Environmental hazards of sea-dumped chemical weapons

Environmental impact of the explosion of the Nord Stream pipelines

Armed conflicts have, in addition to severe impacts on human lives and infrastructure, also impacts on the environment, which needs to be assessed and documented. On September the 26th 2022, unknown perpetrators deliberately ruptured the two gas pipelines Nord Stream 1 and 2 with four coordinated explosions near a major chemical munition dump site near the Danish island of Bornholm in the Baltic Sea. While the massive release of natural gas into atmosphere raised serious concerns concerning the contribution to climate change-this paper assesses the overlooked direct impact of the explosions on the marine ecosystem. Seals and porpoises within a radius of four km would be at high risk of being killed by the shockwave, while temporary impact on hearing would be expected up to 50 km away. As the Baltic Proper population of harbour porpoises (Phocoena phocoena) is critically endangered, the loss or serious injury of even a single individual is considered a significant impact on the population. The rupture moreover resulted in the resuspension of 250000 metric tons of heavily contaminated sediment from deep-sea sedimentary basin for over a week, resulting in unacceptable toxicological risks towards fish and other biota in 11 km3 water in the area for more than a month.

Synthesizing the impact of sea-dumped munition and related chemicals on humans and the environment

Marine environments are globally impacted by vast quantities of munition disposed following both World Wars. Dumped munitions contain conventional explosives, chemicals warfare agents as well as a variety of metals. Field monitoring studies around marine dumpsites report the presence of munition constituents in water and sediment samples. The growing interest and developments in the ocean as a new economic frontier underline the need to remediate existing dumpsites. Here, we provide a comprehensive assessment of the magnitude and potential risks associated with marine munition dumpsites. An overview of the global distribution of dumpsites identifying the most impacted areas is provided, followed by the currently available data on the detection of munition constituents in environmental samples and evidence of their toxic potential to human and environmental health. Finally, existing data gaps are identified and future research needs promoting better understanding of the impact of the dumped material on the marine environment suggested.

Metagenomic Analysis of the Gastrointestinal Microbiota of Gadus morhua callarias L. Originating from a Chemical Munition Dump Site

Several hundred thousand tonnes of munitions containing chemical warfare agents (CWAs) are lying on the seafloor worldwide. CWAs have started leaking from corroded munitions, and their presence in the environment and in organisms inhabiting dump sites has been detected. The presence of CWAs in the water negatively affects fish, macrobenthos and free-living bacteria. It can be expected that the presence of CWAs would also affect the gut-associated bacteria in fish, which are vital for their condition. The main aim of this study was to test if the microbiota of cod collected in the Baltic Bornholm Deep (highly polluted with CWAs) is dysregulated. To investigate this, we conducted metagenomic studies based on 16S rRNA gene sequencing. We found that the microbiota of cod inhabiting the dump site was significantly less taxonomically diverse compared to those from a non-polluted reference site. Moreover, taxa associated with fish diseases (e.g., Vibrionaceae, Aeromonadaceae) were more prevalent, and probiotic taxa (e.g., Actinobacteriota, Rhodobacteraceae) were less frequent in the guts of individuals from the dump site, than those from the reference site. The differences in vulnerability of various bacterial taxa inhabiting cod gastrointestinal tracts to CWAs were hypothesised to be responsible for the observed microbiota dysregulation.

The use of historical evidence in studies on underwater munitions

Marine scientists and other experts depend on information found in archival documents and other historical records to investigate underwater munitions. These sources help them locate dumpsites, establish timelines, identify ordnance, and better understand the hazards, chemicals, and degradation products found in their studies. However, historical sources do not always satisfy these needs, and can sometimes lead investigators down convoluted, incomplete, and misleading trails of evidence. This article seeks to provide scientists with some advice about conducting archival research and interpreting meaning from historical sources by recounting the history of a dumping operation that never happened over the summer of 1921. In doing so, this article demonstrates the value of historical perspectives and research methodologies, and encourages scientists to better integrate historical evidence into their work and seek out more collaborative opportunities with historians.

