Contrary to previous studies, diesel exhausts contribute more secondary organic aerosols than those from gasoline, as claimed by a recent study conducted by University of California – Berkeley.
It is important to determine the main sources of secondary organic aerosols for they are known to be detrimental to human health; and according to the latest study, it is not the gasoline that is majorly responsible for these air pollutants, but rather, the diesel.
While both diesel and gasoline are important sources of air pollution, an estimated 65 to 90% of an area’s secondary organic aerosols emissions from vehicles are caused by diesel, depending on the relative amounts of fuels used in the area.
There have been a few studies (Atmos.Chem.Phys., Geophys.Research.Letters, Geophys.Research.Letters2, Trans.Amer.Geophys.Union) on this issue between gasoline and diesel, but UC Berkeley researchers claim that their data gathered, chemical compositions from actual vehicle emissions, are the most comprehensive so far.
The study’s lead author, Drew Gentner, a Ph.D. graduate in civil and environmental engineering from UC Berkeley, says, “The data from our study contains the most comprehensive chemical detail to date on diesel and gasoline emissions.
This presents many opportunities to assess the chemistry of these compounds in the atmosphere and the impacts of these sources. We expect that these findings will help policymakers improve air pollution control measures in the state, and also other parts of the world.”
[n.r.: Now, for the second part of the equation, if you look at European small diesel cars, they’re cleaner than most of their gasoline counterparts on the road. That’s because diesel technology has evolved in the meanwhile, and because diesel cars eat up much less fuel than gasoline cars, it is often discarded as an option on the U.S. auto market. Why that happens – it’s easy to guess. Of course a 20-year-old truck will be dirtier in these circumstances.]