What Lies Beneath: A Plea for Complete Information Despite the large quantities of chemical weapons disposed of in the ocean from 1946 to 1972, offshore dumping sites have not been mapped or assessed adequately. PETER G. BREWER MONTEREY BAY AQUARIUM RESEARCH INSTITUTE NORIKO NAK AYAMA UNIVERSITY OF TOKYO
dre amstime /rhonda saunders
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recent C&EN article (1) on the 10th anniversary of the Chemical Weapons Convention reports that “around the globe more than 50,000 tons of declared chemical weapons await destruction.” Neither the U.S. nor Russia will likely be able to meet the deadlines imposed by the treaty. Unfortunately, when only the weapons on land are considered, we grossly underestimate both the quantity and the timescale. Although it may be true that this quantity awaits active destruction under the terms of the treaty, far larger quantities of chemical weapons await passive environmental degradation in the deep sea, primarily by slow hydrolysis in cold seawater. Confusion surrounding this topic, lack of meaningful observation, inadequate record keeping and reporting, and active avoidance of the subject matter have all contributed to the neglect of this important environmental issue. Chemical weapons disposal at sea occurred from 1946 until the signing of the London Convention in 1972. Although the convention, which was established through the UN International Maritime Organization (IMO), forbade further dumping, it did not establish criteria for site identification, monitoring, or reporting. And despite considerable and ongoing debate within IMO and efforts to create databases, very little of this information has been communicated to the scientists who go to sea and make ocean measurements. It thus appears that current policy is an inverted form of “don’t ask, don’t tell”: scientists have not asked for information about chemical weapons disposal sites, and the responsible agencies have felt no pressure to provide it. In a recent article (2), the locations and known quantities of chemical weapons sites off the U.S. East Coast were listed. No mention is made of the sites in the Pacific Ocean, yet the locations cover very large areas off the coast of California. In this article, as a simple case study, we compare the information available for sites in the Pacific Ocean, off the U.S. West Coast and the east coast of Japan, with information from better-studied sites in the Adriatic Sea. Although the distinction between the tonnage of munitions and the quantity of chemical agent is sometimes unclear, it is widely reported (3, 4) that 50,000–150,000 tons of munitions were disposed of in the Baltic Sea; that ~5000 tons of agent were disposed of at seven sites off the east coast of Japan (5); that ~150,000 tons of munitions have been disposed of in the White, Barents, and Kara seas of the Russian Arctic; and that 32 chemical weapons disposal sites exist off U.S. shores, the contents of which are complex and poorly documented. Possibly the best-studied sites are those in the Adriatic Sea, where several sunken ships off the harbors of Bari and Molfetta, Italy, have unequivocally been © 2008 American Chemical Society
leaking primary and degraded chemical weapons agents into the marine environment, causing direct harm to the ecosystem (6). Since 1946, ~500 humans have been injured— some very seriously—by inadvertent contact with chemical weapons disposed of in the ocean in the years after World War II (3, 4) until at least the 1970s. Almost all of the injured have been fishermen; none appear to have been ocean scientists who routinely sample the water column, often within a few meters of the seafloor, in most of the known dumping areas, without regard for or knowledge of the disposed materials. It is clear from many conversations with scientists on both sides of the Pacific Ocean that there is a huge lack of awareness of this issue.
Since 1946, ~500 humans have been injured— some very seriously— by inadvertent contact with chemical weapons disposed of in the ocean. The reasons for this are clear: the subject matter is distasteful and distinct from the ethos of uncovering the vast natural and now-changing cycles of the planet. In addition, an unfounded legacy of secrecy exists. Although the U.S. sites are plainly marked on nautical charts, today the norm for expedition planning is to rely on geophysical maps, satellite images, and model output. Few ocean scientists closely inspect conventional navigation charts (e.g., those produced by the National Oceanic and Atmospheric Administration [NOAA]) when planning their cruise tracks. Thus, sampling programs are usually planned without any consideration of the disposal sites. The topic typically is not covered in the mainstream ocean science journals, and ocean scientists who have ventured into this field usually have constructed abstract models but have not applied them to any real-world situations (7).
