1986 After almost 40 years of cover-ups, the U.S. Government released 19,000 pages of previously classified documents which revealed that the Hanford Engineer Works was responsible for the release of significant amounts of radioactive materials into the atmosphere and the adjacent Columbia River. Between 1944 and 1966, the eight reactors, a source of plutonium production for atomic weapons, discharged billions of gallons of liquids and billions of cubic meters of gases containing plutonium and other radioactive contaminants into the Columbia River, and the soil and air of the Columbia Basin. Although detrimental effects were noticed as early as 1948, all reports critical of the facilities remained classified. By the summer of 1987, the cost of cleaning up Hanford was estimated to be $48.5 billion. The Technical Steering Panel of the government-sponsored Hanford Environmental Dose Reconstruction Project released the following statistics in July 1990: Of the 270,000 people living in the affected area, most received low doses of radiation from Iodine, but about 13,500 received a total dose some 1,300 times the annual amount of airborne radiation considered safe for civilians by the Department of Energy. Approximately 1,200 children received doses far in excess of this number, and many more received additional doses from contaminants other than Iodine. [See also May 1997 and July 2000.]