biostudies-literatureUnknown9(1)Shuryak IModelling the biokinetics of radionuclide excretion or retention is important in nuclear medicine and following accidental/malicious radioactivity releases. Sums of discrete exponential decay rates are often used, but we hypothesized that continuous probability distributions (CPD) of decay rates can describe the data more parsimoniously and robustly. We tested this hypothesis on diverse human and animal data sets involving various radionuclides (including plutonium, strontium, caesium) measured in the laboratory and in regions contaminated by the Fukushima and Chernobyl nuclear accidents. We used four models on each data set: mono-exponential (ME) with one discrete decay rate, bi-exponential (BE) with two rates, gamma-exponential (GE) with a Gamma distribution of stretched-exponential rateScientific reports1218https://www.ebi.ac.uk/biostudies/studies/S-EPMC6362015biostudies-literatureUsefulness of continuous probability distributions of rates for modelling radionuclide biokinetics in humans and animals.PMC6362015Dadachova EShuryak IfalseUsefulness of continuous probability distributions of rates for modelling radionuclide biokinetics in humans and animals.Modelling the biokinetics of radionuclide excretion or retention is important in nuclear medicine and following accidental/malicious radioactivity releases. Sums of discrete exponential decay rates are often used, but we hypothesized that continuous probability distributions (CPD) of decay rates can describe the data more parsimoniously and robustly. We tested this hypothesis on diverse human and animal data sets involving various radionuclides (including plutonium, strontium, caesium) measured in the laboratory and in regions contaminated by the Fukushima and Chernobyl nuclear accidents. We used four models on each data set: mono-exponential (ME) with one discrete decay rate, bi-exponential (BE) with two rates, gamma-exponential (GE) with a Gamma distribution of stretched-exponential rate2019-01-01T00:00:00Z2019 Feb2026-07-09T12:23:45.666Z2019-03-26T22:50:47ZS-EPMC63620153071877010.1038/s41598-018-38046-9