In addition, sediments in the bay are contaminated with PCBs, metals, and hydrocarbon fuels. A January 2005 edition of the Antarctic Sun, a U.S. National Science Foundation publication, noted that a former landfill located on a hill above the bay is considered to have been a primary source of the fuel and PCB contaminants. PCBs, now banned in the United States, were used in electrical and heating systems. A 1990 study found that PCBs in the water were also produced by marine shop wastes and ships pumping their bilges while docked.