Mike the Psych's Blog

What if psychologists ruled the world? In real life?

Hot air about plastic bags

Are you for or against re-cycling? Do you still use plastic bags or have you converted to re-useable ones?

Some people are almost eco-fascists while many others are sceptical about separating rubbish convinced it all goes to landfill anyway.

And I have some sympathy – if I don’t want smelly containers in my bin all week I have to wash them (Germans are apparently very good at that) and I use energy for that don’t I? But now it seems that plastic bags may not be quite as bad as environmentalists think. At least compared to the alternatives.

We are using almost 50% fewer bags than in 2006 and they make up less than half a percent of all the litter according to Keep Britain Tidy (food being the most dumped item in landfill). And paper bags, material bags, and degradable ones, all release methane which is worse for the climate than CO2. Some reusable bags are difficult if not impossible to dispose of and they need to be used at least four times before they have less impact on the environment than ordinary bags.

Tesco has reduced bag use by 55% and expects it to be 70% by 2011. Marks & Spencer has done the best with an 83% reduction but has been criticised for charging 5p a bag.  But that’s how Ireland reduced bag use although they found that they had to increase the price when  bag use starting rising again.

But if you think we worry too much about plastic bags there is a the “Great Pacific garbage patch” to consider. This is basically an area possibly twice the size of the USA which stretches from America across Hawaii to Japan, in two large patches. It has been called the “trash vortex” and is like plastic soup with very small invisible particles in addition to the obvious lumps of plastic shards and nets, all trapped by ocean currents, like a modern Sargasso Sea.

These particles are ingested by sea birds, fish and marine wild-life generally. They disrupt hormone systems as well as the larger chunks being indigestible. It may take 6 years for the plastic waste to travel from mainland America to the vortex but it might eventually end up back on your dinner plate. How tasty is that?

Updated 10 August 2010: San Francisco banned plastic bags in supermarkets 3 years ago is proposing to outlaw them from next March at all retailers, including small businesses and corner shops, making it the first US city to impose a complete ban.

As a result of the earlier ban it’s estimated that 100 million fewer bags have been used each year reducing landfill and street litter as well as the risk to wildlife. There are still a lot around though and volunteers picked up over 70,000 plastic bags on the coastline in one day last year.

Opponents from the Progressive Bag Affiliates, which represents many plastic bag manufacturers, point out that 65% of Americans re-use their plastic bags and that plastic bags use 70% less energy to make than paper bags and produce half the greenhouse emissions in the process. And it takes 7 times the number of trucks to deliver paper rather than plastic bags.

Meanwhile back in Britain, according to the Times report yesterday, shops handed out 10 billion plastic bags last year.

Updated 2 May 2011: Plastic fibres have been found in over 80% of the scampi caught the Clyde estuary. The fibres were found in tangled balls in the stomachs of the crustaceans which are unable to excrete them. Concern has been raised about whether harmful chemicals from the plastic could leach into the edible flesh and harm humans.

The plastic comes from a variety of sources including polythene bags and plastic discarded from yachts (ships discard about 6.5 million tons of plastic every year). The main source however is probably from the nets used by the trawlers which are non-biodegradable synthetics such as nylon, polypropolene and polyester.

As we usually only eat the tail end of these animals rather than the gut the danger of poisoning is probably quite low although the potentially carcinogenic chemicals from the plastic could find their way into the edible flesh and and into soups (made from the heads and guts). Plastic debris in the oceans has been shown to absorb restricted or banned chemicals like DDT

According to the article in the Times, a 2007 study found that 86% of turtle species, 44% of seabird species, and 43% of mammal species were affected by plastic debris.


Author: mikethepsych

He says he's a psychologist but aren't we all?

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