Disposal of chemical weapons in the Baltic Sea

the Science of the Total Environment An ~ Jo~rmd for S d m t t O c R ~ b Irate the E n ~ M m d ~s R e ~ l d p wUh M ~

ELSEVIER

The Scienceof the Total Environment206 (1997)267-273

Disposal of chemical weapons in the Baltic Sea G.P. Glasby* Department of Earth Sciences, Universityof Sheffield, Sheffield S3 7HF, UK

Received3 June 1997;accepted 9 August 1997

Abstract Large quantities of chemical warfare agents were dumped in the Baltic Sea after World War II (WWII). This included 32000 t of chemical munitions containing approximately 11000 t of chemical warfare agents which were dumped into the Bornholm Basin and 2000 t of chemical munitions containing approximately 1000 t in the Gotland Basin. Because this material was contained in wooden crates, it was distributed throughout the Baltic. The long-term environmental impact of these agents is unknown. © 1997 Elsevier Science B.V. Keywords: Chemical weapons; Toxic agents; Baltic Sea

1. Introduction When the Allies occupied Germany at the end of World War II (WWII), they found large stockpiles of chemical weapons. The question of what to do with these very toxic materials posed a serious dilemma. Ultimately, large quantities of them were dumped in the Baltic Sea which is, of course, a totally unsuitable environment for disposing of such material. However, the responsibility for such disposal lay with the military authorities in the period of post-war austerity when environmental concerns had a low priority. The problem with producing hazardous material, such as chemical weapons for military purposes is that

* Corresponding author.

ultimately it must be disposed of. One of the aims of this article is to demonstrate some of the hidden environmental problems of military activity which are not often brought into public view. It may seem odd that this topic has not received more attention over the past 50 years in view of its obvious importance. The principal reason for this was the cold war which effectively precluded collaboration between the Soviet Union and the N A T O countries. Furthermore, any detailed investigation was seen as being expensive and possibly dangerous and the safest option was thought to be to leave the chemical weapons where they were on the seafloor. It is therefore only over the last few years that the issue has come of interest again and the potential environmental implications better appreciated. Nonetheless, this has resulted in very little in the way of

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G.P. Glasby / The Science of the Total Environment 206 (1997) 267-273

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field work, perhaps because of the difficulty of any practical solution to the problem. Only recently has a major volume on this topic been published (Kaffka, 1996). 2. Production

During WWlI, both sides produced chemical warfare agents. Germany produced approximately 65000 tonnes, of which 39% was mustard gas (Table 1). Britain produced almost 55 000 t consisting of 40 000 t of mustard gas and 14 000 t of phosgene and tear gas (Pearson, 1995). The Soviet Union also produced a large, unspecified amount of these agents. In 1942, Hitler intended to deploy 'Geheimwaffe' (in this case meaning chemical weapons) on the eastern front but this was already known in Moscow early that year (Anon, 1994). Specific warnings of retaliation by Churchill in 1942 and Stalin and Roosevelt in 1943 prevented their use (Anon, 1994; Pearson, 1995). At the end of the war therefore, a large arsenal of some 296 000 t of chemical weapons was discovered in Germany by the Allies (Table 2). This consisted of various types of munitions including aerial bombs, artillery shells, high-explosive bombs, mines, encasements, smoke grenades, containers and drums. Of these, aerial bombs were the most significant (over 70% by weight). The amount of active agent in the weapons depended on the use of the weapon and the thickness of its casing. A bomb might contain approximately 60% of active agent and an artillery shell approximately 10%. Some of the weapons found Table 1 Chemical warfare agents produced in Germany between 1939 and 1945 (HELCOM, 1994) Warfare agent

Quantity (t)

Effects

Mustard gas Clark I Clark II Adamsite Arsenic oil Chloracetophenone Phosgene Nitrogen mustard Tabun

25 000 1500 100 3900 7500 7100 5900 2 000 12 000

Blister gas Nose and throat irritants Nose and throat irritants Nose and throat irritants ? Tear gases Lung irritants Blister gas Nerve gas

Table 2 Chemical munitions and warfare agents found in Germany between the end of World War II and 1948 (HELCOM, 1994) Occupation zone

Quantity (t)

American British French Soviet

93 995 122 508 9100 70 500

Total

296103

contained no active agent. However, information on the amounts and types of the various weapons is not well known. These weapons were either destroyed (incinerated), buried in flooded mines, dumped at sea or transported abroad for study or stockpiling (Anon, 1993a; Pearson, 1995). Of these options, it was decided that the bulk of the munitions should be disposed of by dumping at sea (Pearson, 1995). The original idea was that these weapons should be dumped in the Atlantic Ocean at a depth of 4000 m, 200 nm NE of the Faroes. However, the Soviet merchant and naval fleets had no special ships for this purpose and therefore dumped the material in the Baltic Sea (Anon, 1994). 3. Disposal at sea

