That's exactly how I think they are approaching this. Controlled burn.

Edit: I'm reminded about how kings and rulers were often poisoned in earlier times. Napoleon for instance if what I recall reading about his death is true, he was slowly being poisoned with microdoses of arsenic. He became ill and frail and in poor health and then began recovering but finally did a nosedive to death. From what I recall (and its been many years ago that I read about it) they found arsenic in a lock of hair cut from his dead body and preserved till modem analysis methods came to be.

That's exactly how I think they are approaching this. Controlled burn