Not all chemical weapons are stockpiled on land, Gorbachev points out. After World War II many countries rid themselves of their chemical arms by simply dumping them into the North Sea. Some 40,000 tons are sitting on the sea bottom, waiting to leak or to enter the marine food chain. There was also dumping in the Baltic after the last war by Germany and, to a lesser degree, by Russia and other countries. These immersed chemical weapons are particularly dangerous, because the Baltic sea is shallow.
Fishermen regularly find shells containing mustard gas in their nets and are badly burned.
Such incidents are common. Other chemical weapons also include arsenic, which could leak into the food chain. Established in Geneva in 1993, Green Cross International consists of 26 national organizations from every continent.