From 1945 to 1948, the British and American occupation forces sank one German merchant vessel in the Norwegian Sea and 41-43 such vessels at two sites in the Skagerrak (Anon, 1993a,b; HELCOM, 1994, 1996). These vessels contained approximately 150000 t of chemical weapons and conventional ammunition. The French occupation forces also sank two vessels containing 1500 t at another site in the Skagerrak. Most of this material was dumped at depths of approximately 600 m, although some was dumped at shallower depths (200 m). These weapons were therefore contained within sunken vessels at moderate depths. In addition, substantial amounts of chemical weapons were dumped within the Baltic Sea. Shortly before the end of the war, the Germans sank two vessels loaded with nerve agent (tabun)

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projectiles at a depth of 30 m in muddy sediments in the Little Belt off Denmark. Between 1959 and 1960, the tabun shells were recovered from these vessels, set in concrete and dumped west of the Bay of Biscay. Between 1947 and 1948, the Soviet Military Administration in Germany dumped 32000 t of chemical munitions containing approximately 11000 t of chemical warfare agents in the Bornholm Basin at depths of 70-105 m and a further 2000 t of chemical munitions containing approximately 1000 t of chemical warfare agents in the Gotland Basin at depths of 70-120 m. The material deposited in the Bornholm Basin consisted of approximately 410 000 projectiles, 71500 x 250-kg aerial bombs, 1000 x 1.5-t drums all containing mustard gas, 10400 mines and 7900 containers filled with cyclone B and 17000 bombs containing adamsite (Anon, 1993a, Theobald, 1994). Both the basins into which these weapons were dumped are characterized by stable stratification with anoxic conditions developing below the halocline and only slight bottom currents except during exceptional periods of flushing of the basins. This material had been stored at Wolgast on the Peene Delta in the former German Democratic Republic and was transported by eight former German ships. Subsequently, 200-300 t of the abandoned chemical weapons were discovered in the German Democratic Republic after 1952 and deposited in the Bornholm Basin. In fact, this material was not dumped within the planned 3 nautical mile radii because it was contained in wooden crates which floated and drifted as far as the Swedish coast. Navigation was by dead reckoning and was in error on days with poor visibility. Most importantly, dumping was carried out whilst the ships were underway to the target areas. As a result, the material was widely scattered throughout the Baltic. Unconfirmed reports also suggest that the British Military Authority ordered the sinking of four ships containing approximately 15 000 t of chemical munitions SW of Bornholm in 1946 (Anon, 1993a). In summary, approximately 40000 tonnes of chemical munitions containing not more than 13 000 t of chemical warfare agents are known to

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have been dumped in the Baltic Sea in the period after WWlI. The method of dumping in the Baltic contrasts with that employed in the Skaggerak and Little Belt where whole ships containing the munitions were sunk which prevented their further spreading from the dump site. Of course, with hindsight, the Baltic Sea is not an ideal place to dump toxic chemicals. The Baltic is a relatively shallow-water (average depth of the central Baltic 65 m), semi-enclosed basin with a restricted exchange with the North Sea (Glasby et al., 1997). Less than 5% of Baltic seawater escapes to the North Sea each year. In addition, the Baltic Sea is a very dynamic environment. Of particular importance are the major storms which occur about once in a decade or so and introduce in excess of 100 km 3 of North Sea water into the Baltic within several days. During such events, the anoxic basins of the Baltic (including the Gotland and Bornholm Basins), which comprise 5% of the total area of the Baltic, are flushed and the sediment of the surrounding areas are extensively reworked. In fact, 89% of the terrigenous sediment in the Baltic is derived from erosion of the adjacent seashore and of seafloor sediments and only 11% introduced directly from rivers. This emphasizes the dynamic nature of the Baltic Sea. The sediments of the Gotland and Bornholm Basins consist of thick muds into which the canisters would have been expected to have sunk. Under the anoxic conditions encountered there, the steel casings may have been reduced to iron sulphides. However, elevated areas adjacent to the basins consist of sands and tills with sometimes zero rates of sedimentation. This means that any canister deposited there could have remained exposed at the sediment surface under the influence of periodic, strong bottom currents. Under the oxic conditions encountered there, the steel casings may have been oxidized to iron oxyhydroxides (rust). It is believed that corrosion processes would have been much slower in anoxic compared to oxic environments. According to Anon (1993a), stratification of waters in the anoxic basins should have prevented any exchange of materials across the halocline such that near-bottom waters would have been seldom renewed. However, as seen earlier, periodic, major flushing means that any

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Table 3 Quantities of chemical munitions and warfare agents dumped in the Baltic Sea (Anon, 1993a) Area

Quantities of munitions (t)

Estimated quantities of warfare agents (t)

Types of warfare agents

Bornholm Basin

35 300 (certain) to 43 300 (uncertain)

5300-6500

Mustard gas Viscous mustard gas Clark I Clark II Adamsite Chloroacetophenone Less certain Phosgene Nitrogen mustard Tabun

Area SW of Bornholm

Up to 15 000 (uncertain)

2250

Not known

Gotland Basin

2000

300

Not known

Little Belt

5000

750

Tabun Phosgene

toxic material stored within these bottom waters of these basins would have been dispersed throughout the Baltic every decade or so.

