The Russian scientists and firefighters who fought the Chernobyl fire reported a “metallic taste” in their mouth. That taste was from radioactive iodine. (It is well known that all iodine has a metallic taste.)
For example, Colonel Grebeniouk – who led the Russian troops in charge of controlling the situation – said:
[youtube http://www.youtube.com/watch?v=yiCXb1Nhd1o]There is substantial evidence of ongoing nuclear chain reactions. Another piece of evidence – as pointed out by nuclear expert Arnie Gundersen – is that there are widespread anecdotal reports of people in Japan and the West Coast of the United States reporting a metallic taste in their mouths: [vimeo http://www.vimeo.com/25002205 w=400&h=225]
There was a metallic taste in our mouths, an acidity. They say radiation has no taste. It was only later we realized it was the taste of radioactive iodine.
Note 1: Iodine 131 decays to xenon 131, a non-radioactive form of xenon. Therefore, it is unlikely that a non-radioactive form of iodine would be in the air.
Note 2: There are, of course, other sources of “metallic tastes”.