The 6th anniversary of Three Mile Island, March 28, 1985, received more U.S. press attention than the worst radiation spill in North America which is slowly killing more than 200 Mexican citizens.
Eight years ago, a group of doctors at the Centro Medico, in Juarez, Mexico, bought a cancer therapy unit, the Picker 3000, from an x-ray equipment company in Fort Worth, Texas. Under Mexican law, the Picker 3000 should have been registered with the country’s National Commission for Nuclear Safety and Safeguards, but wasn’t. Instead, the unit was abandoned in an empty warehouse for seven years until late December, 1983, when a local worker removed a tungsten wheel from the unit to sell as scrap. The wheel contained the unit’s radioactive source: 6010 tiny pellets each containing 70 microcuries of cobalt-60. The worker sold the unit to a nearby junk dealer for ten dollars. At the junk yard, the wheel was picked up with an electromagnet and scattered the pellets throughout the yard. The spill was undetected. The yard’s 60 employees and every piece of metal in the yard was dusted with lethal doses of radiation. Later, when one of the town citizens parked a pick-up truck from the junkyard in his driveway, some 200 citizens in Juarez also were contaminated with a lethal dose of cobalt60. They received significant doses of gamma radiation ranging from 1 to 50 rem. (The highest exposure a bystander at Three Mile Island could have received was about 100 millirem, or a tenth of a rem.).
Most of the contaminated scrap metal and pellets were trucked 220 miles south of Juarez to a smeltering plant. The metal was then melted down, contaminating more than 5000 tons of steel. An estimated 700 tons was contracted for use in kitchen table legs and reinforcement beams some of which entered the U.S. (When discovered, there was a brief flurry of publicity which died down after U.S. NRC officials said they believe that any metal trucked into this country has been returned to Mexico for burial.)
Much of the remaining 4300 tons of contaminated steel was used for foundation supports in homes throughout Mexico. But all this metal may never retrieved, according to some officials who propose to recycle the metal for use in dams and bridges, where human exposure is considered minimal. Another popular idea among NRC officials and Mexican nuclear officials is to build nuclear power stations with the beams.
The entire tragedy might never have been known if it hadn’t been for an accidental event. A truck delivering some of the contaminated steel bars to a construction site in the Los Alamos National Lab, New Mexico, made a wrong turn and headed past a radioactive materials control station, tripping off the alarm. What is now known is that the sixty junkyard employees are expected to die of cancer or leukemia and an estimated 200 other citizens in Juarez are also expected to die or display signs of cancer or leukemia within the next few years. And the crisis is not over, for not all of the spilled material has been accounted for, and some Mexicans are still being irradiated unknowingly.
SCIENCE, Vol. 223, 3/16/84, “Juarez: An Unprecedented Radiation Accident,” by Eliot Marshall, pp 1152-1154; GUARDIAN, 6/20/84, “Worst Radiation Spill in North America’ Still Spreading,” by Robby Newton and Ellen Kahaner, p 17.