The data was taken from a sample sealed in a Ziploc Vacuum bag.
The sample was sealed in the vacuum bag to prevent potential radioactive dissipation from off-gassing.
The data was right censored (after 255 minutes) to improve the signal to noise ratio as the decay approached background levels.
The half life was calculated from the exponential trend line fit of the empirical data.
The resultant half life was calculated to be approximately 46 minutes.
Given the probabilistic nature of decay and the trend line fit error, the calculated half life can not be taken as an exact value.
Radioactive decay chains were examined for beta decay isotopes with half lives falling within +/- 20 minutes of the calculated 46 minute half life.
A cursory examination was made of isotope decay chains whose superposition of half lives might approximate a 46 minutes half life.
An examination was made of reported Fukushima fission release products and possible daughters with the requisite half life.
Based on the empirical data analysis and reports of massive releases of I134 (and parent), a strong potential exists that the radioactive fallout contamination sample collected here in Saint Louis Missouri is Iodine 134.
Given the fleeting detectable nature of I134 fallout, and the potential risk to the human thyroid, further vigilance and analysis should be performed by a qualified laboratory.