This is the VOA Special English Environment Report.
The Baltic Sea is home to thousands of tons of old chemical weapons. Britain, the Soviet Union and the United States captured these from Nazi Germany. The Allies thought the best thing to do was to sink them, sometimes on ships, after World War Two. Poisons like arsenic, sarin and mustard gas are among the weapons in the Baltic. Some bombs and shells under the sea date back to World War One.
Scientists say damage caused by the water has permitted poisons to leak out of their containers. Some are mixing with sand and other sea material. Thick and sticky balls of mustard gas have formed. Fishing crews have pulled up bombs and shells. Some people have suffered chemical burns.
Fishing boats do not always obey restricted areas. Nor do they always know where weapons are located.
The Helsinki Commission is an intergovernmental group that supervises the Baltic Sea environment. The commission has published guidelines on how fishing boats can avoid risky areas. These also advise fishing crews what to do if they pull up weapons. Included is medical advice and information on how to clean boats after such an incident.
But, the commission says the weapons do not harm the Baltic Sea in any measurable way. It says current information suggests there is no risk to plants or animals in the sea. And, it says there is no evidence that poisons have gotten into seafood for humans.
The commission says the best way to deal with the weapons is to leave them alone. It says time will destroy what remains. It argues that attempts to remove or contain them are riskier than leaving them under the sea where they may be buried under sand.
But not all scientists agree. Some say the situation is too risky to leave alone. Vadim Paka is the director of the Institute of Oceanography in Kaliningrad, Russia. He says any highly poisonous substance in the Baltic Sea system is dangerous. Mister Paka says the situation requires more study. He says failing to so could lead to tragedy.
Other waters around the world also hold weapons. But some people say the Baltic Sea may be at greater risk. It is only fifty meters deep on average. And it is a major shipping area with many people living along its coasts.
This VOA Special English Environment Report was written by Caty Weaver.