Post-Chernobyl 137Cs in the atmosphere of Thessaloniki: a consequence of the financial crisis in Greece

The background radiation level of 137Cs at the urban atmosphere of Thessaloniki has been increased during the recent decade only due to the Fukushima accident fallout. Since then, no other signal of 137Cs was observed until the winter period of 2013, when slightly elevated 137Cs concentrations were measured. The 137Cs signals observed were up to 12 μBq m−3, mainly during holidays and weekends followed by lower or even non-detectable activities in the next working days. Those episodes are attributed to the increase of biomass products combustion for residential heating as this year the tax of oil for heating was drastically raised as a consequence of the financial crisis. A preliminary survey of various wood products as well as of bottom ashes from different domestic burning devices is presented. 137Cs concentrations up to 11 Bq kg−1 were measured in wood products and up to 500 Bq kg−1 in ash samples.