Macro Problem

THE DEEPEST POINT on earth is the Mariana Trench and the highest is Mount Everest. In recent years, they have found something in common—microplastics. These are plastic, just really tiny bits less than 5 mm. They might have been around for the same time as plastics but the world only got a term for it 20 years ago in 2004, and that was because its prevalence was being noticed. Even then no one had anticipated the sheer scale of its ubiquity. In 2018, a study found between 200 and 2,200 pieces of microplastics per litre in the Mariana Trench. The study observed: “The hadal zone is likely one of the largest sinks for microplastic debris on Earth, with unknown but potentially damag­ing impacts on this fragile ecosys­tem.” Meanwhile, at the Everest, the presence of microplastics was lesser than in the Mariana Trench at an average of 30 pieces per litre but still a constant feature now.

Last year, researchers at the Indian Institute of Technology, Patna, collected rainwater from two locations in the city over two months and found that mi­croplastics were literally raining down. They were present in the air and the rain brought it down. An article in the journal Nature said, “Polyethylene terephthalate and polypropylene are the most common of nine types of microplastics detected in rainwater samples. Previous studies report airborne microplastics in 17 sites across Asia, Europe, and North America.” All this is still understandable but mi­croplastics are now known to be not just all around but in areas no one could have imagined. Like inside our bodies.

Satish Sinha, associate director of Toxics Link, an environmental protection organisation, says that many studies have shown the presence of microplastics in just about every human organ, including placenta. Toxics Link itself conducted studies that found microplastics in agricul­tural soil and tap water. They thought it was necessary to find out how microplastics were entering the body. There were some obvious routes. “One possibility is food, the other dermal and the third through the air we breathe. We knew that water has it because we had done tap water testing. So we thought let us study some of the common food items that we consume,” says Sinha. The two items that the organisation zoned in on was salt and sugar. Last week Toxics Link came out with a report that said that microplastics were present in both these common food items. The reason to select salt was that it was commonly available and also came from a marine environment which is often the most affected by microplastics. And sugar, because they were keen to know whether microplastics get absorbed from the soil by some of the crops.

For the study, they bought 10 brands of different types of salt—table, rock, sea, etc—and five brands of sugar. All were found to have microplastics. Their press release gave details of the findings: “The quan­tity and size of microplastics varied in different salt samples ranging from 6.71 to 89.15 pieces per kg of dry weight and 0.1 mm to 5 mm, respectively. They were found in the form of fibres, pellets, films and fragments. The microplastics found in the sugar and salt samples were of eight different colours: transparent, white, blue, red, black, violet, green and yellow. The size of the microplastics found in different sugar samples varied from 0.1 mm to 5 mm and were mostly in form of fibres, followed by films and pellets.” India is not alone either in microplastics being found in salt and sugar. Australia, Europe, the US and Japan have all found them.

Microplastics come into being in a couple of ways. First is by the degradation of regular plastic. Bags, bottles and just about anything that is made out of plastic deteriorate over time and are released into the environment. These are called secondary microplastics. There are also the primary ones, which are manufactured as microplastics and used in products. One of their major use cases is in personal care products. “Your toothpaste, shampoo, face scrub, all have microplastics. When you wash it off or have a bath, it goes through the wastewa­ter system into rivers and other places,” says Sinha.

Because much of the waste ends up in the rivers or oceans, marine life is where the presence of microplastics is most acute­ly felt. These get into fish. A number of negative effects are said to be induced in marine life by its consumption. These range from damage to tissues to impairment in reproduction to even loss of immunity. An interesting experiment was conducted last year by the US government agency, National Institute of Standards and Technology. They took two batches of rainbow trout. One was exposed to a virus. The other was exposed to the virus, too, but also imbued with microplastics, like nylon fibres and polystyrene. The agency then compared the mortality of the two batches. The latter batch was found to have 6.4 times higher chances of dying. The paper stated: “Further, we found that mortality correlated with host viral load, mild gill inflammation, immune responses, and transmission potential. We hypothesize that micro­plastics can compromise host tissues, allowing pathogens to bypass de­fenses. Further research regarding this mechanism and the interplay between microplastics and infectious disease are paramount, considering microplastics increasing environmental burden.”

THERE IS NOT much known conclusively about what effect microplastics have on human beings but the evidence is slowly emerg­ing that they might have many adverse types of fallout. In March, for instance, the New England Journal of Medicine published a paper that looked at what it might be doing to the heart. The researchers took 304 people, studied their heart vessels, and followed up with them for 34 months. Those in whom microplastics were detected in the plaque in their arteries were found to have a much higher likelihood—more than four times—of cardiac events. An­other 2021 study found a link between microplastics and Irritable Bowel Syndrome (IBS). Researchers looked at the faeces of IBS patients and found much more microplastics than what was prevalent in those without the ailment.

Studies have only shown a correlation so far, signaling the need for more research. As a Nature Medicine article observed, “Although these studies did not demonstrate a causal link between the presence of MNPs (micro nano particles) and disease, they underscore the need to accelerate research on this topic. Among the most pressing questions are the amounts of MNPs that are absorbed through ingestion, inhalation or skin exposure, the amounts of MNPs that accumulate in different tissues over the lifetime of a person, and how the different char­acteristics of MNPs— including their chemical composition, size and shape—affect those tissues.”

There is so much plastic being produced in the world that it goes beyond the ability of wastewater systems to handle. This happens annually and the day is marked as Plastic Overshoot Day for that year. In 2024, this is going to be September 5. As a precursor to the event, a Swiss environment body EA Earth Action came out with a report recently. One of the things revealed in it were the nations adding the most microplastics into waterways in the world. India released 391,879 tons and was placed second on top after China. When Toxics Link did a study of the waters of the Ganga river by collecting samples from different regions, it found the presence of microplastics in all the samples. This is the same water that people used for drinking.

As the problem is now becoming too big to ignore, India and the rest of the world are beginning to take steps to ad­dress it. For instance, the Food Safety and Standards Authority of India (FSSAI) re­cently launched a project that would de­cide on a protocol to detect microplastics and find out their prevalence. Belatedly so, at least mapping is now being done to dis­cover their extent. The food safety body has roped in a number of institutions to carry out the project, like the Indian Institute of Toxicology Research in Lucknow, Central Institute of Fisheries Technology in Kochi, and the Birla Institute of Technology and Science in Pilani. Meanwhile in Novem­ber, all the nations in the world will gather together in Busan, South Korea, to agree on a treaty to reduce plastic pollution. The idea is to make it binding on everyone to do something on this front. Microplastics are expected to feature as an element in the treaty.

The technology to combat microplastics is very nascent but Sinha thinks that eventually some measures will have to be put into place to stem the influx of the pollutant. Like capturing them off the wastewater system or filtering them out of tap wa­ter. But most of all, people must revert from their dependency on plastic. Sinha says, “Plastic was an unknown material till about 100 years back. So obviously it is how human beings have dealt with it across the world that has made it omnipresent. It is for us to decide and act a bit more responsibly as to how do we consume, produce and dispose plastic. It is for all of us to demand from our governments and industry to deal with plastics more responsibly.”

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