Toxicologic studies of emissions from coal gasification process. I. Subchronic feeding studies

The increasing use of new sources of energy may result in additional contamination of the human environment with inorganic and organic pollutants which are not yet adequately investigated with regard to their potential impact on human health. However, some evidence exists that several trace inorganic and organic contaminants found in coal processing residues may constitute potential health problems. Therefore, the comparative biological hazards of solid wastes and effluents from a Lurgi coal gasification plant were initially evaluated using acute and chronic feeding experiments in male and female rats. In the subchronic experiment, six-week old animals were fed diets wih various levels of ash (slag) additive (0.5%, 1%, and 5%) for period of 16 weeks. Following exposure, blood samples were taken and 22-hour urine samples were collected. Livers and kidneys, and testicles in males, were taken for trace element analysis or histologic examination. The urinary values, erythrocyte and leucocyte count, hemoglobin, packed cell volume, and concentration of trace elements in exposed animals were determined. The addition of ash (slag) to the diet in concentrations much higher than expected in conditions of environmental contamination had no measurable health effects. Although these initial results obtained in relatively short-term experiments cannot be directly extrapolated to human health effects, particularly not for carcinogenic assessment, there is an indication that exposure to solid wastes from the coal gasification plant may not be toxic.