Combination of Pine Scent and Ozone as Super Source of Particulate Emissions From Coniferous Forests

Scientists have managed to figure out why conifer forests produce so many fine particles into the atmosphere. Aerosol particles are particularly abundant when a-pinene, the molecule responsible for the characteristic pattern of pine trees reacts with atmospheric ozone.


Atmospheric aerosol particles affect the Earth's climate by forming clouds, but at the same time they also pollute the air, thereby increasing mortality.

Aerosol particles in the atmosphere have their origins in many sources. The significant amount of aerosol particles in the atmosphere is caused by the oxidation of hydrocarbon molecules produced by trees and other plants. One of the most important hydrocarbons forming particles is a-pinene, that is, the molecule that causes the characteristic smell of pine trees

“Especially efficiently aerosols are produced when a-pinene reacts with ozone, which in turn smells “like electricity”,” explains Theo Kurtén, university lecturer in Department of Chemistry at the University of Helsinki.

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