In spite of the general toxicity, ecotoxicity and sparsely known metabolism of silver, WHO allows silver ions (Ag) up to 0.1 mg/l in drinking water disinfection. In order to determine the accumulation and distribution of silver in a mammalian body, mice were given for 1 and 2 weeks drinking water containing a 3-fold lower concentration, namely 0.03 mg/l silver ions as silver nitrate labelled with Ag-110m. The silver concentrations in different tissues were analysed by gamma radioactivity. The saturation of tissues with silver seems to occur quickly, as there were no statistical differences between silver contents of mice tissues in spite of the study design that mice were administered silver for 1 or 2 weeks. The highest concentrations were found in musculus soleus (m. soleus), cerebellum, spleen, duodenum, and myocardial muscle in the rank order. Concentrations of silver in musculus gastrocnemius (m. gastrocnemius) were found to correlate negatively with cerebrum and positively with blood and kidneys. The accumulation of silver into organs and tissues important in motor functions may be of relevance especially in emergency and catastrophe situations in which accurate motor functions may be critical. A re-evaluation of the present recommendations on the use of silver salts for disinfection of drinking water might be necessary. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.