Hemotoxic effects of a dermally applied coal coprocessing product in the rat

The present study was conducted as part of a larger project to determine the toxicity of dermally applied coal coprocessing products. Groups of male and female rats were administered, dermally, heavy gas oil II (HGOII) at 8.7, 20.8, 50.0 and 120 mg kg(-1) body wt, day(-1) for 91 days. A coal liquefaction product was given as positive control at 120 mg kg(-1) body wt. day(-1). Saline was used on control animals. At termination, the blood and bone marrow were taken from the animals and subjected to hematological examination. Dose-dependent hematological effects were seen in peripheral blood in HGOII-treated animals and consisted of significantly reduced hemoglobin, hematocrit, red cell count and platelet count. Mean corpuscular volume was increased, along with mean corpuscular hemoglobin, at the highest dose level. Red cell protoporphyrin, total iron and total iron binding capacity were also significantly elevated at this dose level. Morphological analysis of blood showed increases in polychromatic red cells, schizocytes, Howell-Jolly bodies, injured cells, hypersegmented neutrophils and shift platelets primarily at the highest dose level. In addition, there was notable anisocytosis, microcytosis and macrocytosis. Quantitative bone marrow evaluation revealed a significant reduction in the myeloid/erythroid ratio for the three highest treatment levels of HGOII. These data indicate that the effect of HGOII on the hemopoietic system is a treatment-related, partially compensated, hemolytic anemia. The apparent reduction in myelopoiesis may be compensated for by a concurrent increase in marrow volume.