Burning wood in fireplaces may lead to air pollution being trapped in specific areas for longer periods and becoming more severe, especially during winter, a new study has found.
Researchers from the Climate and Atmosphere Research Center (CARE-C) of the Cyprus Institute found this to be more prevalent in urban centres, where the topography does not allow for air movement.
An example is the city of Ioannina in Greece, where the study was conducted and where air pollution during wintertime was shown to reach levels as high as those observed in large megacities that have pollution problems, such as Paris or Beijing.
The study, conducted by CyI researchers in collaboration with the National Observatory of Athens and the University of Ioannina, highlighted the occurrence of intense air pollution events during winter in Ioannina, primarily from wood burning.
The city is surrounded by mountains prohibiting atmosphere to be well mixed. During winter, a common method for home heating is wood burning particularly as the city is not connected to the national gas grid.
Wood burning is also commonly used for social and cultural occasions, for instance at Christmas and New Year celebration gatherings.
Pollutants
Wood burning is an extremely important source of numerous atmospheric pollutants such as carbon dioxides, carbon monoxide, nitrogen oxides, particulate matter and volatile organic compounds.
Researchers focused on understanding the origin, and levels of those volatile organic molecules by deploying a state-of-the-art Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-ToF-MS), capable of detecting several toxic organic molecules in the atmosphere by their precise mass, with a very high temporal resolution of one second.
The researchers also used advanced computational statistical algorithms (Positive Matrix Factorisation) to separate groups of molecules being emitted together. That information allowed the identification of the pollution sources contributing to the deterioration of air quality.
Specifically, 55% of the organic mixture was attributed to residential wood burning, while 28% was found to be emitted by fossil fuel combustion (traffic and heating). The remaining 17% was the product of daytime photochemical production.
The study highlights the important implications of heavy reliance on wood burning as a primary heat source for poorly ventilated urban centres around the world, and underscores the need for taking measures to tackle this issue as a critical step towards bettering air quality and human health.
