Broda, R. (1987). Gamma spectroscopy analysis of hot particles from the Chernobyl fallout. Acta Physica Polica. B18. pg. 935-950.

• "Highly inhomogeneous distribution of Chernobyl fallout in Poland was one of the surprises contributing to serious difficulty in early estimates of the situation." (pg. 935).
• Ground level activity was observed to 360,000 Bq/m².
• Ground deposition hot spots were observed in the Masurian Lakes region as small as 30 cm in diameter with radioactivity 20 times higher than that in the larger areas surrounding them. This could have arisen as a result of erosion and washout of hot particles.
• Extensive deposition of hot particles was noted with some areas having one particle (+100 Bq) per ten square meters.
• Intense background radiation hindered the hot particle search in the Krakow area.
• One hot particle was nearly pure cerium; another had activity levels of 237,900 Bq of ¹⁰³Ru.
• "Extensive isotopic and activity ratio analysis of hot particles radionuclides in this report... gives extensive information about the age and fuel composition about the Chernobyl reactor and the processes taking place during the accident." (pg. 949).
• This is a landmark article in the literature of hot particle emissions. See the Poland listing for additional data from this article.

• ¹⁵⁴Eu and ¹⁵⁵Eu behave similarly to the nonvolatile radioisotopes ⁹⁵Zr and ⁹⁵Nb in hot particles (pg. 84), with small fractionation as compared to the large fractionation of ¹³⁷Cs and ¹⁰⁶Ru.

• The first radioactivity noted in surface air was due to sedimenting of hot particles when the main plume stayed airborne at high elevations; most hot particle deposition was in SW parts of Finland. (pg. 693).
• Scots Pine Needles were used as bioindicators for hot particle distribution; typical peak concentration activity levels: ¹⁴⁴Ce: 63 Bq per particle; ¹⁴¹Ce: 132 Bq; ¹⁰³Ru: 108 Bq; ¹⁰⁶Ru: 6.7 Bq; ⁹⁵Zr: 126 Bq; ⁹⁵Nb: 130 Bq.

• Three types of activity composition were found in airborne hot particles from Chernobyl: The most common type contained ¹⁴¹Ce, ¹⁴⁴Ce, ⁹⁵Zr and ⁹⁵Nb; the second type also included ¹⁰³Ru and ¹⁰⁶Ru; and the third type contained ¹⁰³Ru and ¹⁰⁶Ru only.

• Two types of particles noted:
1. "Mono or bielemental, since only one or two radionuclides were detected by gamma spectroscopy."
2. Particles or fragments of uranium oxide fuel containing a range of fission products found in fuel but often somewhat depleted in the non-volatile elements, such as sodium, cesium and ruthenium."
• Particle size ranges: 0.5 to 30 µm (Minsk).

• Particles with high specific activity were investigated in Poland, Greece and Germany; many had a high proportion of ¹⁰³Ru and ¹⁰⁶Ru.
• Hot particles were noted from NE Poland with activity levels up to 139,000 Bq of ^103,106Ru. ¹⁰⁶Ru ratios were from 4.42 to 8.06.

• Hot particles contribution to the total activity in the 30 km zone was found to be not less than 65%.
• Linear size range: 0.5 to 100 µm.

• Core fragment hot spots measured in trousers and shoes by Dutch researchers of travelers returning from Kiev and Minsk... Gamma activity in hot spots to 850 Bq with smaller peaks of alpha emitting ⁴²Cm, ^239,240Pu, ^243,244Cm, ²³⁸Pu and possibly ²⁴¹Am.