Toxicological evaluation of exhaust emissions from light-duty vehicles using different fuel alternatives in sub-freezing conditions

Abstract

Background: Emissions from road traffic are under constant discussion since they pose a major threat to human health despite the increasingly strict emission targets and regulations. Although the new passenger car regulations have been very effective in reducing the particulate matter (PM) emissions, the aged car fleet in some EU countries remains a substantial source of PM emissions. Moreover, toxicity of PM emissions from multiple new types of biobased fuels remain uncertain and different driving conditions such as the sub-zero running temperature has been shown to affect the emissions. Overall, the current literature and experimental knowledge on the toxicology of these PM emissions and conditions is scarce. Methods: In the present study, we show that exhaust gas PM from newly regulated passenger cars fueled by different fuels at sub-zero temperatures, induce toxicological responses in vitro. We used exhaust gas volume-based PM doses to give us better insight on the real-life exposure and included one older diesel car to estimate the effect of the new emissions regulations. Results: In cars compliant with the new regulations, gasoline (E10) displayed the highest PM concentrations and toxicological responses, while the higher ethanol blend (E85) resulted in slightly lower exhaust gas PM concentrations and notably lower toxicological responses in comparison. Engines powered by modern diesel and compressed natural gas (CNG) yielded the lowest PM concentrations and toxicological responses. Conclusions: The present study shows that toxicity of the exhaust gas PM varies depending on the fuels used. Additionally, concentration and toxicity of PM from an older diesel car were vastly higher, compared to contemporary vehicles, indicating the beneficial effects of the new emissions regulations.

Air Pollution, Ultrafine Particles, and Your Brain: Are Combustion Nanoparticle Emissions and Engineered Nanoparticles Causing Preventable Fatal Neurodegenerative Diseases and Common Neuropsychiatric Outcomes?

“…Toxicological responses in vitro have been observed to be higher in older diesel car emissions compared to contemporary vehicles. 15 In general, irrespective of the fuel used, all internal combustion engines produce measurable amounts of PM and UFP emissions. This includes biofuels, renewable, or other low-carbon fuels.…”

“…Relevant to this discussion is also the toxicity of engine exhaust PM, which varies as a function of fuel type and emission control technology in use. Toxicological responses in vitro have been observed to be higher in older diesel car emissions compared to contemporary vehicles . In general, irrespective of the fuel used, all internal combustion engines produce measurable amounts of PM and UFP emissions.…”

Dynamic crosslinked polymeric nano-prodrugs for highly selective synergistic chemotherapy

“…5 G, the apoptosis rates of HepG2 were 62.3%, 58.2%, 66.7% and 67.4%, and the apoptosis rates of H22 were 56.2%, 51.2%, 57.8% and 61.9% caused by cisplatin/DMC (1:2), Pt(IV)−1, PPD-NPs (pH 7.4) and PPD-NPs (pH 6.8), respectively. This implied that cytotoxicity was mainly induced by apoptosis [35] , and the apoptosis trends were similar in the consequences of cytotoxicity.

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Effects of fuel composition and vehicle operating temperature on in vitro toxicity of exhaust emissions

“…4 In vitro toxicological research is one of the methods to further reveal the most hazardous aspects of traffic exhaust, and several in vitro submerged studies have been conducted on the toxicity of particulate matter in exhaust emissions. 12,27,28 However, toxicological experiments should increasingly represent the actual biological system to better establish the data from the most toxic emission components. 28 A possible solution for this would be advanced in vitro models, such as air-liquid interface (ALI) exposure systems, where the cells can be exposed to total exhaust emissions, including gaseous emissions such as SVOCs and nitrogen oxides (NO x ).…”