Europe-Wide Atmospheric Radionuclide Dispersion by Unprecedented Wildfires in the Chernobyl Exclusion Zone, April 2020

Abstract

From early April 2020, wildfires raged in the highly contaminated areas around the Chernobyl nuclear power plant (CNPP), Ukraine. For about 4 weeks, the fires spread around and into the Chernobyl exclusion zone (CEZ) and came within a few kilometers of both the CNPP and radioactive waste storage facilities. Wildfires occurred on several occasions throughout the month of April. They were extinguished, but weather conditions and the spread of fires by airborne embers and smoldering fires led to new fires starting at different locations of the CEZ. The forest fires were only completely under control at the beginning of May, thanks to the tireless and incessant work of the firefighters and a period of sustained precipitation. In total, 0.7−1.2 TBq 137 Cs were released into the atmosphere. Smoke plumes partly spread south and west and contributed to the detection of airborne 137 Cs over the Ukrainian territory and as far away as Western Europe. The increase in airborne 137 Cs ranged from several hundred μBq•m −3 in northern Ukraine to trace levels of a few μBq•m −3 or even within the usual background level in other European countries. Dispersion modeling determined the plume arrival time and was helpful in the assessment of the possible increase in airborne 137 Cs concentrations in Europe. Detections of airborne 90 Sr (emission estimate 345−612 GBq) and Pu (up to 75 GBq, mostly 241 Pu) were reported from the CEZ. Americium-241 represented only 1.4% of the total source term corresponding to the studied anthropogenic radionuclides but would have contributed up to 80% of the inhalation dose.

Disproportionately High Contributions of 60 Year Old Weapons-137Cs Explain the Persistence of Radioactive Contamination in Bavarian Wild Boars

“…For weapons- 137 Cs, the cessation of atmospheric tests resulted in no noteworthy new weapons- 137 Cs fallout after the last test in 1980. Nowadays, the baseline of airborne 137 Cs (<10 μBq·m –3 in Germany) contributes insignificantly to the relatively high inventory in soil , and consequently in wild boars. Considering that the above-mentioned contamination level is orders of magnitude greater than the 137 Cs inventories reported in less contaminated regions, , it suggests a substantial impact of Chornobyl- 137 Cs on the Bavarian ecosystem.…”

Wildfires and the COVID-19 pandemic: a systematized literature review of converging health crises

“…This affects the extent to which findings are generalizable. Wildfires also occurred elsewhere during this period including Siberia [2], Ukraine [55], the Brazilian Pantanal [56], China [57,58], Indonesia [59], India [60], Colombia [61], and across the Mediterranean [62]. Further research is warranted into how these wildfires converged with the COVID-19 pandemic in these localities (i.e.…”

“…Direct exposure to harmful wildfire smoke is much more far-ranging than indicated by the studies identified in this review. For example, radioactive smoke from the 2020 wildfires in the Chernobyl Exclusion Zone in Ukraine was detected in Western Europe [55]. Harmful smoke from the 2021 Bootleg fire in the western United States traveled across the continent [63,64].…”

Investigations on the source term of the detection of radionuclides in North of Europe in June 2020

“…The approach consists in the minimization of a cost function which measures the mismatch between modelled and observed 134 Cs air concentration. Regularization techniques are applied to ensure the existence and the unicity of the solution [3]. Then, for each optimal inverted source related to each grid point, the agreement between modelled and observed air concentration measurements is assessed using the factor 5 indicator (FAC5).…”