I think they want you to retain more diesel soot in your lungs or maybe soot in your lungs causes global warming… Hard to tell from their opening line:
Researchers at Lund University have found that more than 50% of the inhaled diesel soot remains stuck in the lungs. It also contributes to global warming.
Aerosol particles, which are tiny airborne particles, enter the lungs when we breathe. These particles include soot, which is a by-product of combustion from wood fires, power stations using coal, and vehicles running on diesel. Soot affects both human health and the global climate. The researchers conducted a detailed study on diesel soot. When compared to diesel soot particles, only 20% of soot particles from biomass and wood smoke combustion get stuck to the lungs.
Diesel soot particles are comparatively smaller in size, which allow it to go deeper into the lungs. Jenny Rissler, a researcher at the Faculty of Engineering in Lund University, stated that the study results provide information to researchers and the public authorities on the amount of soot people are exposed to in a region and the amount of soot which is inhaled. The study comprised of 10 volunteers.
Rissler states that presently authorities have not specified the guidelines on limit of soot particles in the air. In other studies, it has been found that people living in areas containing more particulate concentration are at increased risk of cardiovascular and respiratory diseases. But these particles have not been linked to soot due to lack of evidence.
Soot particles absorb light as they are black in color. This leads to warming, which in turn can lead to a warmer climate.
The study was published in the Journal of Aerosol Science.