In addition some natural radioisotopes are present.
A recent paper reports the levels of long-lived radioisotopes in the trinitite.
The trinitite was formed from feldspar and quartz which were melted by the heat.
In one kilogram of soil, the potassium-40 amounts to an average 370 Bq of radiation, with a typical range of 100–700 Bq; the others each contribute some 25 Bq, with typical ranges of 10–50 Bq (7–50 Bq for the It is well known that some plants, called hyperaccumulators, are able to absorb and concentrate metals within their tissues; iodine was first isolated from seaweed in France, which suggests that seaweed is an iodine hyperaccumulator.
Synthetic radioisotopes also can be detected in silt.