Chromatographic chemical characterization of solvent refined coal I and II liquids for toxicological testing

Toxicology of coal liquefaction products: an overview

Repeated exposure to coal liquefaction products produces a broad range of systemic effects. Among these, growth suppression, anaemia, leucocytosis and other haematological disorders are most prominent. Bone marrow, liver and kidney are the target organs affected by treatment. The effects are more severe with heavy distillates and male rats are more sensitive than females. Other changes included increased serum transaminases, alkaline phosphatase and cholesterol. Depending on the route of administration, the skin or lung may also be affected. Inhalation exposure produces the most severe changes, and oral exposure the least. Distillates containing N-PAHs and sulphur-containing PAHs are also more biologically active. Teratological effects were only observed if animals were exposed to the heavy distillate. Similarly, heavy distillates have mutagenic or carcinogenic properties. Teratological effects, as well as mutagenicity and carcinogenicity, of the coal liquefaction distillates seem to be linked to their PAH content, especially the N-PAHs. From the data presented in this review, it should become evident that the potential effects of coal liquefaction products on human health could be severe, especially with long-term exposure. Limited information exists on the occupational effects to coal liquefaction materials because most of the work to date has been with pilot plants. Careful and good judgement is required in order to extrapolate data from pilot plants to commercial-scale production. Experience in health effects of workers in the petroleum industry and coke-oven operations can serve as a guide for the implementation of industrial hygiene programmes for coal liquefaction operations. These programmes include engineering controls, health education, personal monitoring and hygienic practices, medical surveillance and long-term epidemiology studies, and they should be implemented to make coal liquefaction a healthy and environmentally sustainable industry.

Induction of hepatic aryl hydrocarbon hydroxylase activity in rainbow trout (Salmo gairdneri) exposed to coal liquids

1. The hepatotoxic response of rainbow trout (Salmo gairdneri) to a middle distillate (MD) and heavy distillate (HD) coal liquid was determined following administration by injection or in food. Hepatic aryl hydrocarbon hydroxylase (AHH) activity was compared to the known AHH inducer, benzo(a)pyrene. 2. Acute toxicities (LD50) of 1500 and 1410 mg/kg were obtained 120 hr after intraperitoneal injection (i.p.) for MD and HD coal liquids, respectively. Only the HD induced AHH activity when injected at 5% and 10% of the acute LD50. 3. Ingestion of 7 or 70 mg HD/kg body weight for 1 week resulted in AHH induction at 5-7 times that of control values. Levels of hepatic AHH activity in fish treated at 7 mg HD/kg declined to 2.6 times control values 7 days after exposure. Maximum induction was observed for the 70 mg HD/kg group that was provided control food for 1 week following 2 weeks of exposure. 4. The hepatic index (HI) or liver to body weight ratio generally increased along with increased activity in the enzyme response system.

Effects of inhalation exposure to a high-boiling (288 to 454 degrees C) coal liquid

Coal liquids have been evaluated in a variety of short-term toxicological assays; however, few studies have been conducted to determine the systemic effects after inhalation exposure to these materials. To extend the data base on potential health effects from coal liquefaction materials, we performed a study with solvent refined coal (SRC)-II heavy distillate (HD). Fischer-344 rats were exposed for 6 hr/day, 5 days/week for 5 or 13 weeks to an aerosol of HD (boiling range, 288 to 454 degrees C) at concentrations of 0.69, 0.14, 0.03, or 0.0 mg/liter of air for the high, middle, low, and control groups, respectively. Survival through 13 weeks of exposure was greater than 90% for all groups; body weights for exposed animals were decreased in a dose-dependent manner. Significant increases in liver weights and decreases in thymus and ovary weights were observed for treated animals compared with controls. There were also significant treatment-related decreases in erythrocytes, hemoglobin, volume of packed red blood cells, lymphocytes, eosinophils, and total white blood cells. After 5 weeks of exposure serum cholesterol concentrations increased in a dose-dependent manner for both sexes and serum triglyceride amounts decreased for males but not for females. After 13 weeks of exposure, high-dose animals had significant increases in cholesterol (males only), triglycerides, blood urea nitrogen, and serum glutamic pyruvic transaminase (SGPT; males) and significant decreases in albumin, SGPT (females), and lactate dehydrogenase (LDH). Examination of bone-marrow preparations from exposed animals demonstrated consistent decreases in the degree of cellularity, suggesting that this organ is a target for HD. Microscopic evaluation of organ sections indicated exposure-related changes for nasal mucosa, pulmonary macrophages, thymus, liver, kidney, bone marrow, ovaries, and cecum. Results from this study indicated dose-dependent increases in the severity of the lesions observed, with few effects in the low-exposure group that were attributable to the exposure.