Genotoxicity of Diesel Particulate Matter Emitted by Port-Injection of Hydrous Ethanol and n-Butanol

Abstract

This work evaluated the genotoxic potential of the soluble organic material (SOM) extracted from the particulate matter (PM) emitted by an automotive diesel engine. The engine was modified to operate with a home-made multipoint-port injection system to substitute 10% of ultralow-sulfur diesel (ULSD) fuel in energy basis by hydrous ethanol (h-Et) or n-butanol (n-Bu) injected into the manifold during the intake stroke. A low engine load mode named M4 (43 N·m at 2410 min−1) and a medium-load mode M2 (95 N·m at 2410 min−1) were selected from the vehicle homologation cycle. PM was collected with a stainless steel filter located 1.5 m downstream the exhaust manifold. The SOM of the PM was extracted to evaluate the genotoxic activity on human lymphocytes using the comet assay. Results indicated that independently of the mode, the SOM coming from alcohols led more genotoxicity than ULSD, following the order h-Et > n-Bu > ULSD. The low engine load operation exhibited much more deoxyribonucleic acid (DNA) damage than mode M2, especially the PM produced by hydrous ethanol port-injection. Although further research is still necessary, these findings suggest that the biology activity of the SOM coming from alcohols PM could be a barrier for the implementation of alcohol port-injection technology.

Alteration in the gene expression of the HepG2 cell line by exposure to particulate matter (PM) of diesel

“…Concerning the influence of the engine load, the organic extract obtained at 43 Nm of torque was more mutagenic, which results in agreement with other investigations [12,[20][21][22]79]. This can be explained because the engines that remain on idle or low load for long periods, operate with an excess of air and therefore, the combustion efficiency is reduced, and the emission of particles is favored [15,26].…”

“…In an earlier research, dualinjected ethanol/diesel was genotoxic and induced a greater number of cells with damage on human lymphocytes compared to fossil diesel. These effects were influenced by the operating conditions of the engine, the extracts from a low load (43Nm of torque) displayed higher genotoxicity [22]. The differences detected in the genotoxic profiles of the PM the evaluated fuels could be because replacing 10% of the energy fraction of diesel with ethanol through port injection produce more organic carbon emissions, total hydrocarbons [26], and high content of oxygenated and aliphatic groups compared to fossil diesel [50].…”

“…The PM emitted by diesel engines is heterogeneous and varies in composition, physicochemical properties, and toxicity. These features depend on the technology and operating conditions of the engine, as well as the type of fuel used [12,[20][21][22].…”

“…Although biodiesel and bioethanol, both derived from vegetable biomass, have been employed in blends with fossil diesel [23][24][25][26][27], information on the impact of their PM emissions is insufficient and contradictory. Hence, there is a growing concern about its potential effects on health [11,22,[28][29][30].…”

Interactions between aftertreatment systems architecture and combustion of oxygenated fuels for improved low temperature catalysts activity

“…Furthermore, butanol has higher heating value, higher cetane number [10] and it is less volatile [11], less hydrophilic and also less polar than other lighter alcohols. However, more studies are needed to assess its energy intesity and green gas house emissions in life cycle analysis, its availablity to replace a realistic share of diesel fuel in the current market and the enhaced biological activity of its exhaust gas as reported in [12].…”