Acetaldehyde and formaldehyde concentrations from sites impacted by heavy-duty diesel vehicles and their correlation with the fuel composition: Diesel and diesel/biodiesel blends

The increasing of both industrialization and motorization of the world has led to a sharp rise in the demand for fossil fuels. Concern about the environmental impact caused by burning of these fuels has involved researchers that became engaged in assessing the damages of pollution not only to environment, but also to human health. In this study, carbonyl compounds (CC) were measured in vapor samples from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B5) in Salvador, Brazil. Among them, formaldehyde, acetaldehyde and propanone were the most abundant quantified compounds. Concentration levels (ppbV) for major CC detected during the sampling period ranged from 28.45 to 287.3 (formaldehyde), 24.91 to 171.3 (acetaldehyde) and 5.835 to 72.29 (propanone). The obtained data in this site was compared to formaldehyde and acetaldehyde concentrations found in other sites impacted by heavy-duty vehicles fuelled with pure diesel and diesel/biodiesel blends. All data were used to make a possible correlation with formaldehyde/acetaldehyde ratio and the relationship with the kind of fuel used by these vehicles. PCA was used to verify possible grouping among 19 sites impacted by heavy-duty vehicles and showed two major groups, one characterized by being strongly impacted and the other with a low contribution of heavy-duty vehicles. Thus, the addition of higher concentrations of biodiesel to diesel showed an improvement in the carbonyl concentration profile at places with high circulation of heavy-duty vehicles, which had similar profile to those found for sites less impacted by these kind of vehicles.