Fate and effects of Composition B in multispecies marine exposures

How contaminated is flatfish living near World Wars' munition dumping sites with energetic compounds?

Seas worldwide are threatened by an emerging source of pollution as millions of tons of warfare materials were dumped after the World Wars. As their metal shells are progressively corroding, energetic compounds (EC) leak out and distribute in the marine environment. EC are taken up by aquatic organisms and pose a threat to both the marine ecosphere and the human seafood consumer because of their toxicity and potential carcinogenicity. Here, sediment samples and fish from different locations in the German North Sea of Lower Saxony were examined to determine whether EC transfer to fish living close to munition dumping areas. EC were found in sediments with a maximum concentration of 1.5 ng/kg. All analyzed fish muscle tissues/fillets and bile samples were positive for EC detection. In bile, the max. EC concentrations ranged between 0.25 and 1.25 ng/mL. Interestingly, while detected TNT metabolites in the muscle tissues were in concentrations of max. 1 ng/g (dry weight), TNT itself was found in concentrations of up to 4 ng/g (dry weight). As we found considerable higher amounts of non-metabolized TNT in the fish muscle, rather than TNT metabolites, we conclude an additional absorption route of EC into fish other than per diet. This is the first study to detect EC in the edible parts of fish caught randomly in the North Sea.

Environmental Characterization of Underwater Munitions Constituents at a Former Military Training Range

As a result of military activities, unexploded ordnance and discarded military munitions are present in underwater environments, which has resulted in the release of munitions constituents including the high explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), along with their primary degradation products, to the water column and adjacent sediments. The present study focused on the characterization of underwater exposure and concentrations of energetics such as TNT and RDX at the former Vieques Naval Training Range at Bahia Salina del Sur (Vieques, Puerto Rico, USA), a bay with documented high incidence of munitions. In situ passive sampling using polar organic chemical integrative samplers (POCIS) was used for the detection and quantification of constituents in water at target locations approximately 15 to 30 cm from 15 individual potentially leaking munitions, and also at 15 unbiased locations approximately evenly spaced across the Bay. For comparison with POCIS-derived concentrations, grab samples were taken at the POCIS target locations. The POCIS-derived and averaged grab samples agreed within a factor of 3. When detected, munitions constituent concentrations (primarily TNT and RDX) were observed at ultratrace concentrations (as low as 4 ng/L for RDX), except 30 cm from one General Purpose bomb where the TNT concentration was 5.3 µg/L, indicating that low-level contamination exists at Bahia Salina del Sur on a very localized scale despite the relatively high density of munitions, similar to previously reported results for other munitions sites around the world. Sediment and porewater sampled at 4 stations where munitions constituents were detected in the water column had concentrations below detection (approximately 5 µg/kg and 5 ng/L, respectively), suggesting that the sediment was not a sink for these constituents at those locations. Environ Toxicol Chem 2022;41:275-286. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

"Don't Blast": blast-in-place (BiP) operations of dumped World War munitions in the oceans significantly increase hazards to the environment and the human seafood consumer

The seas worldwide are threatened by a "new" source of pollution: millions of tons of all kind of warfare material have been dumped intentionally after World War I and II, in addition to mine barriers, failed detonations as well as shot down military planes and sunken ship wrecks carrying munitions. For example, in the German parts of the North and Baltic Sea approximately 1.6 million metric tons of toxic conventional explosives (TNT and others) and more than 5000 metric tons of chemical weapons are present. Such unexploded ordnance (UXO) constitutes a direct risk of detonation with increased human access (fisheries, water sports, cable constructions, wind farms and pipelines). Moreover, after more than 70 years of resting on the seabed, the metal shells of these munitions items corrode, such that chemicals leak out and distribute in the marine environment. Explosive chemicals such as TNT and its derivatives are known for their toxicity and carcinogenicity. In order not to endanger today's shipping traffic or the installation of pipelines and offshore plants by uncontrolled explosions, controlled blast-in-place (BiP) operations of these dangerous relics is a common practice worldwide. However, blast-in-place methods of in situ munitions disposal often result in incomplete (low-order) detonation, leaving substantial quantities of the explosive material in the environment. In the present free field investigation, we placed mussels (Mytilus spp.) as a biomonitoring system in an area of the Baltic Sea where BiP operations took place and where, by visual inspections by scientific divers, smaller and larger pieces of munitions-related materials were scattered on the seafloor. After recovery, the mussels were transferred to our laboratory and analyzed for TNT and its derivatives via gas chromatography and mass spectroscopy. Our data unequivocally demonstrate that low-order BiP operations of dumped munitions in the sea lead to multiple increases in the concentration of TNT and its metabolites in the mussels when compared to similar studies at corroding but still encased mines. For this reason, we explicitly criticize BiP operations because of the resulting environmental hazards, which can ultimately even endanger human seafood consumers.

Release of Munitions Constituents in Aquatic Environments Under Realistic Scenarios and Validation of Polar Organic Chemical Integrative Samplers for Monitoring

Munitions constituents (MC) may be released into aquatic environments as a result of underwater military munitions (UWMM) corrosion and breach. The present study investigated the release of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) from Composition B fragments under 2 realistic exposure scenarios in a large flume with flow set at 15 cm/s: the first represented the release of MC from fully exposed Composition B, and the second represented release through a small hole, simulating a breached munition. Release of MC through a small hole was approximately 10 times lower than from exposed Composition B, demonstrating the strong influence of exposure to flow on release. The rate of release of MC into the flume was similar to that previously reported in a related field experiment, but a similar mass loss resulted in MC concentration in the field >300 times lower, likely by the dilution effect of hydrodynamic transport. The present study corroborates previous findings of release of MC at UWMM sites resulting in concentrations below the toxicity threshold to most species. In the flume water, MC was quantified using frequent grab sampling and polar organic chemical integrative samplers (POCIS). For TNT, POCIS-estimated time-weighted average concentrations were up to 40% higher than those derived from grab samples, whereas for RDX differences were 6% or less, demonstrating that POCIS provide reliable temporal integration of changing environmental concentrations for common MC. Environ Toxicol Chem 2019;38:2383-2391. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Field validation of POCIS for monitoring at underwater munitions sites

The present study evaluated polar organic chemical integrative samplers (POCIS) for quantification of conventional munitions constituents, including trinitrotoluene (TNT), aminodinitrotoluenes, diaminonitrotoluenes, dinitrotoluene, and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in a field setting. The POCIS were deployed at varying distances from the commonly used explosive formulation composition B (39.5% TNT, 59.5% RDX, 1% wax) in an embayment of Santa Rosa Sound (Pensacola, FL, USA). Time-weighted averaged water concentrations from a 13-d deployment ranged from 9 to 103 ng/L for TNT and RDX, respectively, approximately 0.3 to 2 m from the source. Concentrations decreased with increasing distance from the source to below quantitation limits (5-7 ng/L) at stations greater than 2 m away. Moderate biofouling of POCIS membranes after 13 d led to a subsequent effort to quantify potential effects of biofouling on the sampling rate for munitions constituents. After biofouling was allowed to occur for periods of 0, 7, 14, or 28 d at the field site, POCIS were transferred to aquaria spiked with munitions constituents. No significant differences in uptake of TNT or RDX were observed across a gradient of biofouling presence, although the mass of fouling organisms on the membranes was statistically greater for the 28-d field exposure. The present study verified the high sensitivity and integrative nature of POCIS for relevant munitions constituents potentially present in aquatic environments, indicating that application at underwater military munitions sites may be useful for ecological risk assessment. Environ Toxicol Chem 2018;37:2257-2267. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.