Acute aquatic toxicity of arsenic-based chemical warfare agents to Daphnia magna

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems. The aim of this research was to support a need for real-data measurements for accurate risk assessments and categorization of threats originating from submerged CWAs. This has been achieved by providing a broad insight into arsenic-based CWAs acute toxicity in aquatic ecosystems. Standard tests were performed to provide a solid foundation for acute aquatic toxicity threshold estimations of CWA: Lewisite, Adamsite, Clark I, phenyldichloroarsine (PDCA), CWA-related compounds: TPA, arsenic trichloride and four arsenic-based CWA degradation products. Despite their low solubility, during the 48 h exposure, all CWA caused highly negative effects on Daphnia magna. PDCA was very toxic with 48 h D. magna LC50 at 0.36 μg × L^-1 and Lewisite with EC50 at 3.2 μg × L^-1. Concentrations at which no immobilization effects were observed were slightly above the analytical Limits of Detection (LOD) and Quantification (LOQ). More water-soluble CWA degradation products showed no effects at concentrations up to 100 mg × L^-1.

Acute aquatic toxicity of sulfur mustard and its degradation products to Daphnia magna

Sulphur mustard (HD) was the most widely produced chemical warfare agent (CWA) in the history of chemical warfare (CW). Simultaneously, the loads of HD account as by far the largest fraction of the sea-dumped CW. Nowadays its presence in the marine ecosystems recognized as a serious threat for marine users and maritime industries. Although, during over a decade of research much has been done to assess the environmental threats linked with underwater chemical munitions. There are, however, essential gaps in scientific knowledge including scarce information about the aquatic toxicity thresholds of HD and its degradation products. Standardized biotests were performed according to the Organisation for Economic Co-operation and Development (OECD) Test No. 202: Daphnia sp. Acute Immobilisation Test guidelines. Obtained results provide a solid foundation for comparison and categorisation of threats of HD and its degradation products. With the D. magna LC₅₀ aquatic acute toxicity threshold at as low as 224 ± 12 μg × L^-1, 1,2,5-trithiepane is very toxic, being one of the most toxic CWA degradation products that have been investigated up to date. It exhibits stronger effects than 1,4,5-oxadithiepane and diluted HD that turn out to be toxic. In total, the toxicity of 7 compounds has been estimated. Whenever possible, toxicity thresholds were compared with previously existing data originating from different biotests and mathematical modelling.

Marine bivalves as bioindicators for environmental pollutants with focus on dumped munitions in the sea: A review

The seas worldwide are threatened by a "new" source of pollution. Munitions dumped into the seas worldwide will corrode and start to leak. Their impacts on the environment and on human health are now more than ever subject of scientific research. Bivalves are a first choice bioindicator and their importance is demonstrated in numerous worldwide studies as well as their integration in important monitoring programs. In this review, the use of mussels in context with marine pollutants in recent years is pointed out in general but with a special focus on dumped conventional and chemical munitions. Monitoring experiments with mussels are able to generate large data sets, which should be mandatory included in decision support tools to increase their weight of evidence. The usefulness of mussels with regard to dumped munitions has clearly been documented in recent years and the further application of this important biomonitoring system is strongly recommended.

Induction of nuclear abnormalities in herring (Clupea harengus membras), flounder (Platichthys flesus), and Atlantic cod (Gadus morhua) collected from the southern part of the Gotland Basin-the Baltic Sea (2010-2017)

Eight nuclear abnormalities of genotoxicity and cytotoxicity were studied in peripheral blood erythrocytes of herring (Clupea harengus membras), flounder (Platichthys flesus), and Atlantic cod (Gadus morhua) sampled (2010-2017) from the Polish and the Lithuanian Exclusive Economic Zones (EEZ) in the Baltic Sea. At all study stations, total genotoxicity (∑Gentox) was found to be higher than total cytotoxicity (∑Cytox). A significant time-related decrease in genotoxicity was detected in the Lithuanian EEZ (2015-2017), while in the Polish EEZ (2014-2016), the opposite tendency was revealed. The highest ∑Gentox and ∑Cytox values recorded in fish sampled at the study stations located relatively close to each other clearly indicate an increased environmental genotoxicity and cytotoxicity pressure for fish in these areas. Exceptionally high and high-level genotoxicity risks to herring followed by those to flounder and cod were determined at a higher percentage of the stations studied.

