[en] Ingestion and excretion of environmental ⁹⁹Tc was measured in an adult male who ingested 'hijiki' food in his diet that contained a sub-bequerel activity per kg, and which was prepared from a marine alga, Hizikia fusiforme,or hijiki in Japanese, traditionally eaten in the Japanese diet. Harvested hijiki was boiled, dried and cooked. This was eaten at each meal five times over 2 d. All faeces and 24-h urine samples were collected during the 3 d before and subsequent 11 d starting from the day when the intake began. The ingestion intake was measured by analysing the dried hijiki material. ⁹⁹Tc was determined by using liquid-liquid extraction and low-background beta ray spectrometry. The excreta were also analysed for minerals by atomic absorption spectrometry. The apparent absorption rate in the gastrointestinal tract for ⁹⁹Tc under these conditions was calculated to be approximately 0.5. The present result from a single subject indicates the need for further studies. (author)