Spacecraft Water Exposure Guidelines for Selected Contaminants Volume 3 (2008) / Chapter Skim
Currently Skimming:
1 Antimony
1 Antimony
Pages 11-44
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 11... ...
Appendix
|
From page 13... ...
Also, numerous semiconductors and electronic equipment that can be found on a spacecraft, as well as materials with flame retardants, may contain antimony. In addition, some future experiments will involve soldering.
|
From page 14... ...
TABLE 1-1 Physical and Chemical Properties of Antimony and Two Soluble Antimony Compounds Antimony Potassium Antimony Parameter Metallic Antimony Tartrate⋅3H2O Trichloride Chemical formula Sb C8H4K2O12Sb2⋅3H2O SbCl3 Valence Sb(III)
|
From page 15... ...
for antimony compounds in drinking water is the main purpose of this document, descriptions of adverse effects and discussions are limited to soluble antimony compounds and studies dealing with ingestion of such compounds. Although the exact form of the soluble compound in spacecraft drinking water is not known at this time, it is not expected that insoluble forms of antimony will be found in the water.
|
From page 16... ...
when estimating exposure from the GI tract. Distribution No data are available on the tissue distribution of antimony in humans who ingested antimony compounds orally.
|
From page 17... ...
TOXICITY SUMMARY Numerous toxicity studies have been conducted in animals using relatively insoluble antimony oxides (Fleming 1938; Gross et al.
|
From page 18... ...
, although the oral LD50 for APT (the soluble salt of antimony) for rats is 115 mg/kg, the LD50 for Sb2O3 is 20,000 mg/kg, showing a vast difference between soluble and relatively insoluble forms of antimony compounds.
|
From page 19... ...
For the 14-d drinking-water protocol, doses estimated from water consumption data were 0, 16, 28, 59, 94, or 168 mg/kg in rats and 0, 59, 98, 174, 273, or 407 mg/kg in mice. Antimony concentrations in the blood, kidney, heart, liver, and spleen of rats and mice were measured at the end of the study.
|
From page 20... ...
for 13 wk. An additional 10 male and 10 female rats were included in each of the control and 500ppm groups and were given tap water for a further 4 wk as a recovery period after the 13-wk treatment period was completed.
|
From page 21... ...
Male rats from the 500-ppm dose group had decreased red blood cell and platelet counts and a slightly increased mean corpuscular volume. No treatment-related changes in total thyroid hormone, thyroxin, were reported.
|
From page 22... ...
toxicity study in which antimony, as APT, was administered in the drinking water at concentrations of 0 or 5 ppm to groups of 50 male and female Long-Evans rats from weaning to death. The antimony dose can be estimated to be 0.43 mg/kg/d based on a nominal rat body weight of 350 g and water consumption of 30 mL/d.
|
From page 23... ...
Body weight was measured weekly for the first 6 wk and monthly thereafter. Serum glucose was measured on days 718 and 698 for control male and female rats, respectively, but it was measured on days 853 and 859 for treated male and female rats.
|
From page 24... ...
(1991) studied the genotoxicity of some antimony compounds in the bacterial DNA repair (rec)
|
From page 25... ...
Similarly, no robust animal studies indicate that antimony compounds are carcinogenic by the oral route. The only lifetime studies were conducted by Kanisawa and Schroeder (1969)
|
From page 26... ...
Toxicity studies conducted after administration of various antimony compounds via oral route have been summarized in Table 1-2. RATIONALE The following paragraphs provide a rationale for proposing 1-, 10-, 100-, and 1,000-d SWEG values for soluble antimony in NASA's spacecraft water.
|
From page 27... ...
A woman consumed an unknown 1991 amount and concentration of antimony trisulfide Antimony potassium Dog Vomiting Houpt et al. tartrate Gavage 1984 One dose of 13.2 mg/kg/d Antimony potassium Rat Decreased survival; minimum lethal dose Bradley and tartrate Gavage Frederick 1941 One dose of 300 mg/kg/d (Continued)
|
From page 28... ...
