Mexico's El Cobalto

Response and cleanup crews sometimes face public health dangers much more immediate than ten years down the line. This was the case in December 1983, when a twenty-year-old radiation therapy machine ended up abandoned in a Juarez, Mexico, warehouse. Handyman Vincente Sotelo, while trans- porting the device to a junkyard, took an unmarked capsule from the machine. Upon later prying it open, he found that it contained more than six thousand tiny pellets of radioactive cobalt-60. Some of these pellets spilled out to contaminate Sotelo's pickup truck and then local streets. Other pellets re- mained in the capsule while it was sold as scrap, mixed with metals, and shipped to two Mexican foundries. One foundry thus inadvertently made radioactive metal table legs and the other radioactive steel reinforcement rods ("rebar").

It was more than a month later before a truck...