Environmental genotoxicity and cytotoxicity levels in herring (Clupea harengus), flounder (Platichthys flesus) and cod (Gadus morhua) inhabiting the Gdansk Basin of the Baltic Sea

Frequencies of eight nuclear abnormalities (NAs) reflecting environmental genotoxicity and cytotoxicity, were examined in 739 specimens of herring (Clupea harengus), flounder (Platichthys flesus) and cod (Gadus morhua) collected between 2009 and 2017 at 50 study stations located in the Gulf of Gdansk and the southern part of the Gdansk Deep (the Baltic Sea). The highest levels of geno-cytotoxicity were recorded in fish caught at stations located in close proximity to chemical and conventional munitions dumping sites or in zones polluted by Chemical Warfare Agents (CWAs). The values of NAs were significantly higher (up to 51-fold compared with the reference level) in herring caught at seven stations and in cod from one station located close to the munitions dumping sites. Exceptionally high total genotoxicity (∑Gtox) risk was found for flounder collected from 18 (72.0%) stations, herring caught at 12 (38.7%) stations and cod caught at four (17.4%) studied stations.

Deep sea habitats in the chemical warfare dumping areas of the Baltic Sea

The Baltic Sea is a severely disturbed marine ecosystem that has previously been used as a dumping ground for Chemical Warfare Agents (CW). The presence of unexploded underwater ordnance is an additional risk factor for offshore activities and an environmental risk for the natural resources of the sea. In this paper, the focus is on descriptions of the marine habitat based on the observations arising from studies linked to the CHEMSEA, MODUM and DAIMON projects. Investigated areas of Bornholm, Gotland and Gdańsk Deeps are similarly affected by the Baltic Sea eutrophication, however, at depths greater than 70m several differences in local hydrological regimes and pore-water heavy metal concentrations between those basins were observed. During the lifespan of presented studies, we were able to observe the effects of Major Baltic Inflow, that started in December 2014, on local biota and their habitats, especially in the Bornholm Deep area. Reappearance of several meiofauna taxa and one macrofauna specimen was observed approximately one year after this phenomenon, however it's ecological effects already disappeared in March 2017. According to our findings and to the EUNIS Habitat Classification, the three reviewed areas should be characterized as Deep Sea Muddy Sands, while the presence of suspicious bomb-like objects both beneath and on top of the sediments confirms their CW dumpsite status.

Ecotracer: analyzing concentration of contaminants and radioisotopes in an aquatic spatial-dynamic food web model

Ecotracer is a tool in the Ecopath with Ecosim (EwE) software package used to simulate and analyze the transport of contaminants such as methylmercury or radiocesium through aquatic food webs. Ecotracer solves the contaminant dynamic equations simultaneously with the biomass dynamic equations in Ecosim/Ecospace. In this paper, we give a detailed description of the Ecotracer module and analyze the performance on two problems of differing complexity. Ecotracer was modified from previous versions to more accurately model contaminant excretion, and new numerical integration algorithms were implemented to increase accuracy and robustness. To test the mathematical robustness of the computational algorithm, Ecotracer was tested on a simple problem for which we know an analytical solution. These results demonstrated the effectiveness of the program numerics. A much more complex model, the release of the cesium radionuclide ¹³⁷Cs from the Fukushima Dai-ichi nuclear accident, was also modeled and analyzed. A comparison of the Ecotracer results to sampled ¹³⁷Cs measurements in the coastal ocean area around Fukushima show the promise of the tool but also highlight some important limitations.

