Mustard Gas Munitions Dredged Up by New Jersey Clam Boats

From CDC's Morbidity and Mortality Weekly Report*, "Notes from the Field." By Ryan Snead, Marija Borjan, Virginia Wheatley and Katharine McGreevy (New Jersey Department of Health) and Danielle Mills (CDC).*

Summary

• Known before: until 1970, unexploded chemical warfare munitions (CWMs), including sulfur mustard from both World Wars, were dumped at sea. Fishing boats occasionally dredge them up, endangering crews.
• What this adds: three incidents in New Jersey waters — 2016, 2017 and 2023 — caused severe injuries and the destruction of large amounts of seafood.
• What it means: the risk lasts as long as munitions lie on the seafloor. Avoiding known dump sites comes first, then engineering and administrative controls, interagency coordination, training and protective equipment.

Background

Until 1970, an estimated 17,000 tons of unexploded World War I and II chemical munitions — weapons meant to spread toxic agents — were dumped off the Atlantic coast. Dredging, which harvests animals from the seafloor, sometimes brings them up. Three such events hurt workers or contaminated food in the mid-Atlantic and New England in 2004–2012.

Six crew members were exposed in the three New Jersey events described here, all with injuries consistent with sulfur mustard — a blister agent that burns skin and mucous membranes on contact. The findings come from medical and billing records, poison control notes, agency correspondence and crew accounts. Shellfish processors cooperated fully in destroying food.

Three incidents

In every case, the Coast Guard's Atlantic Strike Team found no remaining contamination on the vessel.

An example of skin injured by sulfur mustard; it does not show anyone in this report. U.S. Air Force photo.

Conclusions

• Still a hazard: drift, storms and offshore industry mean munitions may lie far from documented dump sites.
• Overboard is still the safest choice for crews, since a dredged munition's stability is unknown — but it means it can be caught again.
• The law: munitions long underwater are generally treated as abandoned, not weapons, and U.S. law doesn't require their recovery or destruction.
• Coordination: responses involve the Coast Guard, FDA, state agencies and the fishing and seafood industry; strong communication can protect workers and prevent foodborne illness.

Prevention: avoid known dump areas; use containment and magnet-assisted sorting; adopt exposure-prevention policies; provide protective equipment and training. If a munition is suspected, follow the Recognize, Retreat, Report steps, including recording the location. Prompt care and reporting protect both workers and food.

Sources

Based on "Notes from the Field: Exposures to Chemical Munitions During Commercial Fishing" (New Jersey, 2016–2023), MMWR, Centers for Disease Control and Prevention; a work of the United States government in the public domain. It cites the U.S. Army's 2001 report on offshore disposal of chemical agents, a 2013 MMWR note on mid-Atlantic and New England exposures, a 2017 case report of a clammer's exposure, a 2024 Coast Guard marine safety alert, and the Defense Department's 3Rs explosive safety guide for the maritime industry.