Radiation Processed Food: A Big Challenge & Opportunity

‘Radioactive food’ can send a chill down to anyone’s spine. The accident at the Chernobyl (Ukraine) nuclear power station occurred on April 26, 1986. Thereafter, radioactive fallout has shown up in food commodities in various countries. The nuclear crisis at Fukushima Daiichi Nuclear Power Plant in Japan has caused a fresh scare.

There is radioactivity (manmade and natural) in all food commodities. The common radionuclides in food are potassium, radium and uranium. The world is covered in cesium-137 from the atomic weapons tests of the ‘50s and ‘60s. It’s really a matter of saying how much? 

While “nuclear dual use” is a term that is often used for peaceful or military aims, in case of food chain it could be a choice between destruction and preservation. While contaminated food with radioactive material can create havoc, radiation processing (called irradiation) of the food involves a controlled application of energy from ionizing radiations for food preservation. 

In natural conditions during sun drying, a large number of commodities get heavily contaminated with microbes including pathogenic bacteria from deposition of excreta of insects, birds, rodents and other animals and from windblown dust containing these microbes. It can also lead to caking and spoilage. Insect infestation is another major problem in stored commodities often resulting in losses up to 20-25%. All these can be controlled through irradiation which is a far superior technology than chemical preservation. It works by disrupting the biological processes that lead to decay without compromising on the nutritional and health factors. 

In countries like France, Netherlands, South Africa, US, Thailand and China, commercial quantities of some radiation processed food items — strawberries, mango, banana, shrimp, chicken, spices — are sold on the market shelf. These radiation processed food items are labelled to indicate the treatment and its purpose. 

The WHO has established limits that serve as guidelines for governments. Radioactive material in food is measured in Becquerels (Bq). The limit for iodine-131 is 55 Bq per kilogram for infant food and 300 Bq per kilogram for other foods. For meat and poultry the limit is 55 Bq per kilogram. The limit for cesium-134 and cesium-137 for all food items is 370 Bq per kilogram. 

After the Fukishama nuclear plant leak, the Food Safety and Standards Authority of India in an order has instructed its units at ports to ensure that sample tests are conducted to the products shipped out of Japan after March 11. Initially, three BRIT/BARC laboratories at Trombay (Mumbai), Kolkata and Kalpakkam were accredited to conduct test and certification for radioactivity in the food samples sent to them. By a recent notification two more private labs in Delhi & Chennai have been accredited by AERB (Atomic Energy Regulatory Board) to conduct such tests.

In case of nuclear leaks, what really happens is that the radioactive iodine from food and air can build up in the thyroid, leading to thyroid cancer years later. Radioactive iodine decays quickly, with a half-life of eight days, meaning the length of time it takes for half of it to break down harmlessly. Young children and pregnant women could be at greatest risk. The other element, radioactive cesium can build up throughout the body and is harder to eliminate and high levels are thought to be a risk for various cancers. Cesium can stay in the soil for 30 years, however the radiation stays only in the top inches of soil, so deep plowing can make a field safe to use.

Controlling radioactive leakage (contaminated with radionuclides) after a nuclear disaster is a challenge for many nations; on the other hand “irradiation” opens up new vistas in food commodity preservation. 

Published in The Economic Times