There’s no denying the significance of water on the planet. After all, it covers 71% of the planet’s surface area. The role of plastics in the health of these waters came to the forefront with the discovery of the so-called Great Pacific Garbage Patch (GPGP) in 1997, existing between Hawaii and California. Scientists estimate its size at over 617,763 square miles.
About 46% is debris from fishing nets, with microplastics making up 94% of the pieces. These figures beg the question: How long does it take for plastic to decompose? The short answer is that researchers aren’t sure, but several factors come into play, including the type of material. Suffice to say that the semi-synthetic and synthetic debris floating in our oceans isn’t going away anytime soon. Let’s do a deep dive into the facts about ocean-borne waste.
Defining Plastic
Plastics contain synthetic and organic chemical compounds in long chains of molecules called polymers. The first synthetic plastic product was Bakelite, developed in 1907 by Leo Baekeland for industrial uses. This resin later became a fashion statement in the 1920s with jewelry. Many plastic items we use today come from fossil fuels. Others are made from recycled materials.
Plastic offers several advantages. First, it’s a recycled product, whether it’s sourced from petroleum by-products or post-consumer waste. It’s lightweight and can reduce greenhouse gas emissions by making vehicles less heavy and more affordable. It’s also durable, which ironically both adds and subtracts from its benefits.
Different Types of Plastic
Understanding the types of plastic is essential to put the decomposition time in perspective. The various kinds degrade at different rates. Each product has a specific resin identification code (RIC) that identifies the material. You may need to know this information for sorting your recyclables. The codes you’re most likely to encounter include:
- 01 Polyethylene terephthalate (PET or PETE) in cups or bottles
- 02 High-density polyethylene (HDPE or PE-HD) in milk jugs and heavier cups and bottles
- 03 Polyvinyl chloride (PVC or V) in flooring, siding, and other construction materials
- 04 Low-density polyethylene (LDPE or PE-LD) in six-pack rings and plastic bags
- 05 Polypropylene (PP) in food containers, vehicle parts, and other industrial uses
- 06 Polystyrene (PS) in Styrofoam and plastic flatware
Time Under the Sea
Of course, this list only skimps the surface of how manufacturers use plastic. Let’s put some estimated decomposition figures to use, using an apple core as our baseline. Surprisingly, it’ll take about 2 months for it to degrade, even though it’s an organic product. A plastic bag takes much longer at 10–20 years. Bear in mind different types exist, whether they’re single-use or compostable.
More durable materials carry far greater risks to the oceans and the environment. For example, disposable masks, plastic bottles, and disposable diapers can persist for an estimated 450 years. Fishing line is even longer at 600 years.
The oceanic environment and UV radiation play a significant role in decomposition. Eventually, larger materials break down into microplastics. Meanwhile, floating debris often becomes a habitat for marine life. Unfortunately, these colonies become targets for predators that will ingest the debris with the risks of foreign chemicals accumulating in their bodies.
Why It Matters
The problem for oceans and their marine life is the effects over time. As we’ve discussed, plastic doesn’t go away for some time. Scientists estimate that up to 8 million tons enter the oceans every year, compounding the issues. It’s worth noting that most of these materials are not coming from the United States.
A study investigating the sources of waste found that China, Indonesia, the Philippines, and Vietnam were the worst offenders. The United States came in at 20th on the list in 2010. The researchers projected it won’t even make it that far by 2025. The problem lies not as much with people’s use or littering but with the mismanagement of municipal solid waste contributing to ocean pollution.
Many US cities have enacted bans targeting bags and straws. Unfortunately, they do little to remedy the problem by the government leaders’ own admission. Instead, they’re more likely to lead to what scientists have called slacktivism. People make good-hearted gestures to help. Sadly, it makes some individuals less likely to do something that would make a difference. So, where does that leave us?
The Future of Plastics
It’s essential to separate facts from fiction for making informed choices and supporting effective legislation and solutions. It may seem like the best course of action is to clean up the oceans by filtering out the plastic. Unfortunately, it’s not that simple. Remember that these floating garbage patches have a constantly changing mass, making it difficult to just scoop the trash out of the water.
The National Oceanic and Atmospheric Administration (NOAA) has acknowledged as much. You also have to consider how disruptive it would be for marine life. Remember that these organisms live in a relatively stable environment. Filtering the debris would stress animals that don’t have the evolutionary capability of handling such changes. We’re also talking about a challenging international effort.
NOAA recommends two approaches. First, concentrate on the shorelines to keep plastic from heading out to sea. Clean-up projects can make a significant dent in what ends up in the oceans. Second, prevention is pivotal to getting the problem under control. Educating our children and offering assistance to other countries can help everyone manage waste better. Science also has a few tricks up its sleeve.
Bacteria to the Rescue
Identifying a way to speed up decomposition depends on finding something that can take on the task. A solution may be at hand with the accidental discovery and subsequent mutation of a plastic-eating enzyme. The result is a chemical that can decompose PET and polyethylene furandicarboxylate (PEF) materials. Scientists have since used genetic engineering to create a super enzyme that works faster.
The advantage of this type of approach is that it’s less invasive than cleaning the oceans manually. That makes it more environmentally friendly with less risk of collateral damage. Of course, further research is necessary to understand how it would work on a grand scale. However, the fact that a plastic-eating enzyme even exists is a monumental step forward toward managing our global plastic problem.
Final Thoughts
The enormity of the ocean-borne plastic issue means an equally significant solution. Perhaps Carl Sagan said it best when he remarked, “Extraordinary claims require extraordinary evidence.” That sums up the problem with plastics. The best action is to prevent waste from becoming a more formidable challenge. If you want to stop using plastic straws or bags, that’s fine.
However, a global effort is critical if we are going to save our oceans from the growing threat of plastic pollution. In the meantime, participate in a shoreline clean-up in your area. After all, there is only one planet Earth.
Featured Image Credit: Brian Yurasits, Unsplash