There are no really historical records of the volume and type of material that was spilled in the oceans before the establishment of an anti-dumping law. However, it is estimated that in 1968, 38 million tons of excavated material, 4.5 million tons of industrial waste, 4.5 million sewage sludge, 100 million tons of petroleum-based product (plastic), 2 to 4 tonnes of chemical waste, more than 1 million tons of heavy metals were released into the ocean. The U.S. archive shows that between 1946 and 1970 over 55,000 containers of radioactive waste were disposed in 3 sites of dumping of the Pacific Ocean. In addition, 34,000 tons of radioactive wastes were disposed in 3 sites of dumping of the U.S. east coast between 1951 and 1962. No law on dumping radioactive waste has been put into force before 1972.