Half of Inhaled Soot Particles from Diesel Exhaust, Fires Gets Stuck in the Lungs
ScienceDaily (June 27, 2012) — The exhaust from diesel-fueled vehicles, wood fires and coal-driven power stations contains small particles of soot that flow out into the atmosphere. The soot is a scourge for the climate but also for human health. Now for the first time, researchers have studied in detail how diesel soot gets stuck in the lungs. The results show that more than half of all inhaled soot particles remain in the body.
The figure is higher than for most other types of particles. For example "only" 20 per cent of another type of particle from wood smoke and other biomass combustion gets stuck in the lungs. One explanation is that diesel soot is made up of smaller particles and can therefore penetrate deeper into the lungs, where it is deposited. The study was made on diesel particles (which mainly consist of soot) and was recently published in the Journal of Aerosol Science. Ten healthy people volunteered for the the study.
"Findings of this kind can be extremely useful both for researchers to determine what doses of soot we get into our lungs out of the amount we are exposed to, and to enable public authorities to establish well-founded limits for soot particles in outdoor air," says Jenny Rissler, researcher in aerosol technology at Lund University's Faculty of Engineering and responsible for publishing the study.
In population studies, other researchers have been able to observe that people who live in areas with high concentrations of particulates are more affected by both respiratory and cardiovascular diseases. But since there is no conclusive evidence that it is precisely the soot that is to blame, the authorities have so far not taken any decisions on guidelines.