Pollution of the open seas by human activities has become a serious problem. Ocean dumping is the dumping or placing of materials in designated places in the ocean, often on the continental shelf. A wide range of materials is involved, including garbage, construction and demolition debris, sewage sludge, dredge material, and waste chemicals. In some cases, ocean dumping is regulated and controlled, while some dumping occurs haphazardly by ships and tankers at sea, or illegally within coastal waters. Incineration at sea of organic wastes, with subsequent dumping, has been allowed as a viable disposal process, both in the United States and in Europe.
An important, but little recognized source of ocean dumping is the elimination of bilge water from tankers carrying oil and other products. Bilge water can contain a number of toxic chemicals, as well as biological agents that can affect marine ecosystems and marine organisms, some of which are subsequently consumed by humans. Dumping of radioactive wastes and soil from contaminated nuclear defense sites has periodically been suggested as a viable disposal method, and canisters of nerve gas have been disposed of at sea. In addition to permitted ocean dumping, there is always the possibility of collisions, groundings, and accidents that result in de facto ocean dumping, often of materials not otherwise allowed.
At one time, drums containing hazardous waste were dumped, but the disintegration of canisters caused sufficient concern to halt this process. Some of the drums containing hazardous chemicals were dumped in shallow seas, such as the North Sea, that are intensely fished, creating a potential risk to humans from the consumption of contaminated fish and shellfish.
A number of U.S. federal laws apply to at-sea incineration, including the Resource Conservation and Recovery Act, Toxic Substances Control Act, Water Pollution Prevention and Control Act, Air Pollution Prevention and Control Act, Dangerous Cargo Act, Ports and Waterways Safety Act, Deep Water Ports Act, and the Ocean Dumping Act. Most states also have a number of laws and regulations to control operations.
There are three main direct public health risks from ocean dumping: (1) occupational accidents, injuries, and exposures; (2) exposure of the public to hazardous or toxic materials washed up on beaches; and (3) human consumption of marine organisms that have been contaminated by ocean disposal. Periodically, medical and other wastes from both legal and illegal dumping have washed up on beaches, resulting in exposure to beachgoers and, in some cases, the closure of beaches until the wastes could be removed. Consumption of fish and shellfish contaminated from radioactive wastes may pose a serious problem worldwide because of nuclear waste dumping in the oceans.
One of the main sources of toxic chemicals off the Atlantic coast of the United States has been ocean-dumped municipal sewage sludge. In addition to biologic agents, sludge contains toxic residues. These same areas are fished heavily, both commercially and recreationally. From a public health perspective, pregnant women, women about to become pregnant, and young children are most at risk from the consumption of contaminated fish and shellfish.
JOANNA BURGER
