Featured Image: Rich Carey

The global anti-plastic discourse was born from the visual and palpable effects of plastic pollution. A six-pack ringed turtle, a plastic ensnared dolphin or the waste-filled belly of a whale insights a visceral response that no issue purely founded in academia can.

This is the great failure of plastic and the champion of the green movement – an associative image that draws an emotive response. This is particularly evident of plastic pollution in marine environments.

“Plastic is the most prevalent type of marine debris found in our ocean”

Provocative images can, for example, drive swathes of people to their local beach in tireless dedication to a regular ‘beach clean-up’ for which no compensation is received. And still, at a long day’s end, an individual will look back on the events of the day and take in a breath of self-satisfaction.

The invasive nature of plastic on Our visual perception fuels the anti-plastic movement. But, emerging research has revealed a dilemma.

What if, before days end on the beach clean-up, a net-touting scientist were to pass by only to describe your hard-cleaned beach as filthy? That your days efforts accomplished little more than a face-lift. What if this operation removed little more than a fraction of the plastic on said beach? What if most plastics on said beach remained untouched because they are imperceptible to humans?

The classic idiom ‘out of sight and out of mind’ does not just describe a human tendency to remove from thought that which is out of sight. It also describes how sight motives action. In this case, sight motivates a denouncement of plastic.

Enter, Microplastics.

Microplastics are not a new thing. Scientists and businesses have utilised them in everyday products since at least the late 1960s. But, only recently is the magnitude of their impact being realised.

So, what are these troubling denizens of a largely imperceptible world?

Microplastics are a subset classification given to plastic particles measuring 5mm wide or less. This class is broken again into two subcategories: primary and secondary.

Primary microplastics are intentionally produced as a raw material for use in pharmaceutical and cosmetic products; as an abrasive component; or as an additional component in many other industrial products.

Secondary microplastics are a by-product. It results from the fragmentation of larger plastic products, such as the breakdown of beach litter or the shedding of synthetic fibres in laundry. For example, synthetic clothing can release up to 700,000 microfibers during the average wash cycle.

Whether primary or secondary, all microplastics share at least one commonly concerning characteristic – durability.

The durability of microplastics and plastics in general, is the favoured property that spurred human interest. Now, this property presents one of the biggest threats to marine environments. As structural pollutants, they do not easily biodegrade and are highly persistent in marine environments.

“Nearly all plastic that has ever been released into the environment still exists today” – Aaron Jackson

The Problem.

The study of microplastics is an emerging field in the sciences and has only recently gained traction. Hitherto research ventures have been poorly funded and the field is understudied. There is little known about the impacts of microplastics on marine life and food webs, for example, and the exact severity of their presence in the world’s marine environments.

As a fault of, the extensity and density of microplastic concentrations in the world’s waters is constantly being revised up, as study after study finds new regions with increasingly higher concentrations.

The findings of a study published in Nature Geoscience concerning the River Tame near Manchester took samples from 40 sites and found upwards of 500,000 particles in these areas alone. The same study discovered that during heavy flooding, around 40 billion particles are washed into the ocean.

A study in British Columbia found microplastic concentrations of 9,200 particles/metre² in seawater. A separate study found that the North Pacific Gyre, otherwise known as the Great Pacific Garbage Patch, increased from 331,809 pieces per square kilometre in 1999 to 19,912,037 in 2014.

Studies estimate a global microplastic index of around five trillion pieces. (Although this figure is believed to significantly underestimate the true circumstance).

So?…

While studies are limited, the effect of microplastics on marine life is being realised. To many of these creatures, the true nature of microplastics is indiscernible, and it is mistaken for food or consumed unintentionally. Herein lies the danger.

Filter feeders, for example, are particularly susceptible to unintentionally ingesting microplastics. Creatures like whale sharks and manta rays swallow hundreds of thousands of cubic metres of water every day. This introduces microplastics into their body on a grand scale. In the Sea of Cortez, whale sharks were found to ingest 200 pieces of plastic per day. In the Mediterranean Sea, fin whales swallow about 2,000 microplastics per day.

Large filter feeders are not the only affected creatures. Microplastics effect all levels of the food web. Zooplankton have been observed ingesting up to 30.6 μm of microplastics – a hefty meal by the standards of Zooplankton.

The effects of microplastics on the body is an equally understudied field. But, evidence is emerging to suggest that the ingestion of microplastics is hazardous to marine animals. Known effects that occur from the ingestion of microplastics include nutritional stress, digestive system blockage, entanglement, inflammation, asphyxiation and more.

More concerning still is emerging evidence that suggests microplastics transport and bind to toxic chemicals, like phthalates; concentrates chemicals, like pesticides, in localised areas; and transports bacteria present in the surrounding seawater or that has been acquired during the transition from land to sea. All of which may be transferred into the body and have adverse toxicological effects.

Small enough microplastics have been observed crossing the cell membrane and causing tissue damage; ingesting these chemicals and pollutants can affect the physiology of the host organism; persistent exposure can compromise a species fitness et cetera.

In the current timeframe of awareness and with the minimal breadth of information available to us, it is difficult to surmise the precise scale and breadth of potential issues. But, precedents set by past and current anthropogenic problems raise concerns around several potential effects, including bio-magnification and chronic toxicity. The concerns don’t stop here.

The most confronting insight for many is the realisation that microplastics have long been impacting humans. While indirectly affecting humans through bioavailability, microplastics in the food web has transpired into direct consumption of said plastics. For example, a study in Europe found that occasional consumers of shellfish may ingest up to 11,000 microplastics a year from this meal alone.

A review of 250 bottles from 11 leading water distribution brands found that 93 percent of the samples had on average 315 microplastics per litre. One sample contained more than 10,000 particles per litre.

Our future.

Plastic pollution has been synonymous with the recent history of man. As our societies have continued to move forward founded on ineffective waste management strategies and outdated perceptions, the issues of plastic pollution are worsening.

Each year we produce more than 330 million metric tons of plastic globally. There are few adequate ways to dispose of said waste. Landfills simply concentrate plastics in a localised area and kick the can down the road. And, this most popular of methods collects microplastics that eventually reach marine environments through the airways during the breakdown process.

The failings of other disposal methods are far less… subtle. In the Pacific Ocean, nestled between California and Hawaii, an expanse 3 times the size of France contains a massive garbage patch. It boasts the highest recorded concentration of plastic, comprising an estimated 80,000 tonnes of the material.

A seemingly endless and unbelievable list of the impacts humans have had on the environment through plastic pollution are easily searchable. But, even without research, it seems common sense that plastic pollution has been disastrous and requires drastic action.

The answer to halting future pollution is simple: stop using plastics. The solution to our past is nowhere near as simple. For in the same manner as diamonds, plastics are forever. (Diamonds are not actually forever. It eventually breaks down into graphite).

What habits have you changed to limit your plastic usage?

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