On Dec. 2, gunmen at a gas station commandeered a private truck that was carrying a heavy piece of cancer-treating machinery from a hospital in Tijuana to a radioactive waste storage facility near Mexico City. The theft set off global alarm bells, including an alert from the Vienna-based International Atomic Energy Agency, which described the highly radioactive cobalt-60 that had powered the missing equipment as “extremely dangerous.”

Then, within two days, fears subsided that the material could be used for a “dirty bomb” if it fell into the hands of terrorists. Mexican officials announced that the material had been located and that the suspected thieves had been arrested.

Except in the town of Hueypoxtla, a village 35 miles northeast of Mexico City, where the hospital machinery and a tube containing the 60 grams of cobalt-60 came to rest in a cornfield, where they remained for days.

Villagers in Hueypoxtla wondered why no one came to claim the cobalt. Federal police kept a security cordon around an area that appeared to be close to a half-mile square in size. Farmers were blocked from tending their fields. No official offered an explanation. The lack of information unsettled townspeople.

They grew antsy, even irate.

At an open-air meeting one night this week they hounded Mayor Francisco Santillan.

“If there are 60 grams of cobalt around here, why don’t they take it away?” implored Roberto Ramirez Bravo, a schoolteacher who had grabbed a microphone.

As Santillan tried to answer, shouts of “Liar! Liar!” rang out.

Finally, late Tuesday, Mexico’s Secretariat of Energy released a three-paragraph statement saying that authorities had, at last, succeeded in using a robot to place the cobalt-60 in a shielded container and removing it from the field.

In a telephone interview Wednesday, Mexico’s nuclear safety director, Juan Eibenschutz, flatly rejected complaints that authorities were slow in removing the cobalt-60, saying that they had done so “in world record time.” He said Mexico’s rules on transfer of radioactive material are adequate and that any shortcomings that led to the robbery were the fault of a contractor, not the government.

“We’ll have to see what measures we take, but the regulations are good,” he said.

But the way the cobalt-60 incident was handled raises a host of questions about Mexico’s ability to manage radioactive materials and underscores how little faith Mexicans have in their government officials.

Even as authorities warned that the thieves could die within a day if exposed directly to the nuclear material, they spent a week puzzling over what to do about the cobalt-60 as the material sat abandoned in the field outside of town. Who extracted the cobalt-60 from the medical machinery and left it in the field remains unknown. None of the six people detained in relation to the theft of the truck tested positive for radiation exposure.

A truck driver, Mauro Moya, dragged the heavy metal machine – without the missing cobalt-60 – from the field to his yard.

“I thought it was a water pump that was broken,” he said. “I couldn’t read the English label.” He said he reckoned the metal was valuable. “I figure that’s worth 2,000 pesos ($155). That’s enough for a week or two of our household expenses.”

A hospital exam later showed that he didn’t suffer radiation exposure.

The casing was still in his yard Tuesday night.

“The government will never tell us the truth,” said Maria de Lourdes Perez, a 50-year-old farmer, fretting over whether radiation would give cancer to the grandson walking at her side.

Santillan, the mayor, called townspeople for a public meeting Tuesday at dusk in a semi-built recreation facility near the cornfield. Hundreds arrived in a testy mood that grew downright angry when police briefly barred reporters.

“We are trying to do things as responsibly as possible. Believe me,” Santillan said. “We can’t be playing with human lives.”

“Let the press in,” one man shouted. “Let everyone know what is going on,” another voiced. After a few minutes, police allowed a knot of journalists to pass through a mesh fence, although one was already inside.

“The soil, the crops and the land … are not contaminated,” Santillan said.

The radiological security director from the National Commission for Nuclear Safety, Jaime Aguirre Gomez, appeared shaken by the anger of the crowd.

“The situation is almost under control,” Aguirre said.

A retired school principal, Raul Cardenas, interjected. “Don’t go telling us that nothing has happened here,” he said. “I want to know when you are going to resolve this… . Tell us when your robot and your people will take this stuff away.”

Cardenas turned to the crowd and asked if townspeople would agree with a pressure tactic – taking over a four-lane federal highway near Hueypoxtla.

“Do you agree with this?” he asked the crowd. “Si!” came the response.

The misplacement or loss of cobalt-60, which has many applications in radiotherapy in hospitals and in industry, has caused a furor in Mexico before.

In late 1983, a scrap yard in Ciudad Juarez, across the border from El Paso, Texas, obtained a medical radiation unit containing 6,010 small, silvery cobalt-60 pellets that looked like cake decorations. When the scrap yard disassembled the equipment, the pellets were sent to foundries and factories where they were mixed into what became steel rebar, table pedestals and other products, some of which were exported to the United States.

The problem wasn’t discovered until a truck carrying rebar took a wrong turn into the Los Alamos National Laboratory in New Mexico one day in January 1984, setting off radiation sensors.

Retrieving the contaminated metal took months, and some of it was found in restaurant tables in active use in U.S. restaurants. Mexican authorities demolished 109 houses built with the radioactive rebar.

The latest incident showed that weaknesses remain in the transport and disposal of radioactive waste in Mexico. The truck carrying the material from Tijuana did not have a functioning GPS system, and the truck was stolen from a driver who was roused at a gas station while taking a nap in the 2.5-ton truck’s cab.

Mexico’s principal radioactive waste disposal site is not far from where the latest mishap occurred – outside the village of Santa Maria Maquixco in the state of Mexico.

Guarded by a high white fence, it bears a sign for the National Institute of Nuclear Research. Villagers nearby contend that the facility is unsafe.

“The radiation affects a lot of people with cancer and leukemia. Many people want to leave,” said Julio Escobar Rodriguez, the village chief said, making a common assertion.

Escobar said 20,000 people live in 14 communities within a several-mile radius of the waste site.

“There’s so much desert in this country, like in Sonora. Why don’t they take it there?” he asked, referring to the waste.