Background Toward the end of World War II and in the years afterward, the armed forces of the warring nations faced the problem of disposing of large quantities of chemical munitions—primarily mustard (1,1′-thiobis[2chloroethane]), lewisite ([2-chloroethenyl]arsonous dichloride), sarin (methylphosphonofluoridic acid, [1-methyl] ester), and tabun (dimethylphosphoramidocyanidic acid, ethyl ester). March 1, 2008 / Environmental Science & Technol ogy ■ 1395
The ocean was available, disposal was rapid and cheap, and few questions were asked. It was simply a matter of expedience; no governing regulations were in place, and record keeping was poor. As a result, large-scale dumping occurred in U.S. waters and at numerous sites around the world. Concern grew, and in the late 1960s, a committee of the U.S. National Academy of Sciences recommended alternative strategies for the disposal of chemical weapons, including withdrawal and incineration of the agents. For coffins containing sarin-filled rockets, ocean disposal was still considered a possible option and was used. FIGURE 1
Locations of hydrographic stations in the southern Adriatic Sea close to known sites Ocean sampling transects in the Adriatic Sea pass very close to known disposal sites off the towns of Bari and Molfetta. Unplanned scientific encroachment into such areas around the world is common. Station locations are taken from the National Oceanographic Data Center’s database. The disposal sites are taken from Amato et al. (6 ).
primary agent can be significant. A detailed account is given in the 1997 Measurements of Earth Data for Environmental Analysis report (3, 4), and the following brief descriptions are based on that data. Almost all of the information presented here is based on laboratory studies extrapolated to the environment; few actual site studies have been published because of the obvious hazards of direct investigation. Almost all of the information presented here relates to studies in normal oxygenated seawater; information about waters with lower pH and often anoxic sediment pore waters where material may be buried is scarce at best. When mustard is disposed of in seawater, water attacks the sulfonium ion, opening the ring to produce hemimustard, which then yields thiodiglycol and 1,4-thioxane in a ratio of roughly 4:1. Given the high solubility of the glycols, the presence of 1,4thioxane and related compounds (such as 1,4-dithiane) is a good indicator of degraded mustard around a disposal site. The initial hydrolysis of lewisite to toxic 2-chloro-vinylarsenous acid and lewisite oxide is quite rapid and eventually leads to the production of the various forms of arsenic found in the environment. Thus, a halo of complex and toxic arsenical compounds may be expected to form around a disposal site and migrate in pore water or groundwater (8); human poisoning from this also has been reported on land (9). Sarin is miscible with water and undergoes rapid hydrolysis to produce fluoride (as HF) and isopropylmethylphosphonate, which are highly soluble. Tabun hydrolyzes to form cyanide and monoethyldimethylphosphoramidate as the initial products and eventually converts to dimethylamine and phosphoric acid. Thus, mustard and lewisite degradation products are the most likely to be long-lived species.
The Adriatic experience
The London Convention was signed in 1972, largely because of concerns about the dumping of such weapons at sea, and ocean dumping was brought to an end. However, by then a formidable chemical legacy had been established at offshore sites around the world.
Chemistry in seawater In seawater, chemical weapons agents undergo dissolution and hydrolysis. However, the lifetime of the 1396 ■ Environmental Science & Technology / March 1, 2008
As a case study we consider the experience in the Adriatic Sea, where >200 fishermen were hospitalized between 1946 and 1966 because of exposure to chemical weapons agents caught in their nets. In 1999, the Italian government requested that a survey be conducted to identify sites affected by chemical weapons and to evaluate the degradation of material and the resulting ecotoxicological impacts (6). An acoustic side-scan survey identified 102 targets, and visual inspection by a remotely operated vehicle (ROV) revealed the leakage of chemical weapons agents through holes and fractures in the casings. The surrounding sediments had elevated levels of the mustard degradation products 1,4-thioxane and 1,4-dithiane, and locally caught fish exhibited lesions and contained levels of arsenic that exceeded the U.S. Food and Drug Administration’s limit for food. In Figure 1, we show the Adriatic dumping site (6) and compare it with locations of hydrographic stations occupied by ocean scientists, as drawn from the National Oceanographic Data Center’s database. In this region, the water column has been sampled routinely by ocean scientists, almost certainly with-
out regard to the disposed material; sediment coring locations are not shown in the database. We consider the Adriatic site as a leading indicator of degradation at other offshore locations where chemical weapons have been dumped: the warmer water will accelerate corrosion, the shallow depth will lead to increased contact with human and marine life, and the physical disruption as a result of contact with fishing gear will compromise the integrity of encasing materials. Thus, deeper, colder, and less battered sites should exhibit slower releases—but the materials eventually will corrode and leak into the ocean.
