An Ounce of Prevention
Preventing Plastic Pollution by using Radiation Processing
Long-lived plastic particles make up the vast majority of the trash floating in the world's oceans. (Photo: L. Potterton/IAEA)
- Story Resources
- Photo Essays: Starch, Seaweed and Shrimp Shells - Gifts to Agriculture, 25 September 2013
- Save Money, Water, the Environment - Benefits of Natural Polymers, 16 August 2013
- Marine Environments Under Growing Pressure, 17 September 2013
- Radioisotope Products and Radiation Technology Section
- The Blue Planet - Nuclear Applications for a Sustainable Marine Environment, IAEA Scientific Forum
There are millions of tonnes of trash floating in the ocean, consisting mainly of plastic bags, plastic bottles, food wrappers/containers, and other disposable plastic items brought there from poorly managed landfills, ships, polluted rivers and streams. Marine animals either get entangled in this debris or ingest it, which can result in birth defects and death.
Over time, floating trash also releases harmful chemicals and toxic metals into the marine environment, posing a risk to human health.
There are a few areas around the oceans where trash, namely plastic, brought by currents and winds, congregates. These so-called "trash islands" or "garbage patches", which are difficult to analyse or clean up because they move and change throughout the year, are a cause for serious concern.
While local, regional an international efforts are being made to clean them up, ways for efficient conversion of the debris to useful materials are also being explored.
The IAEA has focused its efforts on the plastic elements of these "trash islands". And the Agency believes that slowing (and hopefully) stopping the growth of these "islands" is a significant step in the global effort to solve this problem. So the IAEA supports its Member States - through technology transfer, training, and expert guidance - in the production of new environmentally friendly materials at competitive prices.
For example, the IAEA is working with Member States around the world to promote the adoption, manufacture and use of non-toxic, biodegradable natural polymers that are derived from plants and animals. Natural polymers are used to make a number of products, including plastic ones.
What's a Natural Polymer?
Natural polymers are large molecules made up of long chains of repeated blocks of atoms. They are found throughout nature: the cellulose in plants and trees; the starch in bread, corn and potatoes; in the shells of shrimps, crabs and other crustaceans; and in seaweeds.
These and other natural polymers are the perfect building blocks from which to develop new materials because they are abundant, inexpensive, biodegradable, locally available and renewable. They also have some remarkable inherent properties. Chitin, for example, is naturally waterproof, and hard, yet flexible.
Products made from natural polymers are used in medicine, agriculture, environment protection, cosmetics, and a variety of industrial applications.
For example, to promote plant growth and productivity, and increase their resistance to diseases, natural polymers are being used fertilizers and as "super water absorbents", which reduce how often crops need to be watered by storing excess moisture that plants can access in drier times. The environmental benefits of using these natural non-polluting products instead of chemical fertilizers on a large scale, is quite significant.
Natural polymers are used to make cooling, soothing hydrogel face masks and wound dressings, as well as being used in tissue engineering and for more efficient delivery of medicine into patients' bodies.
Natural polymers are also used in the food industry. They are being used to help make edible coatings for food products, which are used for preservation as well as protection from contamination.
How Radiation Processing Works
Radiation processing is used to break chemical bonds and create new ones, making it is possible to redesign a particular material, to customize it for a very specific purpose.
This process, during which natural polymer-based materials are exposed to ionizing radiation, can change the chemical, physical and biological properties of the material without the need for additional chemical processing, and without making the material itself radioactive.
Radiation processing has several advantages over conventional chemical methods for developing and manufacturing new materials and products. It's energy efficient and environmental-friendly because it changes the molecular structure of materials without requiring chemical catalysts or extreme physical conditions such as high temperatures and immense pressures; it neither uses toxic chemicals nor generates noxious fumes.
The IAEA, though its Radioisotope Products and Radiation Technology Section in the Department of Nuclear Sciences and Applications, has been promoting this technology for the last 40 years. Over the last 10 years, interest in the technology has grown faster in Asia and the Pacific than in any other region in the world, bringing with it the potential for significant benefits to industry, economic growth, health, agriculture and the environment.
Many countries are actively engaged in researching and developing new materials, patenting their discoveries, or bringing new products to market for sale domestically and internationally.
As more countries embrace sustainable and environmentally-responsible plastic manufacturing, it is the IAEA's hope that mounds of trash on land and in the seas will eventually become a thing of the past.
-- By Sasha Henriques, IAEA Division of Public Information
(Note to Media: We encourage you to republish these stories and kindly request attribution to the IAEA)