By Shubhangi Shah
While the government’s move to ban single-use plastic items starting July 1 is a step in the right direction, the menace of plastic is much larger, or should we say too small to even be detected by the naked eye. These are microplastics, the tiny plastic particles that form as a result of degradation of larger items, and also manufactured for specific industrial purposes. Some are as small as a few mm in size, and some are so small that they are visible only under a microscope. And this makes them a threat of gargantuan proportions. Because so omnipresent is plastic on the planet now that these tiny particles have even found their way to places unimaginable—from the bodies of marine organisms to Arctic and Antarctic snow, and from the deepest reaches of seas and oceans to the human bloodstream.
In an alarming discovery earlier this year, a group of scientists from the Netherlands found these tiny plastic particles in the human bloodstream. For this study, they collected samples from 22 healthy individuals. As many as 17 of them had quantifiable amounts of plastic particles in their blood. Although the direct impact of these on human health is currently unclear, “the particles are there and are transported throughout the body”, the researchers were quoted as saying in news reports.
They can also cause chronic inflammation, they further noted.
Dr Anu Pavithran V, a marine biologist and independent researcher, who is currently undertaking a study on the hormonal impact of microplastics in humans in a collaboration with the Indian Institute of Science (IISc), Bengaluru, told FE that microplastics might not affect humans directly but through added metals, mainly heavy metals. “When heavy metals bind with the surface of these microplastic particles, they end up impacting humans more,” she said. Although we do not know for sure, some hormonal impact has been found in some studies, she added. It is not only the bloodstream in our bodies that these pollutants have made their way into. These have also been found in the lungs, kidneys, spleen, and even the placenta, which provides oxygen and nutrition to the foetus. Dr Anu shared that currently we do not know exactly how these particles impact our health, but research is ongoing.
The research into the impact of microplastics has largely been around the marine environment. Studies involving humans have mainly relied on lab experiments, such as those carried out on mice or exposing human tissues to the pollutant. For example, a 2019 study showed mice, when fed microplastics, suffered from inflammation. Others found a low sperm count in them, suggesting an impact on their reproduction. Some in-vitro studies on human cells and tissues also showed toxicity.
From plastic to microplastic
British marine biologist Richard Thompson coined the term microplastics in 2004 to define tiny plastic particles of less than 5 mm in length after these were discovered on English beaches. “You can spot the larger microplastics as tiny micro coloured plastic bits. However, the smaller ones are invisible to the naked eye and can only be seen using a microscope,” said Dr Anu.
About how these are formed, she explained, “The larger plastic pieces we use get broken down into smaller and smaller particles upon exposure to several environmental factors like solar radiation, wind and ocean waves. These are called secondary microplastics.” However, there is another kind called primary microplastics, which are purposely manufactured. “These tiny plastic particles called microbeads are used in cosmetics, toothpastes, and other personal care products,” she explained, adding, “The secondary microplastics form a larger chunk of microplastic particles and are largely found in the marine environment.”
So which one is more contaminating, plastic or microplastic? “It is definitely the latter,” Dr Anu said, explaining that “since these are so tiny, they get transported anywhere, to the marine environment and the human bloodstream”.
Plastic within us
Humans created plastic and hence have contributed to microplastics. Indiscriminate use of plastic products and their careless disposal are some ways humans at an individual level contribute to the problem, the biologist explained. For example, plastic food containers shed microplastics in hot water, researchers found last year. Kettles and baby bottles do the same. Not just that, some pieces of clothing shed synthetic microfibres. Similarly, careless disposal of cosmetics and other personal care products that contain microbeads also contribute to the problem, Dr Anu explained. “Furthermore, they have also been found in the salt we use and mineral water,” she added.
Remotest corners have been hit too
In yet another alarming discovery recently, microplastic particles were found for the first time in freshly fallen snow in Antarctica. For this study, findings of which came out in the journal The Cryosphere, samples of snow were collected from 19 sites across the Ross Island region of the continent. Strikingly, microplastic particles were present in all of them at an average of 29 particles per litre. Not just that, 13 different types of plastics were found, the most common being polyethylene terephthalate, or PET, which is used for clothing, water bottles, and everyday items of clothing. It was found in 79% of the samples.
“The most likely source of these airborne microplastics is local scientific research stations, with the presence of polymers consistent with those used in clothing and equipment,” said P K Joshi, professor, School of Environmental Studies, Jawaharlal Nehru University (JNU), New Delhi. “However, modeling indicates potential long-range transportation for up to 6,000 km away,” he added. Not just water, these are also present in the air.
Terming the situation as ‘alarming’, the JNU professor opined that the finding strengthens the understanding that these microplastics transition between marine environment, terrestrial environment, and the atmosphere via something like a plastic cycle. Also, remoteness no more translates to inaccessibility or a barrier for pollutants anymore. “The presence also tells us about the mismanagement of waste in such pristine environment, which are the last resort for understanding the phenomenon of climate and many other ecological studies,” he added.
