White blood cell counts, rats exposed

Reductions of approximately 10% in total hemoglobin and mean cell hemoglobin were observed in rats receiving 1,000 mg/kg/day of MIL-H-83282LT for 4 weeks (Mattie et al. 1993). A 47% increase in white blood cell counts was also observed in this study. No effects on hematological parameters were seen in rats similarly exposed to MIL-H-83282 (Mattie et al. 1993). 

Hematological Effects. Hematological effects have not been observed in humans exposed to bromomethane (Johnstone 1945 Kantarjian and Shasheen 1963 Longley and Jones 1965 O Neal 1987 Viner 1945 Wyers 1945). In animals, decreased red and white blood cell counts were noted in one study of rats exposed to 160 ppm (Eustis et al. 1988), but hematological effects were not detected by others (Drew 1984 Haber 1987 Kato et al. 1986 Reuzel et al. 1987). These studies indicate that blood and blood-forming cells are not important target tissues for bromomethane. 

Intermediate exposures to diesel fuel aerosol induced decreases in the mean red blood cell count in rats exposed to a Ct of 8,000 or 12,000 mg hour/m 3 times/week for 3 weeks (Dalbey et al. 1987). However, the statistical significance of this effect was not clearly reported in the study. There was no significant effect on white blood cell count in these rats. Dose-response data were not reported for the individual exposure concentrations used to produce each Ct (see discussion in Section 2.2.1.1). 

A reduction in total white blood cell counts to 60% of control values (p<0.05), but no changes in differential white cell counts or evidence of bone marrow damage, was found in rats intermittently exposed to 700 ppm 2-hexanone after 8 weeks during an 11-week study (Katz et al. 1980). These findings, although inconclusive, suggest that immunological effects may warrant some consideration in future assessments of the potential toxicity of inhalation exposure to 2-hexanone. 

Hematological. Based on a small number of studies, chlorobenzene may cause hematological changes. There were dose and time-related effects on red blood cell parameters, primarily an increase in reticulocyte count which increased in rats but not in rabbits exposed to vapors of chlorobenzene at concentrations > 75 ppm for 24 weeks (Dilley 1977). Other hematological parameters (red blood cell count, hemoglobins, hematocrit, and white blood cell count) were variable and were comparable to controls at the end of the test. Slight leukopenia and... 

Results from hematological evaluations in rats were also equivocal. Hematological evaluations of rats exposed to sodium dichromate at 0.025-0.2 mg chromium(VI)/m3 for 28 or 90 days or 0.1 mg chromium(VI)/m3 for 18 months were unremarkable (Glaser et al. 1985,1986, 1988). However, increased white blood cell counts were found in rats exposed to 0.1 mg chromium(VI)/m3 as sodium dichromate for 30 days and at 0.05 mg chromium(VI)/m3 for 90 days. The white blood cell counts were not increased 30 days postexposure (Glaser et al. 1990). Rats exposed to 0.1 mg chromium/m3 as a 3 2 mixture of chromium(VI) trioxide and chromium(III) oxide for 18 months had increased red and white blood cell counts, hemoglobin content, and hematocrit (Glaser et al. 1986,1988). 

In animal studies, rats exposed to dusts of ammonium diuranate containing 6.8 mg U/m for 6 hours a day, 5 days per week for 30 days developed a rise in neutrophils, a decrease in lymphocytes, a moderate fall in the white blood cell count, and a rise in the number of eosinophils (Dygert 1949b). Rats exposed to airborne uranyl nitrate hexahydrate containing 9.5 mg U/m 8 hours a day, 5 days a week for... 

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