Petroleum oil and mercury pollution from shipwrecks in Norwegian coastal waters

Worldwide there are tens of thousands of sunken shipwrecks lying on the coastal seabed. These potentially polluting wrecks (PPW) are estimated to hold 3-25milliont of oil. Other hazardous cargo in PPW includes ordnance, chemicals and radioactive waste. Here, we present and discuss studies on mercury (Hg) and oil pollution in coastal marine sediment caused by two of the >2100 documented PPW in Norwegian marine waters. The German World War II (WWII) submarine (U-864) lies at about 150m below the sea surface, near the Norwegian North Sea island of Fedje. The submarine is estimated to have been carrying 67t of elemental Hg, some of which has leaked on to surrounding sediment. The total Hg concentration in bottom surface sediment within a 200m radius of the wreckage decreases from 100g/kgd.w. at the wreckage hotspot to about 1mg/kgd.w. at 100m from the hotspot. The second wreck is a German WWII cargo ship (Nordvard), that lies at a depth of ca. 30m near the Norwegian harbor of Moss. Oil leakage from Nordvard has contaminated the bottom coastal sediment with polycyclic aromatic hydrocarbons (PAH). The findings from this study provide useful insight to coastal administration authorities involved in assessing and remediating wreck-borne pollution from any of the tens of thousands of sunken shipwrecks.

Transient receptor potential (TRP) channels as molecular targets in lung toxicology and associated diseases

The lungs as the gateways of our body to the external environment are essential for gas exchange. They are also exposed to toxicants from two sides, the airways and the vasculature. Apart from naturally produced toxic agents, millions of human made chemicals were produced since the beginning of the industrial revolution whose toxicity still needs to be determined. While the knowledge about toxic substances is increasing only slowly, a paradigm shift regarding the proposed mechanisms of toxicity at the plasma membrane emerged. According to their broad-range chemical reactivity, the mechanism of lung injury evoked by these agents has long been described as rather unspecific. Consequently, therapeutic options are still restricted to symptomatic treatment. The identification of molecular down-stream effectors in cells was a major step forward in the mechanistic understanding of the action of toxic chemicals and will pave the way for more causal and specific toxicity testing as well as therapeutic options. In this context, the involvement of Transient Receptor Potential (TRP) channels as chemosensors involved in the detection and effectors of toxicant action is an attractive concept intensively discussed in the scientific community. In this review we will summarize recent evidence for an involvement of TRP channels (TRPA1, TRPC4, TRPC6, TRPV1, TRPV4, TRPM2 and TRPM8) expressed in the lung in pathways of toxin sensing and as mediators of lung inflammation and associated diseases like asthma, COPD, lung fibrosis and edema formation. Specific modulators of these channels may offer new therapeutic options in the future and will endorse strategies for a causal, specifically tailored treatment based on the mechanistic understanding of molecular events induced by lung-toxic agents.

Accumulation of intact sulfur mustard in adipose tissue and toxicokinetics by chemical conversion and isotope-dilution liquid chromatography-tandem mass spectrometry

Sulfur mustard (SM) is a powerful vesicant and one of the most harmful chemical warfare agents. Although having been studied for a long time, it is still difficult to fully elucidate the mechanisms of SM poisoning, and there is no effective antidote or specific treatment for SM injury. The investigations on toxicokinetics and tissue distribution of SM will help to understand its toxicity and provide a theoretical basis for pretreatment and therapy of SM poisoning. But the metabolic trajectory or fate of intact SM in vivo remains unclear, and there are insufficient experimental data to elucidate, due to its high reactivity and difficulty in biomedical sample analysis. In this paper, a sensitive method for the detection and quantification of intact SM in blood or tissues using isotope-dilution LC-MS/MS coupled with chemical conversion was developed. By transforming highly reactive SM into stable derivative product, the real concentration of intact SM in biological samples was obtained accurately. The toxicokinetics and tissue distribution studies of intact SM in rats were successfully profiled by the novel method after intravenous (10 mg/kg) or cutaneous administration (1, 3 and 10 mg/kg). The SM level in blood with peak time at 30-60 min determined in cutaneous exposure experiment was found much higher than previously reported, and the mean residence time in blood extended to 1-1.5 h. A significant accumulation of intact SM was observed in adipose tissues, including the perirenal fat, epididymal fat, subcutaneous fat and brown fat, in which the concentrations of SM were at least 15 times greater than those in non-adipose tissues in cutaneous exposed rats. The recovery of SM in body fat was calculated as 3.3 % of bioavailable SM (the bioavailability after cutaneous exposure was evaluated as 16 %). Thus, the adipose tissue was important for SM distribution and toxicity, which may pioneer a new model for both the prevention and treatment of SM exposure.

