ABSTRACT: Coal is a major energy source that generates diverse environmental impacts through its production, primarily by the release of coal dust particles. An aqueous coal dust extract was obtained from a mineral sample taken from one of the largest coal mines in Colombia (La Loma, Cesar), trace elements by ICP/MS were measured, and its toxicity evaluated using the zebrafish (Danio rerio) vertebrate model. In this study, zebrafish embryos were exposed to different concentrations of aqueous coal extract (0, 0.1, 1, 10, 100 and 1000 parts per million (ppm; μg/mL) to establish acute toxicity, as well as morphological and transcriptome alterations. Trace elements within the coal extract yielding the highest concentrations included Sr, Zn, Ba, As, Cu, Se, Li, Ni, Sb, Rb, Co, and Cr. In addition, Cd and Pb were found in lower concentrations. No significant difference in mortality was observed with survival near 90% in all treatments. A significant decrease in rate of hatching was observed in the 0.1 and 1000 ppm treatment groups at 72 hpf. Furthermore, no significant differences in total body length, head length, or head diameter was observed in any of the treatment groups. Transcriptomic results of zebrafish larvae revealed alterations in 77, 61, and 1,376 genes in the 1, 10, and 100 ppm treatments, respectively. Gene ontology analysis revealed gene alterations associated with hematological system development and function, tissue morphology and development, connective tissue development and function, and embryonic development. Overall, these findings are the first to identify gene expression alterations in response to a developmental aqueous coal dust residue from coal mining.
