Spacecraft Water Exposure Guidelines for Selected Contaminants Volume 1 (2004) / Chapter Skim
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Appendix 8: N-Phenyl-beta-naphthylamine
Appendix 8: N-Phenyl-beta-naphthylamine
Pages 290-323
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is a light tan or gray compound produced as flakes or powder. (See Table 8-1 for summary of physical and chemical properties.)
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Commercial grade PBNA in the United States has been reported to contain, as a contaminant, 20-30 milligrams per kilogram (mg/kg) of the human bladder carcinogen betanaphthylamine (BNA)
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Based on the BNA contamination of ingested PBNA, and the amounts of BNA found in the urine samples ofthe volunteers, PBNA was determined to be at least partially metabolized to BNA in humans. Seven of 19 human subjects, six of whom were nonsmokers (BNA is a component oftobacco smoke)
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293 an C)
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294 5 V X an C)
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In the absence of verifiable BNA contamination levels (Laham and Potvin 1 983; Batten and Hathway 1977) , it may be suggested, but not confirmed, that BNA observed in the urine oftested species originated as an impurity in the tested PBNA rather than as an in vivo metabolite.
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Dogs dosed intragastrically with a single dose of ~4C-labeled PBNA at 5 mg/kg demonstrated excretion of >90°/O of the radioactivity from the body within 3 days (~) (Batten and Hathway 1977~.
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( 1982) conducted an in vitro study on the hepatic microsomal metabolism of and macromolecular binding to PBNA in seven mammalian species, including male Sprague-Dawley rats, male B6C3F~ mice, a male rhesus monkey, male Syrian Golden hamsters, a human, a male beagle, and a female pig.
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There is no information available on the specific cytochromes responsible for PBNA metabolism. TABLE 8-5 Relative Rates of Microsomal Metabolism of PBNA by Various Speciesa Species Pig Human Dog Monkey Rat Rate (nmol/min per mg protein)
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were not isoTABLE X-7 Ratio of Principal Metabolites of PBNA Formed in Microsomal Incubations When Pretreated with DPEAa Ratio (6-OH-PBNA/4'-OH-PBNA) Rat Microsomes Control MC-treatedb Human Microsomes 0 0.30 0.25 0.35 0.1 0.43 0.80 0.82 0.5 0.62 1.09 1.04 aPretreated for 3 min.
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3H-PBNA microsomal incubations were examined by HPLC for detection of BNA and its primary hydroxylation product, 2-amino-1-naphthol
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Epidemiological studies of workers in rubber tire factories presented no evidence that occupational exposure to atmospheric PBNA increased incidence of bladder tumors, although inhalation of PBNA mixed with other chemicals was associated with increased incidences of other cancers among workers. No studies have been conducted to determine carcinogenicity of PBNA to humans exposed via oral ingestion.
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. Mortality rates were significant for both male and female rats at the higher doses three of five males and four of five females that received the highest doses died prior to the end ofthe study.
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oral feed study, hematopoietic hypoplasia or atrophy of the femoral bone marrow was seen in 7 of 10 male rats and in ~ of 10 female rats at the maximum doses of PBNA, 6,800 mg/kg and 8,300 mg/kg, respectively (NTP 1988~. Two of 10 females also demonstrated these hematological effects at a dose of 2,800 mg/kg.
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13-wk feed study were observed to have chemical-related nephropathies characterized by renal tubular epithelial degeneration and hyperplasia, with the occurrence of reddish-brown granulated material and degenerating leukocytes within the dilated tubules. The nephropathic lesions occurred at increased incidence and severity in female rats receiving PBNA at 1,200 mg/kg or greater doses.
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Survival rates of dosed mice were comparable to those of controls. Dosed male and female rats had greater survival rates than those ofthe control animals; this was attributed to the lower body weight of dosed rats.
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The absence of carcinogenicity in rats in that study might be related to the limited ability of this species strain to metabolize PBNA to the carcinogen BNA or its carcinogenic metabolites; however, PBNA metabolites were not evaluated in the study (NTP 1988~. Kidney neoplasms observed in both rats and mice were not significantly different from the historical incidence of tumors in NTP studies, with the exception oftwo tubular adenomas found in the high-dose female mice.
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Tumor incidence data revealed a 20% tumor incidence for treated male rats and a 3% incidence for treated female rats. Control animals, which received only arachidis oil, were observed to have a tumor incidences of 60% and 75% for male and female rats, respectively.
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In the NTP (1988) 2-y rodent feed study, ovarian and uterine suppurative inflammation and abscesses of other organs were observed in 15 of 50 female mice given the low dose (450 mg/kg)
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PBNA has been detected in both recIaimed-water and humidity-condensate samples from the Mir space station. The data from Mir-21 are representative of the concentrations that were found at roughly equal intervals over the duration of the mission.
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310 an · _I V]
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314 5 V X al so an C)
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315 Cal ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ X · Cal ~ i ~ .
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for PBNA are those involving oral ingestion via ad libitum feed. This lends some uncertainty to the process of deriving spacecraft water exposure guidelines (SWEGs)
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Nephropathic lesions observed at 1,200 mg/kg in female rats were not seen at the next lower dose of 600 mg/kg, hence a NOAEL of 600 mg/kg was designated. A species extrapolation factor of 10 and a time factor of 1.1 (for extrapolation from 91 d to 100 d)
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318 V ¢ A_ o Cal o V A Cal ¢ x hi v ¢ =O Cal VO .g .O o C)
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feed studies in which F-344N rats were observed to have non-neoplastic kidney lesions at the maximum doses of PBNA, 225 mg/kg for male rats and 261 mg/kg for female rats. Lesions were not observed at the lowest dose of 103 mg/kg in the male species or 11 ~ mg/kg in the female species.
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1979. A comparative study of the chronic effects of magenta, paramagenta, end phenyl-naphthylamine in Syrian golden hamsters.
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1996. Collection and Chemical Analysis of Reclaimed Water and Condensate from the Mir Space Station.
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1962. Carcinogenic and Chronic Toxic Hazards of Aromatic Amines.
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