Saturday, February 20, 2010

Plastic pollution - perils of plastics

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’

The word plastic is derived from the words plasticus (Latin for “capable of moulding”) and plastikos (Greek for “fit for moulding”).Plastic is basically a formless material which can be moulded under heat and pressure. All plastics are made from three raw materials: Petroleum, Coal and Cellulose.

Kinds of plastics

There are two main groups of Plastics:Thermoplastics and Thermosets
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

Polyethylene (PE),Poly vinyl fluoride (PVF),Polypropylene (PP),Bakelite
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.

Advantages

Plastics 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.

Disadvantages

Plastics 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

Plastic pollution on land causes both physical and chemical changes. Plastic reduces soil fertility by forming the part of manure for years. Plastic spoils environmental aesthetics and hygiene. Plastics constitute approximately 11.8% of the weight of municipal solid waste (MSW). Plastics cause serious aesthetic problems in the land fills and emit hazardous VOCs during incineration. Naturally the bacteria in the soil require 500-1000 years to decompose plastics. Plastics take around 300 years to photo-degrade. Plastic on soil can lessen the growth of plants and trees by blocking the absorption of minerals, water and other nutrients. Plastics on soil can also make land slides.

Effect on Air

Several 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 environment

Plastic 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 environment

Effects 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

Toxic chemicals contained in plastics cause cancer, birth defects, hormonal changes, gastric ulcer, thyroid problems and cardiovascular diseases. The endocrine disrupting chemicals (EDCs) in plastics have been contributing to obesity and diabetes. The plastic bottles may leach cancer-causing and hormone - disrupting chemicals such as phthalates ( a component makes plastic pliable) and Bisphenol A ( a component harden plastics). Bisphenol A( BPA) a synthetic estrogen can affect the hearts of women and can permanently damage the DNA of mice.

Prevention of Plastic Pollution

REFUSE 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.

3 comments:

  1. I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


    Susan


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  2. I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


    Susan


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