Environmental genotoxicity assessment along the transport routes of chemical munitions leading to the dumping areas in the Baltic Sea

The frequencies of micronuclei (MN), nuclear buds (NB) and nuclear buds on filament (NBf) were examined in 660 specimens of herring (Clupea harengus) collected in 2009-2014 at 65 study stations located mainly along the chemical munition transport routes in the Baltic Sea. The frequency of nuclear abnormalities was strongly increased in herring caught at four stations located close to chemical munition dumping sites, or CWAs - substances (chemical warfare agents) in sediments. Significant increase of MN, NB and NBf was observed in fish caught November 2010-2013 compared to 2009. The most significantly increased genotoxicity responses were recorded in fish caught at stations along CW (chemical weapons) transport routes, close to the Bornholm CW dumping area, in zones with CWAs in sediments and with oil-gas platforms.

Sea-dumped chemical weapons: environmental risk, occupational hazard

INTRODUCTION

Chemical weapons dumped into the ocean for disposal in the twentieth century pose a continuing environmental and human health risk.

OBJECTIVE

In this review we discuss locations, quantity, and types of sea-dumped chemical weapons, related environmental concerns, and human encounters with sea-dumped chemical weapons.

METHODS

We utilized the Ovid (http://ovidsp.tx.ovid.com) and PubMed (http://www.pubmed.org) search engines to perform MEDLINE searches for the terms 'sea-dumped chemical weapons', 'chemical warfare agents', and 'chemical munitions'. The searches returned 5863 articles. Irrelevant and non-English articles were excluded. A review of the references for these articles yielded additional relevant sources, with a total of 64 peer-reviewed articles cited in this paper. History and geography of chemical weapons dumping at sea: Hundreds of thousands of tons of chemical munitions were disposed off at sea following World War II. European, Russian, Japanese, and United States coasts are the areas most affected worldwide. Several areas in the Baltic and North Seas suffered concentrated large levels of dumping, and these appear to be the world's most studied chemical warfare agent marine dumping areas. Chemical warfare agents: Sulfur mustard, Lewisite, and the nerve agents appear to be the chemical warfare agents most frequently disposed off at sea. Multiple other type of agents including organoarsenicals, blood agents, choking agents, and lacrimators were dumped at sea, although in lesser volumes. Environmental concerns: Numerous geohydrologic variables contribute to the rate of release of chemical agents from their original casings, leading to difficult and inexact modeling of risk of release into seawater. Sulfur mustard and the organoarsenicals are the most environmentally persistent dumped chemical agents. Sulfur mustard in particular has a propensity to form a solid or semi-solid lump with a polymer coating of breakdown products, and can persist in this state on the ocean floor for decades. Rates of solubility and hydrolysis and levels of innate toxicity of a chemical agent are used to predict the risk to the marine environments. The organoarsenicals eventually breakdown into arsenic, and thus present an indefinite timeline for contamination. Generally, studies assaying sediment and water levels of parent chemical agents and breakdown products at dumpsites have found minimal amounts of relevant chemicals, although arsenic levels are typically higher in dumpsites than reference areas. Studies of marine organisms have not shown concerning amounts of chemical agents or breakdown products in tissue, but have shown evidence of chronic toxicity. There is believed to be minimal risk posed by seafood consumption. Microbiota assays of dumpsites are significantly altered in species composition compared to reference sites, which may imply unseen but significant changes to ecosystems of dumpsites. Human health concerns: The major human health risk at this time appears to arise from acute exposure to an agent by either accidental recovery of a chemical weapon on a fishing vessel, or by munitions washed ashore onto beaches.

