Various types of plastic materials are in use these days mainly because such materials are relatively inexpensive, sturdy and do not rust or rot besides being light in weight and non-conducting.
But this can also be a great problem. These materials are non-biodegradable and most Eco-unfriendly. Hence they keep accumulating in the environment. Plastic bags, cups, wrappers, other packaging materials, broken parts of plastic objects etc are seen littering the countryside, beaches, vacant lands, drains, hill slopes and numerous other sites all over the world. In fact these are ubiquitous. Numerous animal deaths due to consumption of plastic materials inadvertently, choking of drains & sewers, unsightly appearance are but some of the hazards associated with improper disposal of plastic wastes. This is in addition to the extremely toxic effluents of industries engaged in the manufacture of plastics. These effluents pollute the soil as well as air & water.
Various methods disposal have been tried and recommended to suit various requirements. These include the following:
Intense public awareness is the key to any successful effort to reduce hazards associated with the menace of plastic wastes.
However newer technology is also being developed in this regard. This entails the use of DEGRADABLE PLASTICS. The principal is to incorporate into the plastic some chemical that is photodegradable/biodegradable or chemically treatable.
Biodegradable plastics are generally made by adding starch. On burial such plastics are attacked by bacteria feeding on starch, which breaks these down into tiny particles that disappear harmlessly into the soil. Some common examples of biodegradable plastics are the use of non-removable suture materials in surgery or capsules for drugs, which dissolve slowly in body fluids.
Chemically degradable plastics can be broken up by spraying them with a solution that causes them to dissolve. For example such material can be used as a protective waxy covering for new cars, that washes off at the dealer’s garage by a specially formulated spray. This spray reacts with one of the components of the plastic and causes it to dissolve into harmless materials which can be flushed down the drain.
Photo-degradable plastics contain chemicals that slowly disintegrate when exposed to light. In France, strips of photo-degradable plastic about 3 ft (1mtr) wide are used to retain heat in the soil and produce early crops. They last for about 1 to 3 years before rotting into the soil. But they have to be used in places with consistent amount of sunshine so that they decay at a predictable rate. In the USA, about one quarter of the plastic yokes that link beer cans in a six pack are made of plastic called Ecolyte, which is photo-degradable. But to stop them decaying too early, they must be stored away from direct sunlight, which can be of some inconvenience to the retailer.
However degradable plastic can have a few other problems. For example, it cannot be recycled because there is no easy way to measure it’s remaining life span. The biggest drawback is the cost of it’s production. Japanese scientists however claim that they will soon be able to produce much cheaper multipurpose biodegradable plastic. In order to obviate the disposal problems and to prevent environmental pollution caused by routinely used polythene packaging materials, it would be prudent , for the present, to use eco-friendly paper packaging. The manufacturers of plastic packaging like soft drink bottles/mineral water bottles etc must come forward and develop appropriate methods of disposal/ own responsibility for disposal.
Dr G P I Singh, MD, DIH
Professor of Preventive & Social Medicine
Dayanand Medial College & Hospital
Ludhiana – 141001