Financial Daily from THE HINDU group of publications
Tuesday, Feb 10, 2004
Paper, Board & Newsprint
Industry & Economy - Environment
Let paper and plastics coexist
T. S. Viswanathan
Bags and other plastic materials are not biodegradable and, therefore, remain in the soil for long, discharging toxic chemicals that not only damage the soil structure but are also carcinogenic. They also clog drains and block free-flowing waterways.
Plastics such as polyvinyl chloride emit toxic chemicals carbon monoxide, dioxins and heavy metals when burnt. And the unnerving fact is that many of the compounds used for plastic production can cause health problems such as cancer, infertility and other reproductive abnormalities.
The softeners and additives used in the manufacture of PET (polyethylene terephtalate) bottles, generally used for storing drinking water, are carcinogenic and can enter the body easily, as they break down into molecules that mix well with water. Polyvinyl chloride, polystyrene, polycarbonate, polyurethane, and so on, are some of the other dangerous plastic by-products. Polystyrene foam can even cause ozone layer depletion.
The claim that plastics can be recycled is not entirely true, as two or more varieties are often fused together, and there is no market for such composites. And given that rag pickers are paid a measly Rs 1.50-2 per kg of such plastic waste gathered, there is no motivation for them to collect more.
Notwithstanding these disadvantages, whether replacing plastics, especially as a packaging medium, is justified needs to be analysed.
Plastic is a by-product of crude refining. The benefit of using some extra energy to convert a portion of crude into plastic cannot be denied. World over, only 4 per cent of the drilled oil is converted into plastic.
The general impression that paper when used as a landfill is biodegradable may not be entirely correct. In dry areas, biodegradation happens very slowly. And most of the decomposition underground takes place in the absence of oxygen, resulting in the release of toxic gases such as carbon dioxide and methane the main sources of global warming.
Globally, while plastics as a landfill account for 7 per cent by weight and 18 per cent by volume on an average, the figure for paper is 40 per cent with respect to both the measures.
Following the Bhopal gas tragedy, methyl isocyanate, the toxic intermediate used in manufacture of plastics, has now been replaced worldwide by more environment-friendly inputs. Thanks to technological advances, only miniscule amounts of toxic substances are generated in plastic manufacture. Therefore, this may not have much environmental impact.
In 1988, an experiment banning the use of polystyrene foam packing (PSF), especially for food products, by Portland, US, was found to have a number of unfavourable effects. For instance, the alternative methods of packing paperboard, glass or aluminium were very expensive and impractical. And in volume terms as the landfill of PSF was minuscule, Portland lifted the ban.
Paper recycling is not environment friendly either. The paper carton carrying milk, for instance, has a coating of polythene to retain the water content in the milk.
Paper, being permeable, cannot hold water for long. Also, paper recycling involves considerable usage of water, chemicals, energy and a mixture of pulp.
According to Prof Richard S. Stein of the University of Massachusetts, the incineration of plastics need not lead to generation of toxic fumes.
In an article `Plastics can be good for environment', he explains how plastic trash can be converted into energy using good incinerators without any toxic emissions.
Experts acknowledge that the wet strength of plastics is much higher than that of paper. For instance, a kg of plastic bags can carry what 20,000 kg or 20 tonnes of Kraft paper can.
To produce one tonne of paper, an integrated mill would require 1.5-2-lakh litres of water and huge amounts of power, coal and fibre. Even to make a tonne of waste-paper, approximately 20,000 litres of water is needed. Toxic chemicals such as dioxins are released during pulp and paper manufacture. Though effluent control methods are in vogue, studies question the effectiveness of these in preventing toxic substances from flowing into water systems.
Also, there is the rather painful fallout of destruction of forests. To prevent deforestation, there are suggestions to replace writing and printing paper with plastics by using sophisticated inks.
The other substitutes for plastics, such as glass, steel and aluminium, have their own disadvantages depletion of natural resources being one.
Thus, the logic behind banning plastics is weak. If PET bottles are banned because they contain polyethylene terephtalate, what about substitutes such as paper or glass, which also give out equal toxic substances during manufacture?
Environmental effects apart, what about the cost, mobility and convenience factors?
The main problem with plastics is disposability. But this can be solved to a large extent if households have two waste bins, one for plastic and the other for non-plastic items, and dispose the same in separate disposal bins that municipal corporations should provide.
The municipal corporations can then dispose non-recyclable plastic using sophisticated incinerators to completely prevent any toxic emissions.
Thus, there is no gainsaying the usefulness of each of the materials plastic, paper, glass and steel. No product can completely substitute the other. It can only be complementary. Environmentalists should weigh the pros and cons of each before going public with their opinions.
(The author is a paper trader and paper products manufacturer and a former faculty member of LIBA, Chennai.)
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