Dr. Wati Imchen
Geological Survey of India, Dimapur
Plastic is one of the most ubiquitous materials that have ever been introduced to the market and its abundance in the environment is evident.The versatilityof plastics in terms of its use, low production cost makes it the widely used and most discarded material in the world today. Consequently, plastic is fast replacing wood, glass, households and industrial materials. The ease and convenience associated with the use of plastics in our daily lives have come at a huge cost to the environment. It doesn’t decay easily, persists in the environment, pollutes the land, air, water, and eventually effecting biosphere including humans.Plastic is primarily synthetic mostly petrochemical products – although some are cellulose-based. The first plasticsmanufactured such as shellac, for gramophone records from the late 19th century, and bakelite was widespreadduringthe 1920s till 1940s and still in use today. Viscose silk and rayon, made from a cellulose base, have been manufactured since the early 20th century, and remain in production. Nylon, polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE) and polytetrafluoroethylene (PTFE) was introduced in the late 1930s and 1940s, polypropylene (PP) and expanded polystyrene foam in the 1950s, and polyethylene terephthalate (PET), from which most containers and bottles are now prepared. The unexpected global boom of plastic production and its utility can be seen in the exponential rise from less than 2 million tonnes manufactured in 1950 to the 380 million tonnes made annually today, which is equivalent to the weight of the entire human population. It is estimated that the current global annual production represents more than 40 kg of plastics produced annually for each of the 7 billion humans on the planet, approximating the total human biomass. Of the total annual production, only 10% is recycled, 12% incinerated and the rest piled up as garbage dumps on the land and oceans taking its own sweet time to degrade.In India, 80 % of total plastic consumption is discarded as waste and official statistics say the country generates 25,940 tonnes of plastic waste daily. Of which, at least 40% of this waste is uncollected. A report published in Science Advance, 2017 says that about 8.3 billion metric tonnes of plastics have been generated since the inception of the plastic production. The amount projected by 2050, based on current trends, is about 40 billion tonnes, which is enough to wrap 6 layers of cling film around the planet. It is an enormous industry, currently using approximately 8% of global oil extraction for its manufacture.
Plastic waste is now so ubiquitous in the natural environment that scientists have suggested it could serve as a geological indicator of the Anthropocene era. Anthropocene is an epoch of time in which humans have come to dominate many surface geological processes. There is a growing consensus that the beginning of the Anthropocene era is around mid-20th century and the post-WWII where an exponential upsurge of population, industries, and resource use took place. Besides other markers, plastics is another potential indicator, as this material has been manufactured in abundance since the mid-20th century, and its non-biodegradable nature and long-term preservation once buried in geological strata. Plastics,because of their remarkable utility and versatility are used in contemporary hygiene, as wrapping for foodstuffs, like disposable gloves, coats and medicine encapsulations used in hospitals, and in providing inexpensive clean water systems via water bottles and pipelines, components of many of our buildings, tools, and machinery.
The upsurge in plastic use globally is attributed to their lightweight, durability, versatile, flexible and relatively inert and thus proving to be much more mobile than any other human-made materials. They are insoluble in water, non-biodegradable, and persist over decades to centuries; plastic bags take about 10 to 1000 years and plastic bottles about 450 years. They are easily disposable and discarded in various ways after use; we see them widely around us as litter. They are easily transported by wind and water through the environment, where they accumulate. The scope and range of plastic contamination have become increasingly apparent over the last few decades, and it is now regarded as a major and growing environmental hazard.Plastics are divided broadly into macro- plastics (>5 mm) and microplastics (<5 mm). Macro plastics include everything that we would recognize as litter, such as plastic bags, bottles, fishing nets, plastic toys, piping, etc. On the contrary, microplastics are commonly invisible to the naked eye, particularly when mixed into sediment such as synthetic fabrics (clothing), microbeads, plastic pellets, etc; too small to be filtered out either by machine or sewage plant, can travel far by river and sea current and gets deposited within the sediments. On land, plastic litter is widely distributed especially in and around urban areas, along road corridors, andthe bulk of the microplastics are introduced to rivers via wind, storm sewers, and wastewater treatment plants.About 60% of plastic end up in landfill or the natural environment. It is estimated that the global agricultural consumption of plastics is about 2.5 million tons per year. The bulk of the plastic debris is sourced from land, and rivers act as conduits to enter their final sink: the marine or lake realms. Plastic pollutions are evident in freshwater ecosystems, such as lakes, and rivers. The ocean is the final resting place for a range of different types of human litter, though plastics form the bulk of it. Making up some 10% of all human refuse by weight, plastics are then selectively transported by wind and water to make up >50% of marine litter, and locally considerably more. Plastics enter the sea via rivers, from the point and diffuse sources along the shoreline dumping up to8.8 million metric tonnes annually (constitute 72% of the marine pollutants) and reach even the remotest and deepest part of the ocean. Of which, 236,000 tons are microplastics – tiny pieces of broken-down plastic smaller than your little fingernail. The amount of plastic in the ocean is set to increase tenfold by 2020. Concentrations of microplastics (mostly fibers), even at great depths (4869-5766 m) in the Kuril- Kamchatka Trench and adjacent abyssal plain have been recorded to be as high as 2000/m2. Even in the Indian ocean, which showed the lowest abundances, has been found to be 4 billion fibers per square km or 4000/m2. Researchers estimate that plastics would outweigh fish in the ocean by 2050.
