A review of the dietary uptake of Th

The available data on inhalation and dietary intake of environmental Th by humans was reviewed. These data, along with reported concentrations of Th in autopsy tissues, were used to estimate the uptake of ingested Th (the f1 factor) from dietary sources. It was concluded that the f1 factor suitable for dietary intake of Th is in the range of 0.001 to 0.01, in contrast to the value of 0.0002 recommended by the International Commission on Radiological Protection for use in occupational exposure situations.