Sea-dumped chemical weapons: environmental risk, occupational hazard

Area of Science:

• Marine environmental science
• Environmental toxicology
• Chemical oceanography

Background:

• Twentieth-century ocean dumping of chemical weapons presents ongoing environmental and human health risks.
• Significant quantities of chemical munitions were disposed of at sea globally, particularly off the coasts of Europe, Russia, Japan, and the United States.

Purpose of the Study:

• To review the locations, quantities, and types of sea-dumped chemical weapons.
• To discuss associated environmental concerns and human health risks.
• To highlight the potential for accidental encounters and ecosystem disruption.

Main Methods:

• Comprehensive literature search using Ovid and PubMed with keywords 'sea-dumped chemical weapons', 'chemical warfare agents', and 'chemical munitions'.
• Inclusion of 64 peer-reviewed articles after excluding irrelevant and non-English publications.
• Review of references from initial search to identify additional relevant sources.

Main Results:

• Sulfur mustard and Lewisite are among the most common agents dumped, with persistence concerns for sulfur mustard due to its polymer coating.
• Organoarsenicals break down into arsenic, posing long-term contamination risks.
• While direct chemical agent levels in sediment and water are often minimal, arsenic concentrations are higher at dumpsites, and marine microbiota show significant alterations.

Conclusions:

• Deep-sea accessibility increases the risk of disturbing buried chemical munitions through activities like drilling and trawling.
• Long-term threats include arsenic contamination, altered benthic habitats, and chronic toxicity to marine life.
• The potential for large-scale agent release and the remote possibility of re-weaponization remain significant concerns.