Though irradiating food crops has several scientific benefits, opinion is divided about its long-term effect on human health
At a scientists-media interaction on ‘Radiation and Quality of Human Life’ organised by the Press Information Bureau (PIB) recently, experts from the Bhabha Atomic Research Centre (BARC) made presentations on the benefits of nuclear agriculture, radiation-processing of agricultural produce and medical application of radiation and its health effects.
Scientists say “radiation-induced mutation” or “mutational breeding” helps in specifically-targeted genetic variability. For example, an irradiation project on white ‘ponni’ rice might reduce the height of the plant so the stalks don’t droop or mature early. In soyabean, it might reduce phytic acid, an anti-nutritional factor and on green gram, it might improve disease resistance. Radiation on black gram may make it suitable for rice fallows, in tapioca, it might modify starch properties. Crops will also become thermo-tolerant.
So, do I look for a “radiation glow” on my plate of idlis? I’m kidding, of course, but Atomic Energy Commission Chairman, Dr. Ratan Kumar Sinha, says every second idli in the country contains black gram harvested from seeds genetically modified by BARC. Atomic energy — radiation, in particular — is making a tremendous contribution to agriculture Through radiation and breeding, BARC has produced seeds of 41 kinds of crops, including pulses, rice, jute, sunflower and groundnuts which are drought-and-pest-resistant.
“Radiation from X-rays/gamma rays in agriculture will help produce new crop varieties,” adds C. R. Ananda Kumar, Director (i/c), Centre for Plant Breeding and Genetics, Tamil Nadu Agriculture University (TNAU). Radiation and isotopes can also be used to study absorption of nutrients, dis-infestation of stored grain, eradication of insects, and preservation of crops. In agricultural crops, the seeds are mostly irradiated and in horticultural crops, irradiation can also be done to vegetative parts or in-vitro cultures. Mutations are mainly done where variability is not available in the germ plasm. Irradiations are done in gamma irradiation chambers produced and supplied by Board of Radiation and Isotope Technology (BRIT), Mumbai.
How safe is all this? The radiation source is protected by two layers (lead and stainless steel), and there is no chance of a radiation leak outside the machine, says Dr. Ananda Kumar. “The radiation will not have any side-effect. Normally, we get cosmic rays from the sun every day.” Can everyone eat irradiated food? No harm in eating it, he says. When the food — in a packed condition — is exposed to radiation, it becomes free of micro-organisms. It is completely sterilised and can be stored for a long time.
Great, but radiation-induced mutation/breeding (mutagenesis) is a failed programme in terms of efficacy, says Tushar Chakraborty, molecular biologist, Council for Scientific and Industrial Research. “Called ‘Atoms for Peace’, this propaganda was launched in the late 1950s.” Asserting that the mutagenesis strategy is random, unpredictable and unsafe, he argues that the varieties created by this technique are in thousands, while the existing natural varieties run into millions. “Radiation-induced-variety-generation” (RIV) plants have replaced and wiped out gene banks of natural varieties.” He isn’t sure authenticated RIV crops are grown or marketed. “The method is to subject the plant genome to a high dose of radiation, and screen the damaged pool of plant germlines for plant breeding.”
“This is unnatural,” affirms Anantha Sayanan of Safe Food Alliance. Have there been studies into the side/after-effects of such technology on human health, and the environment? If ill-effects are connected directly to such imprecise technology, as in genetically modified (GM) food crops, reversing will be almost impossible.
The long-term health consequences of eating irradiated food are unknown, warns Dr. Sultan Ahmed Ismail, Director, Institute of Research in Soil Biology and Biotechnology, Chennai. In India and China, it has been found harmful. “Irradiation creates a complex series of reactions that alter the molecular structure of food, and may create substances whose impact is not known. Ionising radiation may create free radicals, and they may be present in the food we eat. Free radicals, however, are also formed when food is fried, baked, ground, and dried. Also, the Joint Food and Agricultural Organisation (FAO)/ International Atomic Energy Agency (IAEA)/WHO Expert Committee in 1981 concluded that irradiation of any food commodity upto an overall average dose of 10 kGy presents no toxicological hazard (Gy is the abbreviation for Gray, named after the British physicist Louis Gray. 1Gy=1joule/kg absorbed); hence, toxicological testing of food so treated is no longer required. So, stringent rules must be implemented on radiation dosages. Also, irradiation can prolong the quality of some perishable foods, but it cannot make decaying food fresh.
People are demanding labelling of irradiated food, he pointed out. “Will food engineered with technology appeal as “food” for consumption?”