Model results of kidney burdens from uranium intakes

Uranium is a naturally occurring element, which is both radiologically and chemically toxic. When dealing with intakes of uranium, whether natural or depleted, chemical toxicity to the kidney usually predominates over radiological toxicity. This is especially true for uranium compounds in soluble (inhalation Type F) and moderately soluble (inhalation Type M) forms. To assess chemical toxicity, information on kidney burden per unit intake is required. This study summarizes the kidney burdens per unit intake for common exposures from uranium ingestion and inhalation. ICRP models developed for radiation dosimetry purposes can equally well be used to estimate kidney burdens from uranium intakes. While dosimetric quantities and data are tabulated in ICRP publications, data on uranium burdens in kidney are not explicitly given in these tabulations. In this work, the most recent ICRP models were utilized to generate a compilation of kidney burdens from common intakes. Calculations were made for four age groups from infant to adult. For all age groups, long-term chronic uranium ingestion will result in a kidney burden of 6.6% of daily uranium intake. Comparisons of kidney burdens due to acute ingestion and acute inhalation show that inhaled uranium compounds of Type F and Type M will generally result in higher burdens to kidney compared to the same amount of uranium compounds ingested.