Plastic is one of the non-biodegradable toxic pollutants which pollutes land, air and water. Plastics are organic polymers (synthetic or natural) of high molecular weight. Plastic causes serious damage to the environment both during its manufacture and disposal. People use plastic in a variety of ways ranging from household appliances to industrial and commercial products. Plastics are made from petrochemicals, a non-renewable resource. Approximately 8% of world oil production is used to make plastics. The production of plastics is growing about 9% annually. According to an estimate, about 100 million tones of plastics is produced every year all over the world.
The name ‘Plastic’
Kinds of plastics
Thermoplastics become softens on heating and harden again when they cool. eg. polyethylene.
Thermosets become harden , when they are heated and cannot be softened by further heat e.g Bakelite
More than 50 families of plastics have been produced
Polyurethane,Nylon, Polyvinyl chloride (PVC),Terylene, Polystyrene (PS)
Cellulose acetate and Polycarbonates
Properties of plastics
Plastics are light weight, flexible, strong and durable. Plastics can be clear or opaque and easily molded into wide variety of shapes, sizes and colors. Plastics are chemical /corrosion / moisture resistant. Plastics are relatively cheap compared to metals. Plastics are reusable and recyclable.
AdvantagesPlastics are good electrical / heat insulators.
They do not corrode or decay.
They are relatively cheap to produce in large quantities.
They have good resistance to chemicals , water or grease.
DisadvantagesPlastics can either be non-biodegradable or degrade very slowly causing serious threat to natural environment.
Plastics can contaminate foods with dangerous chemical compounds.
Plastics are flammable and release toxic fumes when burned.
Plastics usually have low melting points and therefore they expand with heat and eventually melt.
Plastics have low tensile strength and so they are not as strong as metals.
Environmental effects of Plastic pollution
Effect on land
Effect on AirSeveral chemicals used in the manufacture of plastics are highly toxic and pose serious threat to all living species. (benzene, vinyl chloride, ethylene oxides, xyloms and Bisphenol A). During manufacture, plastic industries release greater amounts of carbon monoxide, dioxin and hydrogen cyanide. These gaseous pollutants contaminate air and cause respiratory diseases, nervous systems disorders and reduction of immunity to diseases in the human population. Burning of plastics release hazardous volatile organic compounds (VOCs) into the air.
Effect on freshwater environmentPlastic wastes dumped into water resources contaminate and poisons freshwater life. On leaching in water, plastic can easily enter the food chain and harm human health. Plastic debris clog the sewage drains. Chocked drains cause flooding during the monsoons.
Effect on marine environmentEffects of plastics on marine life include the entanglement and ingestion of debris by marine vertebrates and food-chain bioaccumulation of toxic additives by other species. Turtles become entangled in discarded nets and turtles were found dead with plastic garbage bags in the stomach. About 44% of sea birds eat plastic mistaken for food. Plastic is mistakenly eaten up by birds, turtles, seals and whales. This may choke them, poison them or impede digestion or cause starvation.
Effect on Human Health
Prevention of Plastic PollutionREFUSE Single-use-plastics (SUPs) – Refuse plastic carry bags at the grocer’s shop. use natural fibre bags.
REDUCE Waste – choose products with minimum plastic packaging.
REUSE – Preferably reuse non-toxic containers and goods.
RECYCLE – Recycling is not a sustainable solution. Recycling can be a last option.