CONCLUSIONS

Improving technology continues to make the deep sea more accessible, thus increasing the risk of disturbing munitions lying on or buried in the seabed. Pipe laying, cable burying, drilling, scuba diving, trawling, and undersea scientific research are the activities posing the most risk. The long-term threat to the benthic habitat via increased arsenic concentrations, shifts in microbiota speciation, and chronic toxicity to vertebrates and invertebrates is not currently understood. The risk to the environment of massive release via disturbance remains a distinct possibility. Terrorist recovery and re-weaponization of chemical agents is a remote possibility.

Review of environmental exposure concentrations of chemical warfare agent residues and associated the fish community risk following the construction and completion of the Nord Stream gas pipeline between Russia and Germany

This paper compiles all the measured chemical warfare agent (CWA) concentrations found in relation to the Nord Stream pipeline work in Danish waters for the past 5 years. Sediment and biota sampling were performed along the pipeline route in four campaigns, prior to (in 2008 and 2010), during (in 2011) and after (in 2012) the construction work. No parent CWAs were detected in the sediments. Patchy residues of CWA degradation products of Adamsite, Clark I, phenyldichloroarsine, trichloroarsine and Lewisite II, were detected in a total of 29 of the 391 sediment samples collected and analyzed the past 5 years. The cumulative fish community risk quotient for the different locations, calculated as a sum of background and added risk, ranged between 0 and 0.017 suggesting a negligible acute CWA risk toward the fish community. The added risk from sediment disturbance in relation to construction of the pipelines represents less than 2% of the total risk in the areas with the highest calculated risk. The analyses of benthic infauna corroborate the finding of CWA related low risk across the years. There was no significant difference in CWA risk before (2008) and after the pipeline construction (2012).

Past 140-year environmental record in the northern South China Sea: evidence from coral skeletal trace metal variations

About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986-1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities.

Environmental hazard of yperite released at sea: sublethal toxic effects on fish

The aim of this study was to evaluate the potential toxicological effects on fish related to the leakage of yperite from rusted bomb shells dumped at sea. Both in vivo and field studies have been performed. As for the in vivo experiment, specimen of European eel were subcutaneously injected with 0.015, 0.15 and 1.5mg/kg of yperite and sacrificed after 24 and 48 h. In the field study, specimen of Conger eel were collected from a dumping site in the Southern Adriatic Sea. The presence/absence of yperite in tissues, genotoxicity, detoxification enzymes, histological alterations and gross abnormalities were investigated. Results of the in vivo experiment showed a significant increase of EROD activity at both 24h and 48 h. UGT activity increased significantly at 48 h post injection. An acute inflammatory response after 24h in skin layers and muscle was observed, associated to cell degeneration and necrosis after 48 h at the highest dose. On field, comet assay revealed genotoxicity in gills of fish from the dumping site. Specimen from the dumping site showed significantly higher EROD activities compared to controls, deep ulcers and papules on skin together with liver and spleen histopathological lesions.

Weight-of-evidence environmental risk assessment of dumped chemical weapons after WWII along the Nord-Stream gas pipeline in the Bornholm Deep

In connection with installation of two natural gas pipelines through the Baltic Sea between Russia and Germany, there has been concern regarding potential re-suspension of historically dumped chemical warfare agents (CWA) in a nearby dump site and the potential environmental risks associated. 192 sediment and 11 porewater samples were analyzed for CWA residues, both parent and metabolites in 2008 and 2010 along the pipeline corridor next to the dump site. Macrozoobenthos and background variables were also collected and compared to the observed CWA levels and predicted potential risks. Detection frequencies and levels of intact CWA found were low, whereas CWA metabolites were more frequently found. Re-suspension of CWA residue-containing sediment from installation of the pipelines contributes marginally to the overall background CWA residue exposure and risk along the pipeline route. The multivariate weight-of-evidence analysis showed that physical and background parameters of the sediment were of higher importance for the biota than observed CWA levels.