Line 1757 Dose coefficients for 40K.
The validity of these conversion coefficients for 40K is limited, since they only apply to potassium with artificially enhanced 40K-content or to small intakes of natural potassium. For higher intakes of natural potassium (more than, say, 300 Bq or 10 gK) the excess potassium is excreted within several hours (see ref. below). This is due to the homeostatic control of the potassium concentration in blood. In that case the conversion coefficient is at least two orders of magnitude smaller (30 days vs 1 h) than the values given in the table.