The pollution that is caused by organic polymer materials such as plastic on the environment thereby having harmful effect on human being is known as plastic pollution. Plastic mainly can be divided in two broader classifications namely.
- Thermosetting plastics
Both these varieties of plastics are not biodegradable that cannot be acted by micro organisms leading to the breakdown of the molecules. Generally most of the organic materials such as proteins in human and animal systems, paper, wood, vegetable materials etc. are prone to bacterial action and get putrified leading to mineralization. But it is not possible for any plastic waste material to undergo degradation leading to mineralization. The plastic packing and other waste material will be present in the environment for indefinite time. Hence the disposal of plastic waste material has created a very great challenge to the present generation.
The main sources of plastic pollutants are the polythene bags. Besides this the broken home appliances made of plastics, broken plastic chairs and furnitures mainly contribute to the waste materials. The industries producing plastic materials also release plastic waste materials into the land and water sources.
There are several drawbacks of using polythene:
- It creates unaesthetic appearance in public places, residential colonies, tourist spots, and others.
- Because of its lightweight, they are very easily lifted by winds and may reach open drains, which further cause blocking of sewer lines, and floods during monsoon
- If dumped in landfills, they stay for a long time causing impaired biochemical reaction.
- The colouring pigment in coloured polythene bags leach out to oil in dumpsites causing ground water contamination.
- The intake of polythene bag by stray goats, cows etc causes choking in the throat and stomach which leads to death and
- Accumulation of polythene bags near the seashore is very common in India.
Many states in India such of Haryana, Himachal Pradesh, Tamil Nadu and others have banned the use of polythene. The Udagamandalam or Ooty of Tamil Nadu a hilly area was declared as plastic free zone. Although efforts are applied to produce biodegradable plastic or polythene’s by using corn-starch, till now it is not commercially successful. Hence, there is no other option than to use them carefully keeping in mind the three important abbreviations for R- Reduce, Reuse and Recycle. Apart from plastics and polythene’s, there are different materials like paper, metal can, tin products etc which are being used as packaging materials.
- It has been suspected that some of the polymer chemicals are carcinogenic.
- Plastic polymer molecules can get into the system through the food chain or directly and can cause sterility.
- Fishes are the main scavengers of plastic trashes and the polymer chemicals get absorbed into the body of fish. When human beings eat such polluted fishes, they can develop deformities, defects in uterus etc.
- Polythene and other vinyl polymer plastics present in the land can stagnate the water and produce breeding grounds for mosquitoes.
- Besides affecting fishes, many marine animals such as sea lion, seal, sea turtle, sea bird etc. are greatly affected by the plastic pollution of the sea. Some of the specific polymer molecules such as poly chlorinate biphenyls (PCBs) cause severe damage to human s well as animal reproductive system. Many of the industrial effluents as well as waste plastic articles are dumped into the sea that causes marine plastic pollution.
- The domestic animals consumes plastic trashes without knowing its contents and become victims to the plastic pollution.
- Nowadays the domestic sewages are greatly polluted by plastic waste materials as well as synthetic detergents. This hinders the proper microbial treatment for the domestic wastes.
- The best way to dispose the plastic materials is to sort them out separately and send them to the recycling plants where they can be converted into articles of use. But it is always better not to use plastics for carrying or packing food articles especially in the hot state.
- The behaviour and etiquette of the people should be changed through proper education so that people should throw the plastic bags or packing materials in the dust bins.
- In the case packing of cooked food or hot drinks it is always better to use cellulose plates or containers or packing materials.
- The research and development in the field of bio-degradable polymers has achieved great discoveries in medical field but it has to cross the barrier in the domestic front where plastic containers and bags has to become biodegradable.
Many kinds of copolymers involving monomers such as starch, cellulose etc with other strong polymers has been tried but till now it has not produced fruitful results.