Effect of coal mining activities and related industry on composition, cytotoxicity and genotoxicity of surrounding soils

Coal mining and related industries each leave their characteristic “metal fingerprint” in the surrounding soils. Although geochemical investigations of such soils most often indicate heavy contamination with certain metals and bioassays point to their cytotoxic and genotoxic effects, the majority of studies are based on only one of the mentioned approaches. Here, the presented study investigated the effect of coal mining activities and related industry on surrounding soils by means of both geochemical and biological tools. The multielement composition of soils and associated eluates were used for the assessment of soil contamination level and the element bioavailable fractions, respectively. For cytotoxicity and genotoxicity evaluation, shallot (Allium ascalonicum L.) roots were exposed to selected soil eluates. Root growth, frequency of mitosis, mitotic and chromosomal abnormalities in root meristem cells, level of lipid peroxidation, and DNA damage evaluated by a comet assay were scored as toxicity endpoints. The results point to significant differences in the composition of collected soils and a variety of factors that contribute not only to their total metal load but also to the observed cytotoxic and genotoxic effects; all of which emphasize the necessity of a multidisciplinary approach in assessing the impact of anthropogenic activities on the environment, especially in historical mining areas.