The last above ground test was in 1980. Some of it will linger around for decades to come. Cesium-137, for example, has a half life of about thirty years. But, the vast majority has a half life measured in hours or days.
The longer the half life, the less radiation it emits per time. (Or at least that’s what a quick web search says.) So the initially produced radioactive products will emit a ton of radiation per time, but have a short half life and they will quickly become the next element in the series, which will be less radioactive per time but will stick around longer, and then repeat repeat repeat. Each next element it becomes will give off less radiation per time but will be in existence for longer.
It’s not responsible to go into nuance without a lot of preface.
In the natural environment decay is often slowed or hastened based on conditions. And, there’s no human perceptible difference for many half lives: full dose = death; 1/1024th dose = death (1/2^10, 10 half lives).
But, your science is sound in a perfectly sterile environment.
The last above ground test was in 1980. Some of it will linger around for decades to come. Cesium-137, for example, has a half life of about thirty years. But, the vast majority has a half life measured in hours or days.
The longer the half life, the less radiation it emits per time. (Or at least that’s what a quick web search says.) So the initially produced radioactive products will emit a ton of radiation per time, but have a short half life and they will quickly become the next element in the series, which will be less radioactive per time but will stick around longer, and then repeat repeat repeat. Each next element it becomes will give off less radiation per time but will be in existence for longer.
It’s not responsible to go into nuance without a lot of preface.
In the natural environment decay is often slowed or hastened based on conditions. And, there’s no human perceptible difference for many half lives: full dose = death; 1/1024th dose = death (1/2^10, 10 half lives).
But, your science is sound in a perfectly sterile environment.