Analysis of cytotoxicity and genotoxicity of diesel exhaust PM2.5 generated from diesel and dual natural gas-diesel engines

Diesel exhaust particles (DEPs) are atmospheric pollutants associated with adverse health effects. In response to their impact, natural gas (NG) has emerged as a promising alternative fuel due to its cleaner combustion. Although the cytotoxicity and genotoxicity of DEPs from diesel or NG engines have been extensively studied, the impact of dual natural gas-diesel systems remains unexplored. This study evaluated the toxicity of DEPs (PM2.5) emitted by an engine in diesel mode and dual natural gas-diesel mode on cellular parameters such as viability, apoptosis, oxidative stress, and DNA damage. The results showed that diesel DEPs reduced cell viability by up to 31 %, compared to a 19.2 % reduction with dual-mode DEPs. Apoptosis induction was also higher with diesel DEPs, with a 7 % increase compared to the dual mode. While dual-mode DEPs increased the production of reactive oxygen species (ROS) without causing DNA damage, diesel DEPs generated high ROS levels and measurable DNA damage. These differences could be attributed to the physicochemical characteristics of each mode, as diesel DEPs contained higher concentrations of polycyclic aromatic hydrocarbons (PAHs). This study addresses a research gap by quantifying the health effects of emissions from dual-fuel engines and highlights the potential of these systems to reduce DEP-induced toxicity.