A new era of global pollutants

About eight years ago, I started my first job working at a major supermarket retailer. My job at the cash register involved packing and bagging each customer's shop. This was when we only had plastic bags available, and we used them like no tomorrow. Shops worth hundreds of dollars were bagged solely with plastic. Customers would often ask to have their shop double-bagged or even triple-bagged.  

Fast forward to today’s supermarkets, and you’ll find bags are now made primarily from recycled materials and carry a price. In other parts of the world, like Germany, providing plastic shopping bags in a store has been completely banned. Despite this paradigm shift in industrial plastic use, the prevalence of plastics in the environment is widely evident. This prevalence has only one link: humans.

Human pollution and plastics

While plastics are considered a tangible pollutant, their smaller counterpart, microplastics, are of increasing concern. Microplastics are plastics less than five millimetres in size (think smaller than your pinky finger). They arise from the degradation of larger macroplastics: plastic packaging, synthetic fibres like nylon and more. Surprisingly, microplastics can be found almost anywhere – our waterways, the air we breathe, hygiene products and even the food we eat.

In the 19^th century, before the plastic revolution, one of the most critical environmental threats was uncovered. It was found that, in the UK, the pH of rainwater in industrial areas had lowered and that leaves from nearby forests affected by rain appeared to deteriorate. This phenomenon, termed ‘Acid Rain’, was proposed to be a result of the increased SO₂ emissions around Europe at the time. The scientific community and public at large subsequently ignored these claims. Only after the industrial revolution did the issue of acid rain start to spark attention and provoke public and scientific consideration.

In line with microplastics, we are at a stage where this environmental threat is being engrained into the atmosphere. Reports show that microplastics can travel through rain and wind and pass onto remote, sparsely uninhabited areas. Indeed, atmospheric microfibres have recently been documented in regions and mountains of Europe and the Arctic. This transport of pollutants across the air is being termed ‘Plastic rain’.

However, the impacts of this plastic rain on the environment are yet to be quantified and uncovered. Indeed, the widespread impact of microplastics on the environment is only starting to be touched.

Current impact of microplastics    

It is known that microplastics can carry contaminants such as trace metals and potentially harmful organic chemicals. The polymers that comprise certain microplastics have also been classified as carcinogenic and mutagenic. Although, the long-term risk of these microplastics on human health is unclear.

It is estimated that 8-14 million tonnes of microplastics currently lie on the sea floor alone. Marine life can mistake microplastics for food or involuntarily consume them. Evidence shows that smaller species, like clams, mussels and zooplankton, are ingesting more microplastics than the larger species. Microplastics pose a serious threat to the soil ecosystem on the land because they leach toxic chemicals and transport hazardous pathogens.

What’s threatening is that we are yet to see the repercussions on the food chain and these ecosystems. While no regulations currently exist to control microplastic removal, we may still have time to act.

We cannot escape the reality that we live in a world of microplastics. But how big is the problem? And how can we fix it if we can’t see it?

Article written by PhD student, Fernando Tinoco.