[ RadSafe ] Global deposition of man made radionuclides

[dcoble at tds.net]

Dear Colleagues,
I am seeking information on the global deposition of anthropogenic radionuclides (e.g., Cs-137, Sr-90, Pu-239, etc.) as a result of releases over the past 14 years. 
The question to answer is; To what extent has releases from North Korea Nuclear weapons testing, Fukushima Daiichi nuclear plant explosion and other nuclear incidents (e.g., WIPP Pu release to atmosphere Feb. 2014) impacted the background concentration of anthropogenic radionuclides on a global or regional scale? 
Any assistance in locating reports or papers will be greatly appreciated. 

Thank you,
Douglas Coble
RRPT, RSO