In popular imagination the power contained in the nucleus can only be utilized to generate energy. However, nuclear engineering is an important field that is proving to be useful from water purification to medicine. Potential application of irradiation and radioactivity is not limited to electricity production. There is a wide range of areas where peaceful atom plays an essential role. Diagnosis and treatment of medical conditions, space exploration, agriculture, archaeology and exploration of chemical and biological processes – the list is by no means exhaustive.
An operation to rescue the mummy of Ramesses II is a good illustration to the point. The Cairo Museum that keeps the mummy discovered in 1974 that it had started to decay. To eliminate a fatal outcome, the Mummy was urgently taken to France for which it had to be issued a current Egyptian passport. The Egyptian citizen, and king by profession (albeit deceased), was given an official welcome at the Paris airport with ceremony and brass music. A subsequent medical inspection revealed that the patient had been infected with bacteria, fungi and worms. The Mummy was subjected to penetrating radiation which destroyed the dangerous microbes and helped preserve a valuable exhibit item.
Chemical reactions taking place in irradiated water are known to decompose harmful organic substances and kill pathogenic germs. This also helps obtain better transparency and flavor and – most importantly – disinfect the water. Treatment of that kind does not develop radioactive substances in water or, unlike chlorination, any chemically toxic substances.
Similar treatment is given to waste discharged by agricultural, industrial, livestock breeding and utility companies. Their waste can contain anything! Toxic organisms found in it have to be decomposed, parasitic worms eliminated, and water in general has to be disinfected. Irradiation helps here, too, demonstrating better efficiency compared to traditional methods. Irradiation is also applied to gas emissions, specifically combustion gases from electric power stations. Given that harmful emissions and disposals are quite often not treated in any way before they get into the environment, irradiation proves a relatively cheap solution to some environmental issues.
Nuclear engineering can produce clear water for farming in places where it is scarce like in Africa. What can we do about it? If the sea is nearby, a nuclear station built on the shore can desalinate sea water. There are several options, and the simplest of them is this. Excess heat emitted by the reactor – not used in electricity generation – can evaporate salt water. Given that steam is free from salt – it only has to be condensed.
One of the key targets for the food sector is the extension of product’s shelf life. A great deal of food has to be dumped because it rots at storehouses and during transportation. In addition, the quality of food that gets to our dinner tables, specifically fish and meat, is often doubtful.
It can contain harmful bacteria, and the problem gets out of control given the scale of food nowadays produced and consumed. Irradiation can help – but another problem is bound to arise here as many people have vague fears about irradiated food and believe it can ‘accumulate’ radiation and transmit it to their system. Nothing could be farther from the truth.
Food’s nutritional value is affected by irradiation no more than by traditional treatment by heating. As regards toxic substances that could result from irradiation, there are no grounds to be concerned. Radioactive substances are not generated in food products through irradiation, because its energy is too weak to transform stable atoms into radioactive. It is only sufficient for the formation of chemically active particles that kill pathogenic bacteria – so food is sterilized without being boiled.
It has been proved time and again by experiments that irradiated products are harmless. By combining irradiation with thermal sterilization we can lower the irradiation dose and shorten thermal treatment time – which is a fairly cost-efficient solution. Food irradiation has long been used by many countries. As an example, Indian spices contain a lot of bacteria that can cause serious conditions, and that is why they get irradiated.
Irradiation can be applied to not only food, but also to instruments and materials that must be sterile. We are now talking of medicine and pharmaceutics: the likelihood of infection in medical procedures is much higher compared to daily life situations.
No one wants to be poked in their bodies with dirty or infected instruments. Irradiation can help sterilize medical appliances (blood transfusion stations, syringes, needles, etc.), drugs and implants.
Irradiation makes them perfectly clean without any side effect for people’s health. It is a widely used sterilization method, even for the conservation of biological transplants for ‘tissue banks’ that often mitigate the consequences of mass incidents, such as natural disasters, catastrophes, military conflicts or terrorist acts.
Irradiation is widely used in agriculture. It helps eliminate pests and bacteria from seeds for sowing. In some cases irradiation improves their germination rate, albeit very modestly.
Irradiation can be used for selection purposes to breed mutated varieties that are more resistant to weather conditions. This is how more productive varieties of rice, cotton and other plants have been bred. The word ‘mutant’ generally has a negative connotation, but here it is hardly justifiable because irradiation ‘adjusts’ the genes of mutated plants and improves their qualities, so any concerns that irradiation can be ‘communicated’ to man are futile.
In addition to breeding better plants, we have to fight pests that can destroy our harvests. We can bring the number of insects down to a safe level by using irradiation to sterilize them and then setting them free. Irradiated pests retain activity but are unable to reproduce. This method has been successfully applied to eliminate meat flies and Mediterranean fruit flies. Work in this field is under way with a new target in the crosshairs – namely, insects that carry dangerous diseases.
(The authors are Senior Lecturers of Russia`s Saint Petersburg State Institute of Technology).