The California coast
and routinely monitored, is marked as a disposal site at this same location ~55 mi west of San Francisco. A second site is located ~120 mi west of the city at a depth of ~4200 m. It is very likely that this is the position of concern, but this site has never been surveyed and the location of these chemical weapons agents has not been identified. A third designated site is very close to the Channel Islands National Marine Sanctuary and a fourth is at the U.S.–Mexico border, where the U.S. Exclusive Economic Zone boundary line appears to have been drawn in a manner contrived to place the site within U.S. waters, despite its geographic location south of the border. No record of what may be present at either of these sites exists in the open literature.
Off the coast of California, between San Francisco and the TA B L E 1 Mexican border, seven sites that cover some 4000 mi2 of seaSites off the California coast designated as “Chemical Munitions floor—an area about the size of Dumping Area, Disused” on U.S. navigation charts the state of Delaware—are designated as “Chemical Munitions The locations given are the approximate centroids of each area. In total, ~11,952 km 2 of Dumping Area, Disused” (Taseafloor are identified as possibly containing disposed chemical weapons material. ble 1); these are quite separate Location Approximate Estimated Approximate from, but often confused with, description coordinates site area (km2) depth (m) the low-level nuclear waste site Off northern Mexico 31°38´ N 118°34´ W 259 2195 off the Farallon Islands. No Channel Islands 33°40´ N 118°34´ W 207 1920 chemical hazard symbols apOffshore Santa Maria 34°30´ N 122°15´ W 3108 420–4060 pear on nautical charts, and no useful record provides details of 3367 4390 Offshore Point Sur 36°20´ N 125°30´ W what was dumped at the seven Off Monterey Bay 37°00´ N 124°00´ W 1243 3658 sites. 3652 4206 Offshore San Mateo 37°30´ N 125°30´ W The sites are deeper than Off Farallon Islands 37°45´ N 123°25´ W 116 2560 those in the Adriatic Sea, and the water is colder; thus, degradation rates are slower. No human injuries or conThe “Chemical Munitions Dumping Area, Distacts have been reported, almost certainly because used” designation is so vague and the total area so of the great depth. It is unlikely that the sites have large that scientists typically disregard the inforbeen battered by fishing gear, and thus the contain- mation. This situation would be inconceivable on ing structures are more likely to be intact. However, land. The size of the site does not appear to be corthey inevitably will corrode. related with the quantity of material disposed of. The geometric shapes of the areas—rectangles and triangles—do not represent the typically ovoid shape The “Chemical Munitions that is characteristic of a deep-sea geochemical signal dispersed by ocean currents. Actual debris sites Dumping Area, Disused” are likely to be much smaller, possibly a factor of 10 less, than designated areas. designation is so vague The debris location and contaminated zone could be identified readily, and some realistic boundaries and the total area so large established; yet at this time, no such plans are under way or even being discussed.
that scientists typically
disregard the information. It has been reported (3) that in April 1958, the SS William Ralston was loaded with 1257 tons of lewisite and 301,000 M70 bombs containing mustard and sank with its loathsome cargo at “37°40′ N 125°0′ W about 55 statute miles west of San Francisco.” A similarly loaded barge also was sunk at this site. This is confusing because the well-known Farallons radioactive waste site, examined by the U.S. Geological Survey (http://geopubs.wr.usgs.gov/circular/c1198)
Japan’s east coast Sites off the east coast of Japan are small, shallow, and close to shore and contain thousands of tons of disposed chemical weapons agents (5). Although NOAA charts designate the unquantified California sites, the equivalent U.S. National Geospatial-Intelligence Agency charts of Japanese waters make no mention of the known Japanese disposal sites. This lack of designation is simply a matter of choice as to what level of detail to present. Scientists in the U.S. who are planning surveys from these charts would have no knowledge of the sites. March 1, 2008 / Environmental Science & Technol ogy ■ 1397
When the Japanese disarmed at the end of World War II, the stocks of chemical weapons were handed over to the U.S. occupation forces for disposal (5). The work was carried out by Japanese contractors under U.S. supervision, and disposal at sea was the method of choice. The standard was that sites should be >10 nautical miles from shore and >3000 ft deep; however, unknown to the U.S. forces, the Japanese Imperial Forces also disposed of chemical weapon materials privately. The record keeping was incomplete, disposal procedures were faulty, disposal sites were closer to shore than planned, and numerous accidents and injuries were reported.
ply because of this lack of awareness. For example, one U.S. research cruise, carried out as part of a contaminant baseline survey (10), mapped the distribution of As species in the North Pacific Ocean. The scientists surveyed deep-water stations but ceased to make measurements when the vessel was over the Japanese continental shelf. The cruise participants likely would have taken background measurements for these contaminants had they been aware of their presence.