4. Types of chemical warfare agents dumped The quantities and types of chemical warfare agents dumped in the Baltic Sea are listed in Table 3. Their toxicity depends on their long-term stability and their hydrolysis characteristics in seawater. Mustard gas is 2,2'-dichloro-diethyl-sulphide. In seawater, mustard gas hydrolyses slowly to thiodiglycol (which is non-toxic) and HC1 which is neutralized in seawater. It was manufactured in two forms, as mustard gas itself and as viscous mustard gas to which thickeners had been added. The viscous material can incorporate sand and m u d particles from the seafloor to make a more solid mass which further hinders the release of the mustard gas. Approximately 20% of the mustard gas was in the viscous form. In this form, hydrolysis is possible only after the mustard gas has diffused out of the viscous material and can take many years. Clark I and II are diphenyl arsine chloride and

cyanide, respectively. They hydrolyze to produce tetra-phenyldiarsine oxide which cannot be detoxified by further hydrolysis and may be preserved on the sea floor for many years. Adamsite is phenarsazine chloride. It is sparingly soluble in seawater and hydrolyses slowly to phenarsazinic oxide. Again, this compound cannot be detoxified by further hydrolysis and may be preserved on the sea floor for many years. Chloroacetophenone (mace) is 2-chloro-1phenylethanone. It hydrolyses extremely slowly in seawater. Phosgene is carbonyl chloride. It is broken down rapidly in seawater to CO 2 and HC1. Nitrogen mustard is trichlomethin. It hydrolyses much slower than mustard gas to produce non-toxic compounds. Tabun is P - c y a n o - N , N - d i m e t h y l phosphoramid acid ethyl ester. It dissolves rapidly and hydrolyses to H 3 P O 4 and H C N which further hydrolyses to H C O O H . These agents break down in sea water at varying rates to less toxic, water soluble compounds and do not pose long-term threats to the marine environment. The exceptions are viscous mustard gas which can be found as large lumps long after

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being released from the shells and Clark I and II and adamsite which hydrolyze to form compounds that contain arsenic. These can persist in the marine environment for a long time.

5. Dangers The main threats of chemical warfare agents which have been dumped in the sea are: 1. To the general public from agents washed ashore. This could only take place as a result of material in wooden crates being thrown overboard from moving vessels during the original dumping operation. Such occurrences were reported on Polish beaches, mainly between 1952 and 1955 and resulted in a number of injuries (Andrulewicz, 1994; Korzeniewski, 1994). 2. To fisherman trawling lumps of viscous mustard gas from the sea floor with their nets. Although the largest amount of chemical agents were dumped in the Bornholm Basin and this is clearly marked on nautical charts, the area continues to be fished. Fishermen still recover bombs, shells and lumps of mustard in their nets. Since 75% of the fishermen there are Danish, they have been the most affected. In the period between 1976 and 1992, 439 reports of recovery of chemical warfare agents were made equivalent to a catch rate of approximately 0.02% (Anon, 1993a). Under Danish law, catches contaminated by chemical agents must be destroyed. Several serious incidents involving Polish fishermen have also taken place (Andrulewicz, 1994; Korzeniewski, 1994). Only injuries but not deaths have been reported. All injuries to fishermen have occurred when liquid or solid mustard gas or viscous mustard gas have escaped from rusted munitions and come into contact with the skin. The mustard can penetrate clothing or rubber gloves and causes severe blistering of the skin and irritates the eyes and throat. It is considered doubtful that fish contaminated by chemical agents could reach the consumer. 3. To the marine environment. Many of the

