This English summary reports the Food Safety Commission of Japan risk assessment of hexavalent chromium, carried out for an amendment of beverage standards by the Ministry of Health, Labour and Welfare. The commission judged hexavalent chromium carcinogenic in rodents by drinking water, set a tolerable daily intake from a mouse duodenal lesion, and estimated intake only from mineral and tap water because chromium in food is regarded as trivalent.
Key numbers
- Tolerable daily intake: 1.1 µg/kg bw/day for hexavalent chromium, from a BMDL10 of 0.11 mg/kg bw/day for diffuse epithelial hyperplasia in the duodenum of male mice in a two-year drinking-water study, with an uncertainty factor of 100 (summary, p. 56; p. 57).
- Estimated intake of hexavalent chromium from mineral water and tap water: mean ca. 0.04 µg/kg bw/day and high 0.290 µg/kg bw/day, both below the tolerable daily intake (summary, p. 56; p. 57).
- Transgenic mutation assays showed no significant increase in mutant frequency in target tissues after 28 days (rats) or 90 days (mice) of drinking-water exposure (summary, p. 56).
Methods (brief)
Weight-of-evidence review of absorption, distribution, metabolism and excretion, acute to chronic toxicity, carcinogenicity, reproductive and developmental toxicity, genotoxicity, epidemiology and exposure data from published articles and international evaluation reports; benchmark dose modeling of the two-year mouse drinking-water study.
Evidence fitness
Supports statements on the oral toxicology of hexavalent chromium, its tolerable daily intake as set by this commission, and drinking-water intake estimates in Japan. It does not provide food concentration data, because it assumes food chromium is trivalent.
Limitations
Two-page English excerpt of a longer Japanese report; only the Japanese text has legal effect. The intake estimate covers water only and its population and data sources are not detailed in the excerpt.
Related evidence
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