Plastic Is More Biodegradable Than We Thought. (That's Bad.)

By Allison Bond | August 21, 2009 4:05 pm

plastic beachHere’s the good news: Plastic may break down in the ocean in as little as a year, not 500 to 1,000 years as scientists previously thought. Now, the bad news: This degradation could be releasing harmful compounds such as bisphenol A (BPA) into the ocean, according to research presented at the American Chemical Society meeting on Wednesday.

Ocean-borne plastic, such as that in the vast Great Pacific Garbage Patch, has traditionally been viewed as an environmental hazard due to the danger it can pose to sea life and birds. But to find out more about how plastic behaves when in the ocean, researchers acquired water samples from Japan, India, Europe, the United States, and other locations. The results? All the water samples were found to contain derivatives of polystyrene, a common plastic used in disposable cutlery, Styrofoam, and DVD cases, among other things [National Geographic News].

In another experiment simulating the breakdown of plastic in the ocean, researchers “found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future” [BBC]. As the plastic breaks down, it releases BPA, a compound shown to throw off rats’ hormone systems, along with another potentially harmful substance called styrene trimer. The toxins could not only pose a threat to marine life, but also to humans who eat seafood.

Still, some experts wonder if all of the ocean’s plastic really dissolves, since much of it may sink into the depths of the oceans where the water is generally calm, dark, and cold. For example, the plastic polystyrene is heavier than water, so it sinks. Because temperatures are much lower at the bottom of the ocean and there’s very little light to cause photodegredation, [ocean researcher Charles] Moore said it’s unlikely that the plastic would break down once it sunk. “Food doesn’t even biodegrade at the bottom of the ocean” [], Moore says. Meanwhile, pollution expert Joel Baker contends that the chemical releases are insignificant compared to the amount of water in the oceans. While he agrees that the plastic garbage in the ocean should be cleaned up, “There’s a little bit of hyperbole going on here,” Baker said [].

Related Content:
80beats: Ships Set Sail to Examine the Vast Patch of Plastic in the Pacific Ocean
80beats: Plastic-Devouring Bacteria Could Keep Soda Bottles Out of Landfills
80beats: BPA Won’t Leave the Public-Health Conversation–or Your Body
DISCOVER: The World’s Largest Dump: The Great Pacific Garbage Patch
DISCOVER: The Dirty Truth About Plastic

Image: flickr / Vagabond Shutterbug

  • Max

    There’s some good news out there in all this. Plastic bottles which are made from PET do not leach BPA’s. PET plastic is heavier than water…try this in the sink or pool, fill a water bottle or soda bottle with water and place it in the pool….it sinks pretty fast. PET will break down from sun light and wave mechanical action and when the bottle no longer holds air it will sink. We would rather see all bottles recycled, reused or disposed of properly. Our bottle, the ENSO biodegradable bottle is designed to recycle and if it finds its way into a landfill, it biodegrades. My personal opinion is that if all plastics were biodegradable many of the problems we are encountering with plastic would go away. Remember, there is a difference between plastics that are compostable, degradable or biodegradable. Compostable plastics such as PLA which is mostly made from corn, does not biodegrade. PLA will compost but only in a commercial composting site. Try finding a commercial composting site near you that will take PLA which is made of genetically modified corn. And let’s not forget degradable plastics. Degradable plastics break down, degrade, into smaller and smaller pieces, it doesn’t go away it just gets too small to see. Biodegradable plastic such as the ENSO bottle with EcoPure is designed to biodegrade in a microbial environment leaving behind biogases and humus. Biogases in a landfill are known as LFG’s and are being used to create clean energy. Clean energy from a plastic bottle…now that’s a novel idea.

  • Robert Lacy

    maybe microbes have found a way to devour plastic! Maybe there going to destroy all our plastic things!

  • Nova Terata

    So can we please just make everything from legos now?

  • David Colton

    It seems to me that ultimately we as a species will have to manufacture far less plastic, and reuse 100% of what we do manufacture. I’d recommend an obscure but brilliant little book on this topic, “Cradle to Cradle” ( ).

  • heylel shalem

    i’d like to point out that you can make completely biodegradable plastic that is just as good as plastic made from petroleum out of hemp. And there is no toxic chemical biproduct. Of course if you go that far you can make biodiesel out of hemp as well lolol.

  • Dan

    All plastics will decompose into harmless substances when the sun expands and envelopes the earth!

  • big steve

    Finally, a real environmental concern, not the pathetic attempt at taxing life (the lies around global warming).
    This, as well as depleted uranuim and gmo should be the priorities for people.

  • Tiwaz

    @ Max: PET plastic has the highest price on the recycled plastic market which leads me to believe that it gets recycled more often (recycling incentives, etc) and that the plastic in the ocean is of other varieties. Luckily Envion has created this beastly machine to turn plastic into gasoline for better or for worse:

    Also the particles that you speak of (too small to see) are called nurdles and are often mistaken for plankton by the wildlife. These nurdles end up destroying them because the fish and birds that consume them gain no nutrients by doing so and die of malnutrition. It’s also worth mentioning that the nurdles concentrate toxic waste molecules like DDT and when they make their way through the food chain and onto your dinner plate…. (DDT is actually a carcinogen)

    @ David: This sounds like a pretty controversial book judging by the reviews I read on the Amazon site. The concept of the book being recyclable (the book can be made into another book of the same design an infinite amount of times, or so they say) is beautiful in concept but is it possible? Who knows these days…

    I couldn’t get that good of a feel for what information was captured in the book but that one review by David Swanson is a bit off-putting from my perspective (student)….

    @ Dan: And so will all of us!… oh wait….

    @ All: There are so many possibilities for this global system we have created… choose your vision and die trying! (hopefully not tomorrow though)

  • Collins Pt.

    Biodegradable plastic and packaging is a modern necessity for our ever-endangered environment.
    Now PLA has been used to line the indoors of Paper Cups in place of the oil based lining additional usually used, create Plastic Cups, Plates, Carrier Bags, Food Packaging and even Nappies.
    Eco Pure is our proprietary blend of organic materials that does not modify the base resin to which it is added.

    Thanks a lot for your information

  • Tim Dunn

    Some readers may mistakenly come to the conclusion that polystyrene contains or breaks down into BPA. BPA is used with polycarbonate and epoxy only. Polycarbonate is the stuff that big water cooler bottles are made of, not small disposable water bottles, which are made of PET. Epoxy comes into contact with food primarily in the context of liners of ‘tin’ cans. Japan has discontinued the use of can liners made with epoxy/BPA, and the rest of the world should do the same. All plastics can be made biodegradable by the inclusion of a tiny amount of additive -see .

  • ChadFromPA

    What is described in the article IS NOT biodegradadation. This article’s title is misleading.

  • ChadFromPA

    It’s called Photodegradation.


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