Long-range transported biomass-burning aerosols from large-scale wildfires in Russia and surrounding regions with respect to radioactive tracers

Biomass burning caused by anthropogenic activity such as agriculture-burning periods (common practice during harvesting, post-harvesting, or preplanting) or naturally occurring forest fires, and domestic biofuel combustion is a frequent phenomenon causing global concern. Agricultural burning, although restricted in some countries, significantly contributes to regional air-quality deterioration and national emissions. This work focuses on atmospheric measurements at the suburbs of Athens, on August 2010, during extensive forest fires in the European Russian central plains. The effect of these fires on the measured concentrations of specific radioactive isotopes and biomass-burning tracers was studied, for long-range transport of aerosols from Russian plains. Mean total beta radioactivity was found more than 2.5 times higher during the incident compared to background values. High values were also reported for the isotope ⁴⁰K, and its fluctuations were following the course of the event. ⁷Be showed no significant difference between the two periods, which is expected due to its origin. During the event ²³⁴Th (²³⁸U), activity concentrations were also detected. Their fluctuations showed no significant correlation with the course of the event. The average values during the period before and right after the incident is for organic carbon 2.74 μg/m³, elemental carbon 1.53 μg/m³, and for carbonate carbon 0.16 μg/m³. During the incident, the highest values were observed on August 18, with concentrations for organic carbon 5.49 μg/m³, elemental carbon 0.64 μg/m³, and carbonate carbon 0.32 μg/m³. This fact may be considered as an indicator of biomass-burning incident during the period 12–19 August 2010.