animals, the Fe content was slight to moderate (grade 2–3)
(Table 2). Iron content that was slight (grade 2) indicated small Fe
particles that were sparsely distributed in the bone marrow, which
were observed by 100 magnification. Moderate Fe content (grade
3) indicated that many small Fe particles were present in reticulum
cells throughout bone marrow fragments. In several rats administered
60 mg/L Cr(VI), the Fe content was slight to moderate (grade
2–3), in all animals of the highest dose group (180 mg/L Cr(VI)), the
Fe content was slight (grade 2) (Table 2). As shown in Fig. 2, there
were fewer bone marrow macrophages with blue staining (i.e. Fe)
in the 180 mg/L Cr(VI)-treated rat as compared to the control animal.
In contrast, Prussian blue staining of bone marrow from
Cr(VI)-treated mice were unremarkable (data not shown).