Japanese Coast Guard, Choshi
Detection strategies
Chemical weapons casings containing mustard are snared in fishing gear off Choshi, one of the largest fishing ports in Japan. An employee of the Japanese Maritime Safety Agency, dressed in a hazmat suit, supervises the return of the contaminated material to its originally designated offshore site.
In the years that followed, many fishermen tragically encountered the disposed agents (see photo above), and in 1972 the Japanese Prime Minister requested an inquiry. That inquiry revealed seven authorized sites (5); however, the distribution of reported accidents suggested that unauthorized disposal activities had taken place outside of those authorized areas and that the depth and distance regulations had been violated. The clear signs of battering by fishing gear (see photo above) combined with numerous injuries to humans suggest that, in many cases, the weapons containers have been breached and that chemical agents have spilled onto the seafloor. The situation closely resembles that reported in the Adriatic, where fish with lesions and elevated levels of arsenical species have been found near disposal sites and mustard degradation products have been found in the surrounding sediments. Yet to our knowledge, no comprehensive mapping or ecotoxicological studies have been carried out to define the areas that are safe for harvesting seafood for human consumption. The affected areas are likely to be small. Japanese ocean scientists, as well as their California colleagues, have simply ignored this problem and sampled the ocean as they saw fit without regard for the chemical weapons disposal sites. They have little direct knowledge of relevant chemical signals, and, in many cases, have missed opportunities sim1398 ■ Environmental Science & Technology / March 1, 2008
The strategies for locating chemical weapons sites include side-scan sonar surveys, followed by visual location with ROV dives. The hazardous nature of the primary material makes it challenging to determine what contaminants are present. When containers have been breached and the primary agents are visible, noncontact in situ spectroscopic methods are often used. For example, Raman systems have been developed for the remote identification and analysis of complex matrices on the seafloor (11, 12). Most studies intended to identify undersea chemical weapons disposal sites involve the use of sophisticated calculations to predict the formation and detection of a water-column plume emitted from a site (2, 6). However, this approach appears to be impractical, and no such plume has ever been detected. Ocean scientists are skilled at detecting and mapping geochemical plumes emitted from the seafloor (13, 14). But these natural plumes are huge, with fluxes on the order of moles per minute; the detection of the small signals emitted from a disposal site with continuously changing current velocities is much more challenging. A more practical approach would be to examine sediment transport properties around the primary site. To our knowledge, no sediment transport studies have been carried out and published.
Can databases be compiled? Although the reported progress on the Chemical Weapons Convention (1) is gratifying, it is disturbing that so little is known about the vast quantities of chemical weapons disposed of on the seafloor. Some international and regional databases are being compiled, but the work has just begun. The danger to ocean scientists and fishermen alike is still very real until these efforts are completed and the results made widely known. We note that the intensity, scale, and manner of scientific sampling of the ocean have changed radically over recent decades and that contact with this materiel could occur easily. One such example arose in 1992 on Leg 146, Hole 889 of the U.S. Ocean Drilling Program (15). At a late date, a drilling site chosen from geophysical surveys was determined to be too close to a Canadian disposal site offshore of Vancouver Island. Sampling of the uppermost 20 m of the sediments was restricted as a result. This implied acknowledgment of materiel sinking into marine sediments strongly suggests that mapping of the sites will become more difficult as time goes
by and that interactions with marine sediments and pore waters will introduce new complexity into environmental prediction. Peter G. Brewer is a senior scientist at the Monterey Bay Aquarium Research Institute. Noriko Nakayama is an assistant professor at the Ocean Research Institute, University of Tokyo. Address correspondence about this article to Brewer at
[email protected].
Acknowledgment This work was supported by a grant to the Monterey Bay Aquarium Research Institute by the David and Lucile Packard Foundation.
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