If you live in Riverside California, on March 15th you inhaled a combined 25,740,000 atoms of Plutonium 238 and Plutonium 239.
The source data is from EPA's RADNET. The data indicates 0.0000013 pCi per cubic meter of Plutonium 238 was detected in an air filter from Riverside California. The data had a standard deviation of 0.000003.
(Based on NIST definitions, the sigma EPA listed may not have been actually calculated from the sample) The exact same quantity of Plutonium 239 was also detected.
In order to quantify what that fallout means on the individual level, I decided to calculate approximately how many atoms of Plutonium a person in Riverside California would have inhaled on that Tuesday. To perform that analysis I had to make the following PRIMARY assumptions:
(1) the air sample was taken over 3/11 to 3/15, but all contamination occurred on 3/15
(2) 1 pCi = 2.2 disintegration per minute (DPM)
(3) 1 DPM = 12,500,000,000 Plutonium atoms
(4) A person breathes 3 cubic meters per hour
(5) A person was exposed for only 24 hours
On the bright side of things, atoms are VERY small.
A big hat tip to Alexander Higgins Blog for the heads up on how to find the Plutonium data.