Evaluating the Cytotoxic, Genotoxic, and Toxic Potential of Pyrolytic Tire Char Using Human Lymphocytes and a Bacterial Biosensor

Waste tires (WTs) constitute a potentially significant source of pollution, and the large quantities that are disposed of require proper handling. Pyrolysis has emerged as an environmentally friendly and effective method for WT treatment. In the present study, the cyto-genotoxic and toxic effects of untreated and acid-treated pyrolytic tire char (PTC_UN and PTC_AT, respectively) were investigated. The cytokinesis block micronucleus (CBMN) assay, using human lymphocytes, and the <i>Aliivibrio fischeri</i> bioluminescence assay were used for the assessment of cyto-genotoxicity and ecotoxicity, respectively. According to the results, both PTC_UN and PTC_AT exhibited genotoxicity at all concentrations tested (2.5, 5, and 10 μg mL^-1), which was more pronounced in the case of PTC_AT. Cytotoxicity induction was reported for PTC_UN and PTC_AT at all concentrations. Both demonstrated a relatively low potential for ecotoxicity induction against <i>A. fischeri</i>. Since the cyto-genotoxic and toxic effects of PTC_AT seemed to be more pronounced, the toxic profile of tire char should be investigated in depth before selecting the appropriate applications, thereby avoiding detrimental effects in the environment and humans alike.