Plastic Bag Pollution The use of
plastic bags has increased at an alarming rate since they became popular in the
1980s. Big black bin liners, plastic carrier bags carrying advertising logos,
clear sandwich bags and a variety of other forms. They’re lightweight, handy and
easily discarded. Too easily discarded. Just take a look around you. Plastic
bags can be seen hanging from the branches, flying in the air, settled amongst
bushes and floating on rivers. They block up drains causing water and sewage to
overflow and become the breeding grounds of bacteria that cause
diseases. Plastic bags are difficult and costly to recycle and
most end up on landfill sites where they take around 300 years to decay. They
break down into tiny toxic (有毒的) particles that pollute the soil and waterways
and enter the food chain when animals accidentally consume them. But the
problems surrounding waste plastic bags start long before they decay. Our planet
is becoming increasingly endangered by our over-use of plastic
bags. Production of Plastic Bags Plastic
bags are made from ethylene (乙烯), a gas that is produced as a by-product of oil,
gas and coal production. Ethylene is made into polymers (聚合体) -- chains of
ethylene molecules -- called polyethylene. This substance, also known as
polythene, is used to produce a range of items, including plastic
bags. You have probably noticed two types of plastic shopping
bags -- the lighter, filmy bags you get from supermarkets and food outlets, and
the heavier bags from other retail outlets, like clothing stores. The
supermarket bags are made from high density polyethylene (HDPE), while the
thicker bags are made from low density polyethylene (LDPE). Unlike HDPE, LDPE
can not be recycled. While plastic bags may not be the most high
tech application of plastics technology, it is certainly one of the most
prevalent. According to Clean Up Australia, Australians use in excess of 6
billion plastic bags per year. If tied together these bags would form a chain
that is long enough to go around the world 37 times. More than half of these
bags (3.6 billion) are made from HDPE. Dangers to Sea
Life Plastic bags are now amongst the top 12 items of wastes
most often found along the coastlines. Animals and sea creatures are hurt and
killed every day by discarded plastic bags -- a dead turtle with a plastic bag
hanging from its mouth isn’t a pleasant sight but mistaking plastic bags for
food is commonplace amongst marine animals. Plastic blocks their intestines (肠道)
and leads to slow starvation. Others become entangled in plastic bags and
drown. Because plastic bags take hundreds of years to break
down, every year our seas become "home" to more and more bags that find their
way there through our sewers and waterways. Every bag that’s washed down a drain
during rainfall ends up in the sea; every bag that’s flushed down a toilet ends
up in the sea; every bag that’s blown into a river will most likely end up in
the sea. One disquieting fact stemming from this is that plastic bags can become
serial killers. Once an animal dies of plastic bags, it decays at a much faster
rate than the bag. Once the animal has decomposed, the bag is released back into
the environment more or less intact, ready to be eaten by another misguided
organism. The incredibly slow rate of decay of plastic bags also means that each
bag we use compounds the problem, because the bags simply
accumulate. Pollution Taxes & Bans
Different countries have adopted a range of approaches to discourage the
use of plastic bags in an attempt to cut down on the number of bags finding
their way into the environment. In South Africa for instance, where an estimated
eight billion plastic bags are used annually, the government has implemented new
regulations that will see only thicker, more durable plastic bags produced. As
well as making them more suitable for reuse, it is hoped that the extra cost
associated with their production and supply will prevent retailers giving the
higher quality bags away, making their use a more expensive option for
consumers. The use of plastic bags is being discouraged in other
places such as Singapore and Taiwan, while the tax imposed on the use of plastic
shopping bags in Ireland has resulted in the use of plastic shopping bags being
reduced by 900/0 in just six months. Prior to the 15 euro cent per bag tax, it
was estimated that 1.2 million plastic shopping bags were being handed out in
Ireland per year. The money raised from the tax will be used to fund
environmental initiatives. While anything that lowers our
consumption is good, why wait until we’re hit financially before we change our
habits when changes aren’t difficult to make How about taking
previously used bags with you next time you go to the shops Or even better --
turn back time and do as grandma did and take a bamboo basket with you every
time you go shopping. Shop-owners would rather you use their bags as they’re a
convenient and cheap form of advertising, but what’s more important, shareholder
profits or the environment Plastic bags can be re-cycled
although only about one in every 200 ever finds its way to a re- cycling unit.
Find out if there’s a re-cycling bin near you and, if not, ask your local
authority for one. Greenhouse Gases Some
countries have introduced so-called "environmentally friendly plastic bags" that
are biodegradable (可生物降解). These bags take about three years to break down into
practically nothing and while that sounds like an attractive solution, the truth
is that the process of breaking down these petrol-based bags causes carbon to
become methane (甲烷) which is a greenhouse gas. It’s also
possible to get "plastic" bags manufactured from corn. These break down very
quickly and give off no more methane than any other corn product on landfill
sites. Unfortunately, they’re more expensive to produce and few shops use
them. Garbage Bins One question that’s
often raised in connection with the plastic bag dilemma is what should be used
to line bins if not plastic bags To answer that, let’s go back
in time to when plastic bags were yet to become commonplace. What did we
doe. For one, we had far less garbage. Goods had much less
packaging than is the case today so we didn’t fill our bins as quickly.
Peelings, eggshells, tea bags and coffee grounds were all used as compost (肥料)
for crops, as was any paper that wasn’t needed for lighting fires. What was left
went into an unlined bin with anything dirty or wet being wrapped in newspaper
first. If we choose carefully when shopping so as not to bring
home more packaging than necessary -- there’s really no point in bringing it
home just to throw it straight in the bin when we unpack, the amount of waste
that goes into the kitchen bin will be halved, at least.
Individual Effort By refusing to use plastic bags, you
can make a huge difference to the pollution problem. Remember that each person
uses about 83 bags a year. If there are four people in your family, that’s 332
plastic bags less every year. That’s 332 bags less that will: --
release toxins into the ground water from landfill sites -- stay
in the environment for hundreds of years -- get into the food
chain through animals -- waste energy during the manufacturing
process -- kill any of the estimated 100,000 marine animals that
die each year of plastic pollution These are all-important
factors that have a profound effect on our environment and the creatures we
share our planet with. Should we really put our own selfish needs before the
needs of everything around us now and the lives of future generations That’s up
to you to decide. The passage mainly discusses the factors leading to plastic bag pollution..