The most affected might still be the marine ecosystem. It is because a large chunk of microplastics ends up in the oceans, as per the US National Ocean Service. That might explain why most studies on these pollutants are centered around the marine ecosystem.
Commenting on the situation, Dr Anu said the “small marine fauna is exposed the most.” It is because “small fishes, molluscs, crabs, etc, may confuse them with food and end up ingesting them”. Humans eat fish and other marine animals too. So the marine pollutants can enter the human body through them, thus impacting health, Prof Joshi said. However, this does not mean that the non-fish eaters are protected. “Marine organisms are not just the only sources of microplastics for humans,” Dr Anu said. These are found in salt, bottled water, beer of some brands, and even air. “So everyone is exposed,” she added.
The impact of these particles on marine animals, their growth and reproduction has been researched.
Zooplankton is a tiny marine organism crucial to the marine food web. Research shows they grow slower and reproduce less successfully when exposed to microplastics. A 2019 study showed that adult Pacific mole crabs exposed to fibers lived shorter lives.
Prof Joshi says these particles “affect the food chain which is the basis of the movement of energy, matter, and stability of the marine ecosystem. The toxic effect of microplastic results in reducing food intake, delaying growth, and causing oxidative damage and abnormal behaviour. It also penetrates the biological barrier and accumulates in tissues, affecting life at the molecular level.”
What about climate change?
According to Dr Joshi, the microplastics in the Antarctic snow “may accelerate the melting of the cryosphere”, which is the frozen part of the planet. It can further lead to a rise in sea levels. Explaining further, he said, plastics are majorly made from fossil fuels. When discarded and exposed to solar radiation in both air and water, they emit greenhouse gases. “This is prominent with microplastics,” he said.
Plastic ban, other efforts
Terming the current state of marine microplastic pollution as ‘serious’, that has become a ‘global pollution incident’, Prof Joshi said some countries, including India, have responded by banning certain kinds of plastic to mitigate their leakage into the environment. “Bans have become an increasingly popular way of curtailing their use, but the available evidence indicates they do not reduce debris,” he said.
For curbing the microplastic menace, there is “a need for intergovernmental panels to debate and bring uniform steps to mitigate and tackle microplastic pollution wherein action-oriented commitments can be suggested and adopted,” the professor suggested.
In a global effort, the United Nations adopted a resolution earlier in March to end plastic pollution and forge an international legally binding agreement by 2024. In what was hailed as the most important international multilateral environmental deal since the Paris climate accord, the agreement aims to address “the full lifecycle of plastic from source to sea”, the world agency said.
What can be done?
With microplastics found in places unimaginable, one can understand the extent of the problem. Hence, what is needed are steps to tackle it before it blows up beyond control.
A group of researchers in China have developed a fish-shaped robot that swims through the oceans to collect microplastics. While the technology is developing, some steps can be taken. Both Dr Anu and Prof Joshi advocate the “controlled use of plastic”. They also highlighted the importance of the proper recycling of plastic waste. “In addition to the ban, the monitoring of microplastic pollution and design sanctions for microplastic spills and leakage could help in tackling this menace,” said Prof Pant.
On what we at an individual level can do about the situation, Dr Anu said, “A responsible use of plastics is the only thing individuals can do, as of now, to minimise microplastic pollution in the environment.” Hence, controlled use of plastics, their proper disposal, and switching to sustainable options are some steps that individuals can take.
1 Microplastics: What are they?
As the name suggests, microplastics are very tiny pieces of plastic less than 5 mm in length. Some are so tiny that they are invisible to the naked eye
2 Types of microplastics
- Primary microplastics Manufactured for use in cosmetic products, toothpaste, etc. These are called microbeads
- Secondary microplastics Mainly found in the marine environment, these are formed from larger plastic products we use in daily life. The latter comprises a greater chunk of microplastics
3 Where have they been found?
Just like plastics, microplastics are found everywhere—in oceans, seas, and snow, with the exception that these are even found in the air. Here are some places where they have been found:
- Deepest parts of the oceans (plastic bag used for groceries has even been found at the bottom of Mariana Trench)
- Arctic and Antarctica snow
- Near Mount Everest
- In the bodies of marine organisms
- In the human lungs and bloodstream
- Table salt
- Bottled water
- Beer of some brands
4 How do we contribute to it?
Humans created plastic and hence microplastics. However, there are ways by which we, as individuals, contribute to its release in the environment:
- Improper disposal of personal care products, which contain primary microplastics
- Excessive use of plastic, such as in the form of water bottles, bags, etc
- Careless disposal of plastic waste
- Careless fishery practices such as fishermen abandoning plastic nets and other pieces of equipment on beaches, which can end up in the sea
5 What is the solution?
Recently, a group of Chinese scientists developed a fish-shaped robot that can swim through the ocean and collect microplastic particles. However, the technology is still far from large-scale use. Until then, here are some ways to curb microplastic release in the environment:
- Minimising plastic use
- Recycling of plastic waste
- Controlled sewage treatment plants
- Once out in the environment, microplastics can be difficult to control. However, their release can be controlled to some extent through the aforementioned methods