Plastic pollutionis growing at an alarming pace making the environment toxic, but at the same time considered as contributors to the character of the recent and contemporary geological era. Plastic pollution has become a widespread phenomenon,both as macroplastics and microplastics, even in remotest environments such as that of the deep sea floor and the polar regions. In marine sediments, microplastics form superficially invisible, but potentially widespread markers. Once accumulated within sedimentary strata, plastic particles are potentially preserved as ‘techno-fossil’ that representsa permanent record of human presence on Earth. Stratigraphically, plastics within sediments represent a good indicator of the Anthropocene era, considering a mid-20th century as a beginning for this epoch.
Plastic pollution in Nagaland is not far from the rest of the country or world, as evident fromclogged drainagesby various forms of discarded plastics, strewn polybags, packaged water bottles, styrofoams, etc.It is indispensable to assess environmental pollution through rampant use of plastics in our State. However, it is unfortunate to note that waste generation data of our State is scanty. Limited data indicate that about 70-80 metric tonnes/dayof solid wastes are generated in Kohima (as per KMC), about 100 tonnes/day in Dimapur (DMC) and Mokokchung about 1800 kg/day (6,90,00,000 plastic bags/year) (MMC). These figures represent only the municipal area, and data beyond municipal area and other remaining districts are unknown. More than 90% ofthese wastes are non-biodegradable such as plastic carry bags, junk food, chips, guthka packet wrappers, single-use plastics/styrofoams, PET bottles, tetrapaks (juices and milk), etc.Appropriate disposal mechanism to managenon-biodegradablesolid wastes is the need of the hour. The Government of Nagaland has enforced therestrictions on the use of plastics (<50 microns) since December 1, 2018, in order to eradicate the menace of plastic and the serious environmental and ecological challenges, but withoutmuch visible impact.The stringent action against defaulters by the government vis-à-vis creating public awareness towards banning plastic is the key for effective implementation. The onus also lies with the public for proper segregation of their domestic waste prior to effective disposal management by the concerned department. However, it is disheartening to note that Kohima (Lerie) solid waste management (SWM) unit is the only SWM unit available in the entire State. Adopting the state-of-the-art technology for proper disposal mechanism, upscaling technical skills, adequate manual force and sufficient budget provision by the government could aid in reducing these menace. Ineffective management of plastics will lead to a myriad of long term adverse environmental and ecological problems. Burning of plastic in the open air is highly toxic due to the release of poisonous chemicals such asdioxins which can lead to cancer, respiratory problems to humans and animals. In landfills, it interacts with groundwater and generates hazardous chemicals and degrades the water quality. The durability and resistance to degradation of plastics make them nearly impossible for nature to completely break down. Microplastics are swallowed by animals or fish, mistaking them for food and thus can find their way onto our dinner plates. A study on aquatic toxicology in Malaysia confirms the presence of microplastics in 16 of 17 salt brands across eight countries. A study by Minnesota and New York Universities found that about 83% of tap water across the world is contaminated with microplastics. India (sample analyzed from Delhi) ranked third with 82% contamination.
It is laudable to note that myriad groups have been very active in the clean-up efforts of their towns and villages viz. Project 72 hours, the Church, governmental and non-governmental organizations, schools, colleges, etchave all put a concerted effort in the cleanliness drive.A partial solution to the plastic epidemic is bioplastics, which don’t use petroleum and degrade quickly. In recent years, several researchers have developed bioplastics made from Cassava (Indonesia), limestone derived SoluBag (Chile),etc. However, dearth ofextensive resources and agricultural area has been a major setback in spreading the technology globally. Lately, in a major breakthrough, the researcher from Tel Aviv University, Israelisdeveloping a new biodegradable plastic made from microorganisms (Haloferaxmediterranei)that feed on seawater algaewhich could be harvested in very salty water like the Dead Sea. These algae feed on seaweed which can be cultivated offshore and are then used to produce a polymer to create non-toxic and biodegradable plastics. Untilsuch mass production of bioplastics becomes a reality, we need to think and act locally to reduce or refuse the plastic usage in our daily life, as government alone cannot act in tackling this challenge.
Menace of plastic pollution has been considered as a geological marker of the Anthropocene age by the global geoscientists. It’s a reminderof the dark realityand callous treatment of humanstowards our own surroundings and nature. It is now imperative to choose our convenience over healthy and greener future for the next generation.
Dr. Wati Imchen