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chemical agents are sparingly soluble so that toxic concentrations in sea water could not develop. The more soluble compounds, such as phosgene and tabun break down to nontoxic products. The main problems are lumps of viscous mustard gas. However, these do not cause the concentration of mustard gas in sea water to increase to dangerous levels and mustard gas has never been detected in sediments and waters taken nearby. Hydrolysis of mustard gas is very slow below 14°C because it is a solid below this temperature. Bottom waters in the Baltic Sea are below this temperature for most of the year (Matth~ius and Franck, 1992). Clark I and II and adamsite hydrolyse to form compounds that contain arsenic which would persist in sea water. Assuming that the Clark I and II and adamsite were dumped in the Baltic in the proportions that they were manufactured in Germany (approx. 8% of the total) and the weighted average amount of arsenic in them is approximately 27%, it can be calculated that the maximum amount of arsenic that may have been released into Baltic sea water from these weapons is approximately 280 t. The natural concentration of arsenic in Baltic sea water is approximately 1 ppb (Anon, 1993a). It can therefore be calculated that the maximum amount of arsenic that could be released into Baltic sea water is just over 1% of the total amount of naturally occurring arsenic in the Baltic sea water at any one time. Local enrichment of arsenic in the sediments would be possible. However, bioaccumulation of arsenic in marine organisms or enrichment in adjacent sediments above background level (100 ppm) have not been detected so far (Anon, 1993a). There have also been no reports of bioaccumulation of toxic agents in marine organisms in the Baltic or of poisoning of fish due to the presence of chemical warfare agents (Anon, 1993a). In spite of the relatively optimistic picture painted by western scientists (Anon, 1993a), Russian opinion appears much more negative. The metal casings of the disposed bombs and mines

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are known to be 70-80% rusted through. It was suggested that there could be a massive gas infiltration in European waters within the next few years which will have not only toxic but also genetic effects (Anon, 1994). Russian interest in this topic is demonstrated by the fact that two research cruises were undertaken in 1994 and 1995 by the All-Russian Geological Institute of St. Petersburg to investigate this problem as part of the Marine Ecological Patrol. In May 1990, a warning signal was given when a massive amount of poisoned crabs, mussels and over 6 million jellyfish were washed ashore in the White Sea off northern Russia (Anon, 1994). At first, this was thought to be the effect of mustard gas but was later attributed to sulphide-containing industrial waste water as well as highly toxic propellant for strategic sea-launched rockets. However, it is now known that 50-60 railway wagons full of lewisite aerial bombs were dumped in the Russian North Sea (Anon, 1994).

6. Dealing with the problem It is clear that the methods for disposing of the chemical warfare agents in the Baltic Sea at the end of WWII were unsatisfactory and would hopefully not be adopted today. Under no circumstances can the Baltic Sea be considered a suitable repository for such toxic material. The only excuse is that the discovery of chemical warfare agents in such quantities in Germany at the end of the war must have presented a major dilemma for the allies at a time when many other problems appeared more pressing. Nonetheless, the disposal of these agents is an object lesson in the folly of short-term solutions to environmental problems. There are three possible ways of dealing with this legacy: 1. collection of the shells and disposing of them on land, possibly after incineration of the chemical agents; 2. collection of the shells, setting them in concrete and dumping of them in the deep Atlantic; or 3. leaving them where they are.

Of these, the latter appears to be the only realistic option. The shells are corroded to varying degrees and it would be dangerous to bring them to the surface. Furthermore, gases contained in some of the shells may still be under pressure which could lead to rupturing of the shells and release of the chemicals on bringing them to the surface. Although leaving the shells where they are is not without risks, these are less than those involved in any other viable option. However, because of uncertainties about the status of these weapons and the paucity of work carried out so far, it has been suggested that a monitoring programme should be undertaken to assess the risks more precisely (Anon, 1993a; HELCOM, 1994). It may seem surprising that the disposal of chemical weapons in the Baltic Sea 50 years ago is attracting interest once again. This merely illustrates the dangers of poorly planned disposal of very toxic material and the uncertainties of the environmental outcome even decades later. Yet, in spite of the obvious dangers of stockpiling chemical weapons, they are still found in large quantities. Russia claims to have 40 000 t of them and the USA 31000 t (Anon, 1996). The USA is now disposing of its chemical weapons by incineration at plants on Johnston Atoll in the central Pacific and in Tooele, Utah, and plans to build seven more plants. The cost of the American disposal programme is estimated to be $US9 billion. In 1899, the use of asphyxiating gases in war was repudiated by representatives of 26 countries in the Hague. It would be nice to think that 1999 would see the ratification of the Chemical Weapons Convention and hopefully the virtual elimination of these weapons of mass mortality.

Acknowledgements This article is based largely on documents supplied by the Bundesamt fiir Seeschiffahrt und Hydrographie (BSH), Hamburg. I would particularly like to thank Drs N.P. Riihl and N. Theobald, BSH, Dr E. Andrulewicz, Sea Fisheries Institute, Gdynia, Poland, Drs S.M. Chilev and V.A. Zhamoida, St. Petersburg, Russia, and Dr H. B~cker,

G.P. Glasby /The Science of the Total Environment 206 (1997) 267-273 GEOMAR, Kiel, f o r s u p p l y i n g d o c u m e n t s vant to this study.

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