This article by Prof. Hiroshan Hettiarachchi was originally published in Groundviews, an award-winning citizen media website from Sri Lanka. An edited and shortened version is published here as part of a content-sharing agreement with Global Voices.
I was only a few years old when Sri Lanka opened its economy in the late 70s. The influx of plastics into the island was among the few visible changes I remember happening immediately after. Plastic was cheaper, lighter and attractive (at least colorful) compared to the things made of metal or wood that we had back then. Before long, many traditional wooden and metal household items were replaced by plastics. Bags, cups, plates, decorative items and furniture (a few years later) were among the most common examples. This was not a change only seen in Sri Lanka; the 1970s was the decade plastics became extremely popular around the world.
However, no one had any idea about what this new material would do to our waste stream. What waste stream? Life was much simpler back then; people didn’t have much to throw away, anyway. After paper and glass bottles were reused and metal items recycled — by those who did scavenging for a living — the little leftover garbage was mostly biodegradable. Plastics, on the other hand, are not easily degradable and there was no second-hand market for them either at that time.
The popularity of plastics made drastic changes to the waste composition and it took the world another two decades to understand the environmental pollution it had caused over the years. This pollution is twofold: it happens at a macro level as well as at a micro level. The macro issue of large mismanaged plastic items sitting on land or in our oceans and other water bodies are visible damage, something that may be fixed through proper and sustainable waste management. The micro issue is caused by the smaller plastic pieces — 5 mm or less in size as per the current definition. While some are as small as a few micrometers (1 micrometer = 1/1,000 millimeter), you may have to use the nanoscale to measure even smaller ones (1 nanometer = 1/1,000 micrometer). Their size makes microplastic pollution something extremely difficult to combat even with a good waste management system.
What exactly is microplastic pollution? To answer this question, let me take you to my mother’s kitchen in the late 1970s. The best observation I made as a kid was the chopping board. My mother’s wooden chopping board was soon replaced by a plastic one. Wooden or plastic, a chopping board always gets scratched with each knife cut, and over time we lose little pieces from its surface. While a wooden one may disintegrate at a steady rate, plastic disintegration gets worse with time.
The real question is what happened to these tiny little pieces that get detached from the plastics. The simple answer is that they either ended up in our food or in the pile of common trash in the backyard. In other words, we have been feeding microplastics to ourselves and to our environment from the backyard to the soils and water bodies. Although the country was flooded with plastic items, we were never educated on the limitations of plastics and we were never told that we shouldn’t be using the same plastic item for too long. We were not alone; the whole world was in the dark on this topic until the extent of microplastic pollution was discovered about 20 years ago.
Plastic has now become an integral part of our living and we are surrounded by thousands of plastic items that contribute to microplastic pollution. They are made of different materials/colors and can come in many different shapes, such as fragments, fibers, pellets, foams, films and more. Disposable utensils, water bottles, styrofoam cups and containers, hygienic products, some detergents, clothing, vehicle tires and cigarette buts are just a few examples.
Mismanaged plastic waste is one of the largest contributors to the issue. A majority of the microplastics are created by breaking down larger plastics into smaller ones and these small pieces can be as small as a few nanometers. What this means is that a majority of the microplastics in our environment are not even visible to us. They are also undetectable and unstoppable by the water and wastewater treatment facilities. As a result, most of our drinking water (including bottled water) contains some microplastics. Water and food are easy pathways for microplastics to enter human and animal bodies. Recent scientific research has proven the presence of microplastics in pretty much every organ in the human body, even in breast milk.
What exactly is the damage these microscopic particles can do to us and our environment? They are simply toxic to all living beings. Once ingested or inhaled, microplastics can roam around in the intestinal tract and the ones that are smaller than 150 micrometers can diffuse into the bloodstream and potentially disrupt immune response. A recent study reported that polystyrene particles that are 50 nanometers or smaller have the ability to enter the human brain as well. Microplastics in the environment can affect soil fertility and the soil organisms living in it. For example, the ability of microplastics to affect the development and mortality of earthworms has been established.
If plastic is this bad, shouldn’t we stop manufacturing it? There is no easy way to answer this question. Plastic has become a very useful, affordable and widely used material. It will have its place in the world until we find an alternative but there is no other candidate on the horizon to take its place: at least not yet.
We naturally tend to think that a proper waste management system (collection, treatment, and final disposal of waste) should be able to help us combat microplastics, like any other type of waste. Unfortunately, this is not the case. It can only be a partial solution, as microplastics are not only generated by the (mismanaged) plastic waste. Intentionally or not, we are also responsible for generating and releasing them to the environment.
The unintentional generation of microplastics is the most complex part of the puzzle. The chopping board example, the lint shed by clothes during washing and drying and the wear and tear of vehicle tires are some examples of unintentional generation done by us. It is not even possible to list down all probable ways of microplastic generation simply because we still do not know the complete story of it. However, we should at least try to prevent the ones we can understand and are able to stop. Until a better solution is found either to replace plastics or combat microplastics, the general rule must be to avoid any indiscriminate usage of plastics in our lives.