Burning bacteria

BRIT, set up to extend the frontiers of radiation technology, uses radioisotopes in a variety of ways.

FROM a facility shielded by a two-metre thick concrete wall, a conveyor belt-like system rolls out shipping cartons with polyester bags containing spices, herbal and ayurvedic raw material, onion powder, chillies, mustard and psyllum seed husk. The products have been irradiated to destroy harmful bacteria that may be present in them and extend their shelf life. From another machine rolls out shipping-cartons of pet food made of offal irradiated of bacteria such as Salmonella. This is exported to European countries.

The facility is the Board of Radiation and Isotope Technology (BRIT), located at Vashi, about 16 km from BARC. There is new excitement at BRIT: Indian mangoes treated with gamma radiation will be soon exported to the United States and Japan. The U.S. had banned the import of Indian mangoes as the fruits contain weevil. But irradiation has ensured the disinfestation of the beetle.

BRIT's radiation processing plant, "Krushak" (Krishi Utpadan Sanrakshan Kendra) in Nashik, is being upgraded for treating mangoes with gamma radiation. The facility's reach today is immense: it has made its presence felt in hospitals, industries, food preservation and in the fields of agriculture, hydrology and research. The radio-pharmaceuticals produced by BRIT are used in hospitals to diagnose and treat cancer of the cervix, breast, lung, thyroid, throat and blood.

Dr. A.K. Kohli, Chief Executive of BRIT, said: "The beneficial applications of radioisotopes and radiation technology constitute the most visible contributions of nuclear science and technology. Radioisotopes produced in research reactors, Dhruva and CIRUS, and many of the Pressurised Heavy Water Reactors find extensive applications in health care, industry, agriculture and research."

T.K. Jayakumar, Deputy General Manager, Quality Assurance and Isotope Application Services, BRIT, said radiation processing had "mind-boggling applications". BRIT was carved out of BARC on March 1, 1989, to take forward the frontiers of radiation technology. Radiation processing involves controlled application of energy of ionising radiation such as gamma rays, X-rays and accelerated electrons on products packed in polyester or gunny bags.

Credit for the export of BRIT's irradiated spices and pet feed should go to R.K. Sharma, who was its Senior Manager, Marketing. Sharma, who is now Head, Media Relations and Public Awareness Section, BARC, said the export of irradiated food had seen a steady rise.

Kohli said, "One of our prime-line activities is to set up radiation processing plants in the private sector." Five companies have already set up radiation processing plants, which are operating in Kolkata, Baroda, Ambarnath, Sonepat and Bangalore. They do radiation processing of spices and medical products. Three more plants in the private sector are under construction Hyderabad, at Vasai in Mumbai and Lasalgaon in Maharashtra. "Twelve more companies are planning to set up radiation processing plants," Kohli said.

ISOMED, set up in Trombay in 1974 by the DAE, has pioneered the radiation sterilisation technology. The plant irradiates medical and health care products by exposing them to gamma radiation. The products that undergo sterilisation at ISOMED include surgical knives, sutures and dressing, contraceptives, latex gloves, orthopaedic implants, antibiotic powders, ayurvedic powders and Dai kits.

In hydrology, radioisotopes are used, among other things, to detect seepage in dams, seawater intrusion into coastal aquifers, the movement of silt in harbour and estuaries and groundwater recharge and to trace the source of a dried-up river. In industry, radioisotopes are used for radiographing metals, for detecting minute leaks in underground oil and gas pipelines and for estimating the amount of oil left in an oil well after the well has been produced.