DYNAMIC CHANGE OF INORGANIC ARSENIC AND METHYLARSENIC COMPOUNDS IN HUMAN URINE AFTER ORAL INTAKE AS ARSENIC TRIOXIDE

Abstract

The outputs of inorganic arsenic compound (As⁺³, As⁺⁵), monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) in the urine were observed with passage of time after oral intake of arsenic trioxide. The subject was completely restricted from the ingestion of seafoods for two days before the experiment and during the urine sampling period, because of high arsenic content of these foods. As⁺³ was excreted in large amounts during the first 12 hours, the outputs corres-ponding to about 12% of the ingested amount, and the outputs of As⁺³ also were greater than those of MMAA and DMAA during the same period. The urinary outputs of arsenic compounds as total arsenic following the ingestion of arsenic trioxide amounted to 40% of the ingested amount during the first 12 hours, and 70% by 72 hours. Under restricted ingestion of seafoods, if the ratios of arsenite to total arsenic increase in the urine of arsenic workers, it is of importance as suggesting an increased absorption of toxic arsenite.