Iridium 192 is used as a source of gamma radiation for the treatment of cancer using ‘brachytherapy’, a form of radiotherapy where a sealed radioactive source is placed inside or next to the area requiring treatment. The Oncology department of the hospital had been using the material since 2002 to treat cancer patients. According to medical physicist Pradhumna Prasad Chaurasiya, in order to replace the ‘iridium’ it has to be sent back to Belgium every four months. The lost iridium was the 33rd one imported from the country.

“We had sent the material following due procedure,” Chaurasiya claimed. The iridium, weighing 15 kilograms, was placed inside a white container with a radiation logo. “The material, if exposed to humans, is life threatening and can pose serious health risks,” said the physicist.

The hospital has issued a notice urging the public to inform police if they knew the whereabouts of the material.

“The radio-active material can affect a whole settlement,” said Bhakta Man Shrestha, chairperson of the hospital. A person exposed to radiation can develop skin or blood cancer, and even die on the spot, Shrestha said. The hospital on Wednesday sought help from the District Administration Office. “The driver of the vehicle has been arrested and is being probed,” said Ujjwal Shrestha, director of Swift Cargo. In an e-mail sent to the hospital, Ujjwal has assumed the material may have been lost en route from Narayangadh to Kathmandu.