science

Every once in a while the government here passes out an order banning shop keepers from providing plastic bags to customers for carrying their purchases, with little lasting effect. Plastic bags are very popular with both retailers as well as consumers because they are cheap, strong, lightweight, functional, as well as a hygienic means of carrying food as well as other goods. Even though they are one of the modern conveniences that we seem to be unable to do without, they are responsible for causing pollution, killing wildlife, and using up the precious resources of the earth.

Why Are Plastic Bags So Harmful to Our Environment?

The environment on earth is a highly sensitive eco-system, and so many man-made objects can throw it out of balance and cause long lasting harm and damage. One such man-made material is plastic, and so the question lies: why are plastic bags so harmful to our environment?

So, why are plastic bags so harmful to our environment then? To begin to understand, the materials used in plastic bags have to be looked at. Polyethylene is used for the majority of bags- whether shopping bags or bin liners, and is a non biodegradable substance, which contains some harmful chemicals when it does eventually rot down a little. Because of its use in packing items, 80 million metric tonnes of polyethylene are made every year, and this all has to end up going somewhere. The odd thing about people wondering: 'why are plastic bags so harmful to our environment?' is that they do not actually need to be all that harmful. Polyethylene can now be recycled, so it is important people do look out for local facilities in their area and don't just throw away their old bags.

The reason that so much damage is done to the environment when plastic bags are thrown away is mostly due to the fact it clogs up landfill sites, and takes centuries to rot down (although a recent finding means that in the future the government may be able to help them rot down quicker by using fungi). There is also, though, the fact that plastic bags are often discarded in a way that means they will end up in the world's seas. Plastic is a lightweight substance and the wind will often carry it out to sea where it can destroy marine habitats. Sea creatures may eat it and choke to death as it twists up in their digestive system, or it may suffocate or harm animals and emit toxins into the waters.

Choking is not only a hazard for marine sea life though, as plastic bags can affect any part of the environment. Anywhere there are animals; there is a risk of killing or harming them if a plastic bag is introduced into the landscape. This is why all plastic bags, if they cannot be reused, should be safely discarded and weighed down to prevent their movement from a landfill.

Plastic bags can also line forest floors, or wooded environments, if caught up on trees and rocks and prevent nutrients and new seeds reaching the soil, thus stopping the chance of any new plants growing on that bit of land. This is not a major problem yet, and can easily be reversed by moving them, but if more bags get clogged up in situations like this, it has the potential for long term damage.

Here are some of the harmful effects of plastic bags:

Superconductors

The resistance in many electrical machines such as electric motors, generators and transformers is large, producing vast amounts of heat during its operation. These machines have to be large in size to dissipate the heat loss.

There are some metals and compounds whose resistances fall to zero below a certain critical temperature, Tc. When their resistances become zero, these materials are called superconductors.