Dr. Banarsi Lal
Many drastic changes have occurred in the human life during the last half century and one of the most instantly observable is the abundance of plastic based products. Plastics continue to help society in innumerable ways but recently they are observed as environmental threats. Plastics are derived through reinforcing fillers, antioxidants with synthetic polymers and colourants. Plastics manufacturing require less energy as compared to metals and glass. Plastics meet large share of the modern society due to their low cost, light weight, high strength, environment stability, ease to carry etc. Plastics have imprints on environment and human health due to their hydrophobic and inert nature. Plastics disadvantages prevent them from becoming universal building block of human civilization. Governments strictly control their use and impose laws governing their manufacture, disposal and recycling. Social need of plastics is well recognized and it is extremely difficult to select the alternatives of plastics.
Plastic is a necessary evil. It is estimated that every year the amount of disposed plastics can four times circle the earth. We can’t live without plastics as every day we come across plastic in various forms such as bottles, grocery bags, food containers, computer keyboards, plastic mouse, coffee cup lids etc. It is startling to note that billions of tons of plastics are ending up in the oceans. Plastics take thousands of years to decay. Plastic is an incredibly useful material but it is made up of toxic compounds known to cause illness as it is non-biodegradable. Plastics negatively impact the natural environment and create problems for plants, wildlife and human beings.
Plastics received social acceptance in 1600 BC. Ancient Mesoamericans firstly processed natural rubber into rubber bands, boots, coverings etc. Until 19th century man was relying on plastics, rubber and resins. The first plastic was developed by Belgium born American chemist Leo H. Baekeland called Bakelite. Alexander Parkes, a metallurgist from Birmingham developed man made plastic. Throughout his life he made lot of discoveries and secured 66 patents. In 1950 he produced flexible transparent material called as Parestine by blending Camphor and Nitrocellulose. Presently versality of plastics have led to a great increase in their use. Environmentalists have denounced man made plastic as a long lasting pollutant which does not fully break down. It is very difficult to measure the pollution caused by the plastics. There are more than 20 different types of plastics which cause pollution. Many parts of the world excessively use the plastics. The per capita consumption of plastics in India is 4%. It has been observed that the disposed plastics based consumer products and infrastructures are the major source of pollution from their manufacture. Plastic waste in big Indian cities averages just50-100gm/capita/day as compared to 1-2Kg in the Western world. In Delhi the highest plastic waste is piles as 690 tons/day. Generally, plastics are thrown away after the use but because they are durable, they persist in the environment. Improper disposal of plastic generates litter that drains into the rivers, streams and ultimately pollute the environment. Plastics laced with the chemicals are ingested by the animals that leads to infection and death. Polyolefin constitute the group of non-degradable plastics comprising low density polyethylene, high density polyethylene and polypropylene. They are used for the manufacturing of containers, bags and laminates. Their decomposition evolves carbon monoxide, furans, carbons and dioxins that cause the breathing problems. In order to incorporate certain characteristics several chemicals are added in the plastics. These are Bisphenol A, Phthalates, flame retardants etc. Styrene migrates significantly from polystyrene containers into containers contents when oily foods are heated in such containers. Styrofoam from tea cups, food containers and cutlery leaches styrene, an endocrine disrupter mimicking the female hormone estrogen and causes cancer, reproductive disorders, asthma and multiple organ damages. Their long time use causes ill effects on the nervous system and red blood cells. Antimony trioxide and Phthalate from Polyethylene terephthalate and Polyvinyl chloride effects the female hormone estrogen and allergies in the children. Cadmium leached from the plastic bags accuses vomiting and heart enlargement. Lead exposure for long time causes degeneration of brain tissues. Disposal of plastics through land filing evolves noxious additives, colorants and antioxidants are leached off from buried plastic waste that spread into groundwater and impose potential human health hazards. Contamination of plastics in the soil effects agricultural production. Thermal degradation of plastics releases noxious monomers, additives, halogenated hydrocarbons and oxides that adversely affects the human health. The global plastic production and consumption have increased from the last five decades but their actual role as pollutants is uncertain. It is not certain that what level of exposure is caused by plastic waste and mechanism of their effect on human health is still not clear. Recycling of waste plastics can be done to reduce the hazardous impact on the environment. Recycling of the plastics helps to reduce carbon dioxide emissions. Plastics picking and their recycling is an old business in India. Now this is a well-established urban-survival tactic in mega-cities that supports up to 0.5% of the poor population in many cities and saves the 10-15 per cent of the total waste management costs through the volume of plastic waste.
