Return
to Story Page
To print: Select File and then Print from your
browser's menu
Sudhir Ghatnekar/Mandar Ghatnekar
The past hundred and fifty years of this millennium have witnessed an unbelievable pace of scientific and technological development making this century seem like a sci-fi novel. Modern science has attempted, and to a great extent succeeded in realising the dreams and fantasies of philosophers and scientists of the previous centuries.
Industrial processes developed in the early part of this century relied greatly on natural resources and the products of these industries were largely biodegradable. However, with an increase in demand for industrial goods, these manufacturing industries could no longer depend only on natural raw material.
Thus research was diverted to the development of artificial or synthetic raw material. This marked the boom in the chemical industry. A slight problem, which the scientific community overlooked, was that the products of these industrial units were also `artificial' or synthetic in nature, with the result that they could not be degraded in the natural environment.
Publicawareness for the need to avoid endangerment of the natural systems that support life on earth, i.e. the atmosphere, water, soil and living beings has also intensified. Thus the need of the hour is sustainable development in the manufacturing processes. Considering the limitations of renewable resources, there is a need to improve the efficiency of industrial processes thus minimising wastage. Another approach for the development of sustainable technology is to design Eco-friendly products, which can be derived from the vast diversify of life forms on the earth, thus making them biodegradable.
Plastic is considered to be an invaluable gift of modern science and technology to mankind. This unique wonder material has some mutually exclusive qualities of being very light, yet strong and economical. Yet how much ever we may applaud the qualities of plastic and their importance in day0to0day life, the fact remains that this same material is now proving to be a curse to the environmental scientist.
The mammothscale of use of plastics and their improper disposal has threatened natural environment the world over. Thus the need of the hour is to find alternative materials, having the physical and industrial properties similar to petrochemically derived plastics, which are biodegradable.
Harmful effects of conventional plastics:
Over the last few years, an increasing number of reports have appeared about reproductive problems in both wildlife and humans. Reports of alligators with malformed reproductive organs, feminization of fish in UK rivers and changes in the mating behaviour of gulls have appeared. Apart studies also showed a decline in human sperm count and sperm quality, an increase in testicular cancer and genital abnormalities, such as undescended testicles, and a rise in the incidence of breast cancer in women. Indeed that was a price we all paid in the past, are paying currently and perhaps likely to continue paying in the future too.
Many chemicals are also passed through the mothers breast milk tothe nursing infant. It has been estimated that an infant who is breast-fed for one year will receive between 4 and 12% of its lifetime exposure to dioxin.The rise in the levels of toxic chemicals sin the environment can be directly linked to the rapid increase in synthetic chemical manufacturing units. Dioxin the major pollutant are known to be the by-products of such wide-ranging processing activities as :
The conclusions of many of these studies is that man made chemicals in the environment are suspected to be interfering with hormonalsystems in both humans and wildlife. Thus the need of the hour is the development of sustainable technologies based on the principle of environmental protection. Plastic industry which is one of the main contributor of harmful chemicals in the environment needs to be seriously revamped.
Viable alternatives will have to be explored to phase out the use of PVS like plastics in our day-to-day life as well as in certain industrial applications. Several new Eco-friendly materials have the potential to replace conventional plastics. They are:
The search for such biodegradable plastics has led to a number of partially andcompletely biodegradable plastics. Partially biodegradable plastics are essentially blends of conventional plastics with biodegradable biopolymers like starch, cellulose, and derivatives of these carbohydrates, etc.On the other hand completely biodegradable plastics like polylactides, polyhydroxyalkanoates, aliphatic polyesters, polymers of cellulose acetate, etc., are being developed. However, the major hurdle in the use of these biodegradable plastics on a commercial scale is their prohibitive cost.Biodegradable plastic materials (BDP) can be produced from renewable and from fossil non-renewable resources, Usually they are thermoplastic and therefore processable by plastic processing method.
Older BDPs have been permitted as food packaging in Germany several years ago. Cellulose hydrate is used with sweets and as artificial skin for sausages. Cellulose acetate has been used for dry food without fat. At the Olympic Winter Games in Lilehammer, biodegradable products were used for catering. Investigationsfor yogurt cups are ongoing, Foil bags for the collection of biological waste and biodegradable loose - fill packaging materials are already in use.
Ecological :Aspects
A new alternative for waste management has been created by the invention of BDPs. This does not necessarily mean general ecological superiority to conventional packaging materials.
Superiority could only be proved by means of life cycle assessment. Life cycle assessments are hardly available even for the various conventional packaging. Studies comparing conventional and biodegradable packing are not known. But a life cycle assessment on materials basis has been published recently. It certainly reveals advantages for BDPs, especially considering the protection of the atmosphere.
However, the production conditions for BDPs are subject to severe improvements at present. Most production plants are still in the scale-up phase. This makes it difficult to gain reliable data for a life cycle assessment.
Let us hope that by beginning of thenext Century we shall replace at least 25% of conventional plastics to new environment-friendly biodegradable plastics.
The authors are scientists with Biotechnology Resource Centre, a private research body in Mumbai
Copyright © 1999 Indian Express Newspapers (Bombay) Ltd.
------------------------------------------------------------
This story was printed from Net Express located at http://www.expressindia.com. Net Express provides a portal to India, with news from The Indian Express and The Financial Express along with sites on travel and tourism, the entertainment industry, the power sector, the environment and much more.
------------------------------------------------------------