This background document is the 2003 assessment behind the WHO drinking-water guideline for antimony. It derives a tolerable daily intake from a 90-day rat drinking-water study of potassium antimony tartrate and states the guideline arithmetic. It also prints occurrence and absorption figures that are not the same sentences as the two-page chemical fact sheet.
Key numbers
The suggested NOAEL, following Lynch et al. 1999 on the Poon et al. 1998 study, is 6.0 mg/kg body weight per day, based on decreased body-weight gain and reduced food and water intake (PDF p.17, printed p.9). A TDI of 6 µg/kg body weight uses an uncertainty factor of 1000 (100 for intra- and interspecies variation and 10 for the subchronic study). The guideline value of 20 µg/litre is described as a rounded figure for a 60 kg adult drinking 2 litres per day with 10 percent of the TDI allocated to drinking water (PDF p.18, printed p.10). The same pages say the value could be highly conservative. Groundwater and surface water are printed as normally 0.1 to 0.2 µg/litre, and drinking water as appearing to be less than 5 µg/litre (PDF p.11, printed p.3). Gastrointestinal absorption is printed as 5 to 20 percent in animals and 5 percent in four people after involuntary acute intoxication with antimony potassium tartrate. An oral LD50 for antimony trioxide is printed as greater than 20,000 mg/kg body weight. IARC 1989 is cited as Group 2B for antimony trioxide and Group 3 for antimony trisulfide.
Methods (brief)
The document is a guideline background review, not a new survey. The critical study is the Poon et al. 1998 drinking-water study as re-read by Lynch et al. 1999. Those two papers were not re-opened for this source page.
Evidence fitness
The page supports the 2003 oral TDI, the 20 µg/L guideline arithmetic, and the background document’s own occurrence and absorption sentences. It does not support a dermal dose, an infant-specific TDI, or a claim that the fact sheet’s groundwater line (less than 0.001 µg/L) is printed here.
Limitations
Assessment date 2003. The 2023 IARC classification is later than the Group 2B sentence in this document. Oral LD50 and absorption figures are not averaged with ATSDR or ICRP values.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.