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

## TL;DR

This study evaluates the toxic effects of tire char from waste tire pyrolysis on human cells and bacteria, finding significant genotoxic and cytotoxic effects.

## Contribution

The study compares the toxic effects of untreated and acid-treated pyrolytic tire char using human lymphocytes and a bacterial biosensor.

## Key findings

- Both untreated and acid-treated tire char showed genotoxicity in human lymphocytes at all tested concentrations.
- Cytotoxicity was observed for both types of tire char at all concentrations.
- The acid-treated tire char exhibited more pronounced toxic effects compared to the untreated char.

## Abstract

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 (PTCUN and PTCAT, respectively) were investigated. The cytokinesis block micronucleus (CBMN) assay, using human lymphocytes, and the Aliivibrio fischeri bioluminescence assay were used for the assessment of cyto-genotoxicity and ecotoxicity, respectively. According to the results, both PTCUN and PTCAT exhibited genotoxicity at all concentrations tested (2.5, 5, and 10 μg mL−1), which was more pronounced in the case of PTCAT. Cytotoxicity induction was reported for PTCUN and PTCAT at all concentrations. Both demonstrated a relatively low potential for ecotoxicity induction against A. fischeri. Since the cyto-genotoxic and toxic effects of PTCAT 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.