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Title: Photodegradation of mutagens in solvent-refined coal liquids

Technical Report ·
DOI:https://doi.org/10.2172/5070697· OSTI ID:5070697

The purpose of this investigation was to evaluate any changes in the chemical composition and microbial mutagenicities of two representative solvent-refined coal (SRC) liquids as a function of exposure time to sunlight and air. This information was desired to assess potential health hazards arising from ground spills of these liquids during production, transport and use. Results of microbial mutagenicity assays using Salmonella typhimurium TA98, conducted after exposure, showed that the mutagenicities of both an SRC-II fuel oil blend and an SRC-I process solvent decreased continuously with exposure time to air and that the decrease was accelerated by simultaneous exposure to simulated sunlight. The liquids were exposed as thin layers supported on surfaces of glass, paper, clay or aluminum; but the type of support had little effect on the results. The contrast between these results and the reported increases of mutagenesis in organisms exposed simultaneously to coal liquids and near-ultraviolet light suggested that short-lived mutagenic intermediates, e.g., organic free radicals, were formed in the liquids during exposure to light. The highest activities of microbial mutagenicity in the SRC liquids were found in fractions rich in amino polycyclic aromatic hydrocarbons (amino PAH). After a 36-hour exposure of the fuel oil blend to air in the dark, the mutagenicity of its amine-rich fraction was reduced by 65%; whereas a 36-hour exposure in the light reduced the mutagenicity of this fraction by 92%. Similar rates of reduction in mutagenicity were achieved in exposures of the process solvent. The mutagenicities of other chemical fractions remained low during exposure.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
5070697
Report Number(s):
PNL-4982; ON: DE84010760
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English