history is notoriously unreliable for events steeped in folklore like Chernobyl.

Some of the people interviewed were experts, on the ground. Much of it talks about how much the "official story" omits. How the "authoritative" version isn't. Which was standard Soviet practice. Since you accuse the author (1) of "vested interests", well they cut both ways.

1) https://en.wikipedia.org/wiki/Svetlana_Alexievich

If your reason for trusting on oral history from a private author is distrust incth Soviet Union, you still have to address why this book is more trustworthy than the multitude of of Western studies of the disaster.