Emission and transport of cesium‐137 from boreal biomass burning in the summer of 2010

Plutonium isotopes have primarily been injected to the stratosphere by the atmospheric nuclear weapon tests and the burn-up of the SNAP-9A satellite. Here we show by using published data that the stratospheric plutonium exponentially decreased with apparent residence time of 1.5 ± 0.5 years, and that the temporal variations of plutonium in surface air followed the stratospheric trends until the early 1980s. In the 2000s, plutonium and its isotope ratios in the atmosphere varied dynamically, and sporadic high concentrations of 239,240Pu reported for the lower stratospheric and upper tropospheric aerosols may be due to environmental events such as the global dust outbreaks and biomass burning.

Section: Discussionsupporting

confidence: 60%

Sources of plutonium in the atmosphere and stratosphere-troposphere mixing

Hirose

Povinec

2015

“…It has been reported that a minimum of at least 20% of labile radionuclides will be redistributed in the atmosphere after a fire, no matter whether they are deposited in the soil 3 or biomass/vegetation 37 38 39 . More specifically, the emission factors of labile radionuclides range from 20% in soil 3 up to 70–100% in vegetation for intensive wildfires 37 40 . As for the refractory radionuclides, to our knowledge, no measurements of emission factors for biomass burning exist.…”

Section: Methodsmentioning

confidence: 99%

Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Power Plant in 2015: An impact assessment

Evangeliou

Zibtsev

Myroniuk

et al. 2016

In April and August 2015, two major fires in the Chernobyl Exclusion Zone (CEZ) caused concerns about the secondary radioactive contamination that might have spread over Europe. The present paper assessed, for the first time, the impact of these fires over Europe. About 10.9 TBq of 137Cs, 1.5 TBq of 90Sr, 7.8 GBq of 238Pu, 6.3 GBq of 239Pu, 9.4 GBq of 240Pu and 29.7 GBq of 241Am were released from both fire events corresponding to a serious event. The more labile elements escaped easier from the CEZ, whereas the larger refractory particles were removed more efficiently from the atmosphere mainly affecting the CEZ and its vicinity. During the spring 2015 fires, about 93% of the labile and 97% of the refractory particles ended in Eastern European countries. Similarly, during the summer 2015 fires, about 75% of the labile and 59% of the refractory radionuclides were exported from the CEZ with the majority depositing in Belarus and Russia. Effective doses were above 1 mSv y−1 in the CEZ, but much lower in the rest of Europe contributing an additional dose to the Eastern European population, which is far below a dose from a medical X-ray.

“…Method 2 (top-down) combines EFs of 137 Cs (in gr species per kg of dry mass burned) from Hao et al 30 with combusted biomass (in kg of dry mass) from Copernicus Atmosphere Monitoring Service (CAMS) Global Fire Assimilation System (GFAS) 52 ( Figure S4a). Finally, Method 3 (top-down) uses experimental ratios of 137 Cs with particulate organic matter (POM) from Strode et al 53 for boreal regions and calculates emissions using POC from CAMS GFAS 52 ( Figure S5b).…”

Section: Radionuclide Emissionsmentioning

confidence: 99%

Uncovering transport, deposition and impact of radionuclides released after the early spring 2020 wildfires in the Chernobyl Exclusion Zone

Evangeliou

Eckhardt

2020

In the beginning of April 2020, large fires that started in the Chernobyl Exclusion Zone (CEZ) established after the Chernobyl accident in 1986 caused media and public concerns about the health impact from the resuspended radioactivity. in this paper, the emissions of previously deposited radionuclides from these fires are assessed and their dispersion and impact on the population is examined relying on the most recent data on radioactive contamination and emission factors combined with satellite observations. About 341 GBq of 137 Cs, 51 GBq of 90 Sr, 2 GBq of 238 Pu, 33 MBq of 239 Pu, 66 MBq of 240 Pu and 504 MBq of 241 Am were released in 1st-22nd April 2020 or about 1,000,000,000 times lower than the original accident in 1986 and mostly distributed in Central and East Europe. The large size of biomass burning particles carrying radionuclides prevents long-range transport as confirmed by concentrations reported in Europe. The highest cumulative effective doses (> 15 μSv) were calculated for firefighters and the population living in the CEZ, while doses were much lower in Kiev (2-5 μSv) and negligible in Belarus, Russia and Europe. All doses are radiologically insignificant and no health impact on the European population is expected from the April 2020 fires. On April 4th, 2020, the Ukrainian authorities reported that a fire started at Volodymyrivka village located in the Chernobyl Exclusion Zone (CEZ). The fire damaged up to 20 ha of forest litter, before firefighters could stop it shortly after. The same day, it was reported that another fire had started in the Kotovsky forests burning 4 ha of forest litter 1. On April 6th, 2020, actions to eliminate two more fires were reported again in Kotovsky Forest (25 ha), while on April 7th, 2020, measures were taken to extinguish a grass (6.5 ha) and a forest litter fire (4 ha) in the territory of the Kotovsky Forest in the CEZ. In the afternoon of the same day, a gust spread the grass fire across other regions of the Kotovsky forest. The fire spread to six regions of the Denysovets Forest in the CEZ 2. On April 8th, grass and litter fires continued in the Kotovsky Forest, while another fire was observed in seven regions between Poliske and Volodymyrivka villages. The same day, another grass and litter fire near the Ososhnya village was eliminated (4 ha). On April 9th, firefighting activities were still ongoing near the Chistogolovka village with a smoldering fire burning over 20 ha. Several other smoldering fires that burned shrubs were reported in the Denysovetsky forest and in Poliske and Volodymyrivka vilages 3. Firefighting activities continued the next five days in Korogodsky, Kotovsky and Denysovets regions; however, about 20 ha per day were burned. On April 14th, new fires were observed in the Parishovsky mountain, and in Janiv Lubianski approaching the city of Chernobyl. On April 15th, grass, cane and litter fires were reported in villages near the Poliske town, and in the territory of Korogodsky, Kotovsky, Denysovytsky, Paryshevsky and Lubyansky forests that ...