Plastics are everywhere around us – in our homes, our vehicles, our computers, as packaging – replacing more traditional materials such as wood, metal, glass, leather, paper and rubber because they are lighter, stronger, more durable and corrosion resistant, and often cheaper.
But that durability means that most plastics do not biodegrade, so almost all the plastic ever produced is still here somewhere on the planet in one form or another, and will remain here for centuries to come, possibly up to 1000 years – nobody knows for certain yet.
Total global production of plastics was just 5 million tonnes per year in 1950, but had risen to 245 million tonnes by 2006. In the UK we now use about 5 million tonnes a year, over one third of this for packaging. Only a small proportion is reclaimed or recycled, and an extraordinary amount of plastic waste now occupies landfill space worldwide.
In addition it’s estimated that 5% of all the plastic produced since the 1950’s is now in the world’s oceans, comprising 90% of all floating marine litter – the United Nations Environment Program estimated in 2006 that on average every square mile of ocean contains 46,000 pieces of floating plastic.
About 20% of this comes directly from shipping, mostly from containers lost overboard. Some is intentionally fly-tipped. The rest comes from the land, swept by tides, wind, rain and floods into streams and rivers and out to sea. 70% eventually sinks to the ocean floor. The rest floats, much of it ending up in oceanic gyres as massive islands of waste such as ‘the Great Pacific Garbage Patch’. It may eventually be deposited as litter on a beach, or could float around for decades before breaking down into smaller particles and becoming absorbed into the food chain or sinking and becoming part of the ocean floor sediment.
Quite rightly, much attention has been focused on the dangers of plastic litter to seabirds, whales, dolphins, turtles, seals and other marine life. It’s thought to cause the deaths of over a million seabirds and more than 100,000 marine mammals each year, but researchers are now warning that the risk of hidden contamination could be even more serious.
Unlike biological materials, plastic doesn’t decompose. Instead, it photodegrades when exposed to sunlight, fragmenting into smaller and smaller pieces without chemically breaking down. In large areas of ocean tiny plastic bits, often called ‘mermaid tears’, have been found to outweigh the plankton by a factor of six to one or more.
But, no matter how small they become, these plastic bits never become digestible by any living creature. In addition they contain additives such as pigments and plasticizers, known to be endocrine disruptors, plus toxic metals such as cadmium and lead. Recent research by the University of Plymouth has shown that the particles also attract toxic chemicals from the surrounding seawater and concentrate them on the surface of the plastic, acting as ‘magnets’ for poisons in the oceans.
These small poisonous particles, found throughout the oceans and mixed with the sand on beaches, are now threatening the entire food chain. The toxins they contain are known to be a threat to human health. In the water the particles are mixed in with and resemble the plankton, and are being eaten by filter feeders, which are then consumed by large creatures. The process of bio-accumulation has the potential to further increase the concentrations of toxins as they pass along the food chain and into our human diets.
More information:
- BBC News Report ‘Warning on plastic’s toxic threat’
- Plastic in the environment
- The ‘great pacific garbage patch’ (video)
- Synthetic sea – plastic in the open ocean (video)
- Message in the waves – endocrine disruptors (video)
- Waste Watch information sheet on Plastics
- Greenpeace report on hormone disruption and PVC plastic
- Modbury, Devon – plastic facts page
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Posted under cause for concern, educational resources, plastic, waste
