Journal of Environmental Radioactivity 64 (2003) 175–193 www.elsevier.com/locate/jenvrad Uranium ores and depleted uranium in the environment, with a reference to uranium in the biosphere from the Erzgebirge/Sachsen, Germany A. Meinrath a,∗, P. Schneider b, G. Meinrath c,d a Klinikum, Bischof-Piligrim Str. 1, 94032 Passau, FRG, Germany b Hydroisotop-Piewak GmbH Oberfrohnaer Str. 84 09117 Chemnitz, FRG, Germany c RER Consultants, Schießstattweg 3a, 94032 Passau, FRG, Germany d Technical University Mining Academy Freiberg, Institute of Geology, G.-Zeuner-Str. 12, 09596 Freiberg, FRG, Germany Received 26 June 2001; received in revised form 18 October 2001; accepted 22 October 2001 Abstract The Erzgebirge (‘Ore Mountains’) area in the eastern part of Germany was a major source of uranium for Soviet nuclear programs between 1945 and 1989. During this time, the former German Democratic Republic became the third largest uranium producer in the world. The high abundance of uranium in the geological formations of the Erzgebirge are mirrored in the discovery of uranium by M. Klaproth close to Freiberg City in 1789 and the description of the so-called ‘Schneeberg’ disease, lung cancer caused in miners by the accumulation of the uranium decay product, radon, in the subsurfaces of shafts. Since 1991, remediation and miti- gation of uranium at production facilities, rock piles and mill tailings has taken place. In parallel, efforts were initiated to assess the likely adverse effects of uranium mining to humans. The costs of these activities amount to about 6.5 109 Euro. A comparison with concentrations of depleted uranium at certain sites is given. 2002 Elsevier Science Ltd. All rights reserved. Keywords: Uranium; Depleted uranium; Uranium mining area remediation; Natural abundance; Health effects ∗ Corresponding author: Tel./fax: +49 851 70372. E-mail address: [email protected] (A. Meinrath). 0265-931X/02/$ - see front matter 2002 Elsevier Science Ltd. All rights reserved. PII: S 02 65 -931X(02)00048-6 176 A. Meinrath et al. / J. Environ. Radioactivity 64 (2003) 175–193 1. Introduction A connection was made in recent years between the release of depleted uranium (DU) during the war activities of the Gulf War and the Kosovo air strikes and certain adverse health effects observed in soldiers serving during these wars. During the bombardment of armoured installations, depleted uranium used in armour-breaking bullets was released upon impact or by corrosion of the bullet mantel materials. Uranium, however, is an almost ubiquitously occurring element. Therefore, adverse health effects were also assessed in the Saxonian mining area, a densely populated part of Eastern Germany, where uranium has been exploited on a large scale with little attention to possible long-term environmental and health effects (Gatzweiler and Mager, 1993). After 1945, the Soviet government exchanged a sector of Berlin for Saxony, which had been under American control after the German surrender in World War II. The mining and treatment of uranium ores took place under the auspices of the Soviet Enterprise (SAG), which later became the Soviet-German Enterprise (SDAG) WIS- MUT. After uranium production activities were stopped, the open pit mines, subsur- face mines, uranium extraction and leaching installations, as well as the enormous heaps of partially leached mill tailings, posed and still pose an eminent ecological and financial risk and a challenge to remediators and licensing authorities (Knoch- Weber, 1998; Meinrath et al., 2000). The former German Democratic Republic (GDR) was the third largest producer of uranium until 1991 when uranium production was halted after the German reuni- fication in 1989. Uranium exploited in the GDR (and Czechoslovakia) served the former Soviet Union’s strategic needs for uranium from 1945 until 1989. Conse- quently, protection of the workers and the environment was of secondary importance. The total amount of mined material (ores and tailings) was 1200 million tons. 200 million tons were transported to processing plants. The remaining 1000 million tons were dumped in nature, partly forming new landscapes. Dumping occurred without protection for ground and surface water, leaching by rain or distribution of uranium- bearing dust by wind. A total of 231,000 tons of uranium were produced and trans- ported to the Soviet Union, from which 126,000 tons had been mined in Saxony. Currently, some of the sites affected by uranium mining activities have been under the jurisdiction of the federal government since 1961 and in the process of reme- diation and mitigation (Gatzweiler and Mager, 1993; Flesch et al., 1998). Those sites transferred to the local authorities before 1961, remain under the jurisdiction of the local communities and their future is uncertain. Of the 27 sites that have been exploited in total, 23 sites have been exhausted and four sites still contain some thousands of tons of uranium. The concentration of uranium in the ores was 0.04%–0.11%. The sandstone mines at Ko¨nigstein contain about 0.08%. The characterization of the WISMUT mining areas