exhaust from diesel-run vehicles, wood fires and coal fired power
stations contains soot particles that not only pollute the air,
but more dangerously, stick to human lungs, says a study.
Now for the first time, Lund University researchers have shown in
a detailed study how more than half of all inhaled diesel soot
particles remain in the body.
The figure is higher than for most other types of particles. For
example, only 20 percent of another type of particle from wood
smoke and other biomass combustion gets stuck in the lungs, the
Journal of Aerosol Science reported.
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 based on diesel particles (mainly
soot), said a university statement.
"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," said Jenny Rissler, aerosol technology researcher at
Lund University's Faculty of Engineering, who led the study.
"Currently there is no specific limit for soot particles in the
air, despite the fact that soot in the air is linked to both lung
cancer and other diseases", said Rissler.
Soot particles are not affect health but may also contribute to a
warmer climate. Paradoxically, other types of aerosol particles
can partly be desirable, so far as they have a cooling effect on
the climate and thereby mitigate the warming effect of carbon
"Soot particles are black and absorbs light, thus producing a
warming effect. So it could be a double advantage to reduce it,"