Atmospheric transformation of diesel emissions.

This paper reviews the major physical and chemical transformation the primary diesel emissions undergo during dispersion and transport in the atmosphere. Since diesel emissions contain compounds that are present in other combustion source's emissions, their atmospheric transformations are not specific to this source category only. The most important chemical reactions of diesel exhaust constituents are with OH radicals, followed by ozone, NO3 radicals and light. While data now exists concerning the chemical and physical nature and the inventory of diesel emissions, our knowledge concerning the products of their chemical transformations is still limited. In particular, there is currently very little in the literature that addresses the impact of atmospheric transformation on the health effects of inhaled diesel exhaust. As an example of such a study, the design and the preliminary data obtained from the current project executed with the aid of the European Photoreactor (EUPHORE) simulation chamber in Valencia, Spain, is discussed.