in Saxony is sum- marized in Table 1. Central processing of saxonian (and thuringian) uranium ores was performed in Crossen. Saxony comprises an area of 18.338 km2 with currently about 4.7 million inhabi- tants. The population decreased after 1989 by about 1 million, due to demographic A. Meinrath et al. / J. Environ. Radioactivity 64 (2003) 175 Table 1 Characterization of Wismut mining areas in Saxony (Wolkersdorfer, 1996) Location Characterization Uranium deposits Amount UO2 mined Schlema Hydrothemal vein deposit Niederschlema/Alberoda 81 kta Tellerha¨user, Oberschlema, “Weißer Hirsch”, Johanngeorgenstadt, 21 kt Antonstal, Seiffenbach, Zobes, Ba¨renstein, Schneckenstein, Marienberg, Schneeberg, Po¨hla, Geyer Ko¨nigstein Cretacious sandstone Ko¨nigstein, Pirna, Thu¨rmsdorf, Rosenthal 19 kt Freital Permian hard coal Heidenschanze, Bannewitz-Gittersee 4 kt a kt: 1000 tons. – 193 177 178 A. Meinrath et al. / J. Environ. Radioactivity 64 (2003) 175–193 and migration effects. Due to the mining activities, the major mining areas of Aue, Schwarzenberg and Schneeberg are especially densely populated with about 300 inhabitants per km2. Fig. 1 gives a map of the German federal state of Saxony, together with the evalu- ated uranium contents from an aerogamma survey using the 238U progeny 214Bi (Saxonian Federal Agency of Environment and Geology, 1993). The local variation of uranium in the rock formations is clearly seen. The dark spots characterize mill tailings and production sites notably at Crossen (processing/sedimentation pond), Schneeberg and Aue (mill tailings), Dresden/Gittersee and Ko¨nigstein. Note that the sites of Dresden/Gittersee (Junghans and Helling, 1998) and Johanngeorgenstadt are close to densely populated areas. In 1953, a peak number of 115,405 workers in the Saxonian uranium industry were reported; the majority of whom worked in direct contact with uranium ores and processed uranium. The total number of workers will probably never be retraced precisely, but the estimated number ranges from 400,000 to 600,000 persons with Fig. 1. Aerogamma survey of uranium contents in rocks and soil of the German federal state Sachsen (Saxony). The uranium is associated mostly with variszic granite rocks in the Erzgebirge region forming the political border with the Czech Republic to the south. To the east, Poland is located. The highest uranium concentrations shown by the dark areas are due to uranium mining and processing sites. The sites of Crossen, Johanngeorgenstadt, Schneeberg/Aue, Dresden/Gittersee and Ko¨nigstein (subsurface sandstone deposit and surface uranium mill tailing) are shown together with the cities of Freiberg, Chem- nitz and Dresden (Saxonian Federal Agency of Environment and Geology, 1993). A. Meinrath et al. / J. Environ. Radioactivity 64 (2003) 175–193 179 about 50% working in the mines or processing plants (Schro¨der et al., 1997). From 1963 to 1989, a constant average of 45,000 persons were employed with the majority working with uranium. This communication collates data and facts from a century-long experience with increased uranium content in the geosphere. This experience will be compared to the scenarios developed concerning the use of depleted uranium (DU) during Gulf War (GW) and Kosovo Air Strikes, as well as to the application of DU in tank armour and in civilian airplanes (McDiarmid, 2001). 2. Natural uranium and depleted uranium Uranium was discovered in 1789 by Martin Klaproth in an ore near Freiberg, Germany. This is in a mountainous region that comprizes a varizic geologic forma- tion at the border between Germany’s federal state, Sachsen (Saxony), and the Czech Republic to the south. This area is called ‘Erzgebirge’ (literally translated ‘Ore Mountains’) and is rich in minerals. Notably, in the 15th–17th century it was a center of silver mining. The city of Jachimov (Czech Republic) was known as Joachimsthal in the late 19th century and its name continues in the name ‘dollar’ (‘Thaler’) (Zeman and Benes, 1995). Other minerals, including nickel, cobalt, and germanium, were discovered during the analysis of the ore by the chemist Clemens Winkler in 1846 at the Freiberg School of Mines, the world’s first mining academy. The intense min- ing activities around Freiberg took place in a granite formation with an abundance of uranium. Its radon progeny had taken its toll on the miners causing the so-called ‘Schneeberg disease’ (lung cancer) (Kreuzer et al., 2000). Uranium (Z=92) is the heaviest element occurring naturally in weighable amounts. Despite its high atomic number, it is by no means a rare element. Its relative abun- dance compares to silver, gold and the light rare earths elements and it is more common than tin, mercury and lead. Its naturally occurring isotopes have masses 238, 235 and 234. All isotopes are radioactive (cf. Table 2) (Lieser, 1980). The average Uranium concentrations in the earth’s crust are about 3 mg kgϪ1. Calcu- lations comparing the heat flow in oceans and continents show that the decay of uranium accounts for the majority of the continental heat production (Rogers and Adams, 1969).