well the main difference seems to be that some crew in stalker stated they had the sense of being poisoned in that dust and fume cloud and also developed accute allergic reactions. Its still all just based on the statements of the sound technician, i did not find interviews with other crew that said the same, but i'm sure there are some interview transcriptions in russian print somewhere. In the end the best source would probably be the estonian death statistics for cancer increases closer to those areas or further downstream the same river.