Public health impact of diesel exhaust: toxicity of nano-sized diesel exhaust particles - Part 1

Abstract

Diesel exhaust particles (DEP) can exist in a range of particle sizes, such as PM10, PM2.5, and nanoparticles. It is also suspected that nano- or ultra fine particles make up a large part of particulate components in DEP. These particles can also make up a large component of ambient air pollution. Epidemiological and human studies have demonstrated an association between air pollution and various adverse health outcomes, including morbidity such as asthma, and mortality such as cancer, although the underlying biological mechanism is not well understood. There is currently no occupational exposure level for diesel fumes in the United Kingdom, however, Western Australia has a provisional standard and BHP and some other mines have adopted the recommended standard of 0.2 mg/m3 for sub micron DPM or 0.1 mg/m3 for elemental carbon. It is known that breathing high concentrations of diesel exhaust induces pulmonary inflammation, broncho-constriction, and oxidative stress. Current research practice mainly focuses on two particle sizes namely: coarse (2.5-10ì) and fine (< 2.5ì). It is suggested that more research should be undertaken on smaller nanoparticles (<100 nm) because it is hypothesised that they could cause more harm.