Cytometric and microscopic analysis of cell death induced by diesel engine emissions using BAT-CELL method exposure

Abstract

Despite the growing popularity of electromobility and the restrictive emission standards, gases emitted from combustion engines still pose a serious threat to public health and the environment. Current regulations, such as the Euro standards, focus on limiting quantitative emissions of exhaust gas mixtures but do not reflect their actual toxicity. The aim of this study was to evaluate the cytotoxicity of diesel exhaust gases emitted by two vehicles meeting Euro 3 and Euro 6 standards using L929 mouse fibroblast cells. The evaluation used the BAT-CELL method, flow cytometry and scanning electron microscopy (SEM). Cells were directly exposed to exhaust gases emitted during various engine operating conditions. Then, the cell viability, apoptosis, cell cycle and external morphological changes were assessed. Cytometry results showed that exhaust gases emitted at idle had the greatest negative impact on cells that underwent apoptosis. Emissions recorded at higher driving speeds showed less toxicity, and in the case of the Euro 6 vehicle, it was observed that the emissions promoted cell proliferation. Scanning electron microscopy confirmed morphological changes that may indicate cell necrosis. Research suggests that modern emission standards, despite limiting the quantity of pollutants, do not guarantee reduction of toxicity at the cellular level, which emphasizes the need for further research on the actual impact of exhaust gases on human health.