Health Assessment Document for Diesel Emissions - NSCEP | US ...

1 diesel exhaust on the immune system are needed to clarify the impact of such variables as route
2 of exposure, species, dose, and atopy.
3
4 5.1.2.3.6. Effects on the liver. Meiss et al. (1981) examined alterations in the hepatic
5 parenchyma of hamsters by using thin-section and freeze-fracture histological techniques.
6 Exposures to diesel exhaust were for 7 to 8 h/day, 5 days/week, for 5 moat about 4 or 11 mg/m 3
7 DPM. The livers of the hamsters exposed to both concentrations of diesel exhaust exhibited
8 moderate dilatation of the sinusoids, with activation of the Kupffer cells and slight changes in the .
9 cell nuclei. Fatty deposits were observed in the sinusoids, and small fat droplets were
1 0 occasionally observed in the peripheral hepatocytes. Mitochondria often had a loss of cristae and
11 exhibited a pleomorphic character. Giant microbodies were seen in the hepatocytes, which were
12 moderately enlarged, and gap junctions between hepatocytes exhibited a wide range in structural
13 diversity. The results of this study and others on the effect of exposure of diesel exhaust on the
14 liver oflaboratory animals are summarized in Table 5-9.
15 Green et al. (1983) and Plopper et al. (1983) reported no changes in liver weights of rats
16 exposed to 2 mg/m 3 DPM for 7 h/day, 5 days/week for 52 weeks or of cats exposed to 6 to 12
17 mg/m 3 , 8 h/day, 7 days/week for 124 weeks .
. 18 The use of light and electron microscopy revealed that long-term inhalation of varying
19 high concentrations of diesel exhaust caused numerous alterations to the hepatic parenchyma of
·20 guinea pigs. A less sensitive index ofliver toxicity, increased liver weight, failed to denote an
21 effect of diesel exhaust on the liver of the rat and cat following long-term exposure to diesel
22 exhaust. These results are too limited to understand potential impacts on the liver.
23
24 5.1.2.3.7. Blood and cardiovascular systems. Several studies have evaluated the effects of
25 diesel exhaust exposure on hematological and cardiovascular parameters of laboratory animals.
26 These studies are summarized in nible 5-10. Standard hematological indices of toxicological
27 effects on red and white blood cells failed to denote dramatic and consistent responses.
28 . Erythrocyte (RBC) counts were reported as being unaffected in cats (Pepelko and Peirano, 1983),
29 rats and monkeys (Lewis et al., 1989), guinea pigs and rats (Penney et al., 1981), and rats
30 (Karagianes et al., 1981 ); lowered in rats (Heinrich et al., 1982); and elevated in rats (Research
31 Committee for HERP Studies, 1988; Brightwell et al., 1986). Mean corpuscular volume was
32 significantly increased in monkeys, 69 versus 64 (Lewis et al., 1989), and hamsters (Heinrich et
33 al., 1982) and lowered in rats (Research Committee for HERP Studies, 1988). The only other
34 parameters of erythrocyte status and related events were lowered mean corpuscular hemoglobin
2/1198 5-57 DRAFT--DO NOT CITE OR QUOTE