First we need to understand what is plastic These are polymers. Polymer is defined as something which is made of many units. It is like a chain. Each link of the chain is "-mer" that is usually made of carbon, hydrogen, oxygen, and/ or silicon. Many links are hooked or polymerized together to complete the chain.

Natural polymers include such things as tar and shellac, tortoise shell and horns, as well as tree saps that produce amber and latex. These are processed with heat and pressure into useful articles like hair ornaments and jewelry. Natural polymers began to be chemically modified during the 1800s. The most famous of these were vulcanized rubber, gun cotton and celluloid. The first synthetic polymer produced was Bakelite in 1909 and was soon followed by the first synthetic fiber, rayon, which was developed in 1911.

Then consumerism caught up everywhere and plastic was started to be produced in different forms to be used in various ways. Toys, bags, etc all started to be made of plastic then. Of all such bags what is of most importance to people are grocery bags.

After the Plastic grocery bags came into existence, it has caught up like wild fire with every shopkeeper. Being cheap and easy to produce, reliable and convenient to carry, it has become very popular in the market.

A trade group within the Society of the Plastics Industry based in Washington, D.C. - Film and Bag Federation, said that the right choice between paper and plastic bags is clearly plastic.

In comparison to paper grocery bags, Plastic grocery bags consume 40% less energy, generate 80% less solid waste, produces 70% fewer atmospheric emissions, and releases up to 94% fewer waterborne wastes, according to the federation.

The economic advantage of Plastic grocery bags over paper bags are too significant for store owners to

ignore. It costs one fourth of a paper bag.

First introduced in the 1970s, plastic bags now account for four out of every five bags handed out at the grocery store.

But with all the advantages comes the disadvantage too, the immense success of the bag has meant a dramatic increase in the amount of floating plastics in the oceans, rivers, streams and drains where they choke, strangle, and starve wildlife and raft alien species around the world.

Discarded plastics pose a threat to human health and environment. Due to its non-biodegradable nature, littering of plastics causes irreversible damage to the environment. Plastic wastes hinder the natural aeration process of the surface water bodies, choke municipal sewer lines and storm water drains and clog the bar-screens of sewage treatment plants. They interfere with various agricultural operations, prevent natural recharge of underground water and contribute to visual pollution. Consuming food wrapped in coloured plastic has adverse effects on health. Municipalities routinely receive reports of death of cows and other animals from ingesting plastic waste, especially plastic bags. Municipal authorities have two options for plastic disposal: incineration and landfill. While plastics remain fairly inert in the landfills, the large volume to mass ratio of plastics aggravates the scarcity of landfill space.

Due to environmental reasons countries like Ireland, Taiwan, South Africa, Australia, and Bangladesh have heavily taxed or banned their use. Several other regions, including England and some US cities, are considering similar actions.

But as I said earlier advantage and disadvantage go hand in hand, so plastic bags have certain uses too. Food can be freezed in it in an inexpensive way. It can be used to line trash cans and can be used as disposable gloves for tasks that dont need finger to be used. It can be used as rain proof packing and to pack soiled clothes while traveling without the fear of the other clothes catching the smell.

Students and office goers prefer to pack lunches in plastic bags saving the effort of carrying and washing lunch boxes. Housemaids use these bags to throw wastes in the dust bin. The milk and bread men pack their goods in plastic bags before delivering them. Deep freezers are stocked with food stored in plastic bags.

According to researchers plastic degenerates slowly, their degeneration time could be anytime from twenty to a thousand years and as time passes the plastic lies somewhere in between complete preservation of structure and complete loss of structure. In other words all plastics sooner or later break down into small pieces, leaving behind plastic-chunks or plastic-dust as residue. These chunks and dust are not biodegradable as their molecular structure is too large for micro-organism to swallow. This characteristic of plastic causes serious environmental and health problems.