1998 tartrate Drinking water (0.5, 5, 50, and 500 in females; 30% less water consumption in 500-ppm group; ppm) depression in weight gain in males and females; increase in Calculated doses: the kidney-to-body weight ratio; decreased red blood cell 0.06, 0.56, 5.58, and 42.17 mg of and platelet counts and slightly increased mean corpuscular Sb/kg/d (M)
|
From page 29... ...
tartrate (M, F; 50/sex) ; 5 ppm as APT in males; decreased nonfasting serum glucose; median life span 1970 drinking water of treated males and females was about 106 d less than that of controls; significant reduction in LT90 especially in fe males; no treatment-related tumor incidence; epidemic of virulent pneumonia struck the rat colony Abbreviations: APT = antimony potassium tartrate; EEG = electroencephalogram; F = female; LOAEL = lowest-observed-adverse-effect level; LT90 = 90% lethal time; M = male.
|
From page 30... ...
These are based on estimated water consumption of 2.8 L/d and an average adult body weight of 70 kg. the results of the Schroeder study, as well as the existing antimony toxicity database available for deriving RfD, as low.
|
From page 31... ...
; EPA, U.S. Environmental Protection Agency; IARC, International Agency for Research on Cancer; Group D, not classifiable as to human carcinogenicity; Group 2B, possibly carcinogenic to humans; Group 3, not classifiable as to carcinogenicity in humans; MCL, maximum contaminant level; MCLG, maximum contaminant level goal; RfD, oral reference dose.
|
From page 32... ...
The authors reported on four adults who ingested cake mistakenly made with tartar emetic instead of cream of tartar and had severe abdominal cramps, nausea, continuous vomiting, and watery diarrhea. Moderate leukocytosis and hemoconcentration and decreased extracellular volume were noted.
|
From page 33... ...
NASA has not done taste tests on antimony in water. The levels derived will not affect the water consumption, as we already used a spaceflight factor for that risk, thus offering some margin of safety for taste.
|
From page 34... ...
Also in the 500-ppm male rats, a decrease in red blood cells and an increase in mean corpuscular volume were noted, indicating hematologic effects, but the NOAEL of these effects was 50 ppm. A statistically significant decrease in the platelet counts of 500-ppm-dosed males was also noted.
|
From page 35... ...
Giving 500 ppm APT in drinking water to male rats resulted in a statistically significant reduction in the number of red blood cells, a reduction in mean corpuscular volume (average volume of a red blood cell) , and a reduction in platelet counts.
|
From page 36... ...
The statistician from the NRC SEG committee recommended that NASA use the data from the power model, which would provide a more appropriate model fit of the response. Figure 1-1 shows the BMD plots of two doseresponse models for changes in red blood cells due to antimony ingestion.
|
From page 37... ...
Abbreviations: BMD, benchmark dose; BMDL, 95% lower confidence limit of BMD. The 100-d AC can be calculated using the statistically significant decrease in the amount of red blood cells as a critical end point in male rats ingesting 500 ppm of APT via drinking water (Poon et al.
|
From page 38... ...
(1970) stated that male and female rats in control and treated groups had a high incidence of death due to an epidemic of virulent pneumonia that struck the rat colony during the 4 years of the experiment.
|
From page 39... ...
In the absence of any other chronic toxicity study on soluble antimony compounds by the oral route, 1,000-d AC will use the observations of hematologic effects reported by Poon et al.
|
From page 40... ...
Abbreviations: BMDL, 95% lower confidence limit on the benchmark dose; LOAEL, lowest-observed-adverse-effect level; NA, not applicable; NOAEL, no-observed-adverse-effect level; RBC, red blood cell; -- , not derived for this duration.
|
From page 41... ...
1992. Subacute toxicity of pentavalent antimony compounds in rats.
|
From page 42... ...
1992a. Comparison of the clastogenic effects of antimony trioxide on mice in vivo following acute and chronic exposure.
|
From page 43... ...
2000b. Methods for Developing Spacecraft Water Exposure Guidelines.
|
From page 44... ...
44 Spacecraft Water Exposure Guidelines mony, gold, and platinum: III. Antimony.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.