The fission products are generally dispersed over a large area of the globe unless there is local rainfall resulting in localized fallout.
裂变的产物通常将散布在地球表面一片巨大的区域上，除非因为下雨产生局部核尘降。
2
The heaviest fallout would be limited to the area at or downwind from the explosion, and 80 percent of the fallout would occur during the first 24 hours.
受尘降物污染最为严重的地区在爆炸点或者爆炸时的下风方向，80%的尘降物会在爆炸后的24小时内产生。
3
These 85, 000 baby teeth were collected in the late 1950s and early 1960s from children in the st Louis area to study the effects of radioactive fallout in the environment.