interstate·4 ปีที่แล้ว·discussThis report might be of use:https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/canj...
interstate·4 ปีที่แล้ว·discussOne possibility: Operation Plumbbob, a series of open air nuclear tests in 1957, generated considerable fallout in north central NE.
https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/canj...