Climate and Environment
Plastic Pollution a Key Geological Marker: Present Scenario in Nagaland
Plastic is one of the most ubiquitous man-made materials that have ever been introduced in the market. The versatility of plastics in terms of its use, lightweight, durability, low production cost makes it the widely used in the world today. Plastic is primarily synthetic mostly petrochemical products – although some are cellulose-based. Consequently, plastic is fast replacing wood, glass, households and industrial materials. In late 19th century, the first plastics i.e. shellac was manufactured, followed by bakelite during the 1920s. Cellulose based viscose silk and rayon is in production since early 20th century. Nylon, polystyrene, polyvinyl chloride, polyethylene and polytetrafluoroethylene were introduced in the late 1930s and 1940s, polypropylene and expanded polystyrene foam in the 1950s. The global plastic production has shown exponential rise from <2 million tonnes (MT) in 1950 to 380 MT annually today. Of these, only 10% is recycled, 12% incinerated and the rest piled up as garbage dumps on land and oceans taking its own sweet time to degrade. In India, about 25,940 tonnes of plastic waste are generated daily and about 40% goes uncollected. Reportedly, about 8.3 billion metric tonnes of plastics have been generated since plastic production era. By 2050, based on current trends, about 40 billion tonnes plastics will be generated.
The ease and convenience associated with the use of plastics in our daily lives have come at a huge cost to our environment. They are non-biodegradable, contaminate the land, air and water, and persist in the environment over decades to centuries; plastic bags take about 10 to 1000 years and plastic bottles about 450 years. Plastic pollution has become increasingly apparent over the last few decades, and it is now considered as a major and growing environmental hazard. Plastics are broadly classified as macroplastics (>5mm, e.g. plastic bags, bottles, fishing nets, plastic toys, piping, etc) and microplastics (<5 mm, e.g. synthetic fabrics, microbeads, plastic pellets, etc).
The bulk of the plastic debris is sourced from land, and rivers act as conduits to the marine or lake realms. Plastic litter on land is widely concentrated around urban areas, along road corridors, and the 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. Reportedly, about 2.5 MT/year of plastics are consumed in agricultural sector globally. About 8.8 million metric tonnes of plastics are drained into the ocean annually. Of these, 236,000 tons are microplastics. The amount of plastic in the ocean is set to increase tenfold by 2020. Concentrations of microplastics, even at great depths (5766m) in the Kuril-Kamchatka Trench have been recorded as high as 2000/m2. In the Indian ocean, which showed the lowest abundances, has been found to be 4 billion fibers/km2. Researchers estimate that plastics would outweigh fish in the ocean by 2050.
Plastic waste is now so widespread 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 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. The widespread spatial distribution of plastic pollution, even in remotest environments like deep sea floor and the polar regions, reflects inherent character of the recent and contemporary geological era. In marine sediments, microplastics form superficially invisible, but potentially widespread marker. Once accumulated within sedimentary strata, plastic particles are potentially preserved as ‘techno-fossil’ that represents a 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 world. 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/day of 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% of these wastes are non-biodegradable such as plastic carry bags, junk food, guthka packet, styrofoams, PET bottles, tetrapaks, etc. The Government of Nagaland has enforced the restrictions on plastics use (<50 microns) w.e.f. December 1, 2018, in order to eradicate the menace of plastic on environment and ecology, but without much 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 could at least aid in reducing these menace. Ineffective management 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 as dioxins which can lead to cancer and respiratory problems. In landfills, it interacts with groundwater and generates hazardous chemicals and degrades the water quality. Microplastics are swallowed by animals or fish and thus can find their way onto our dinner plates. Lately, 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 indicate that about 83% of tap water across the world is contaminated with microplastics. India (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 NGOs, schools, colleges, etc. A partial solution of plastic epidemic is bioplastics. In recent years, researchers have developed bioplastics from Cassava (Indonesia), limestone derived SoluBag (Chile), etc. However, dearth of extensive resources has been a major setback in spreading the technology globally. Lately, in a major breakthrough, researcher from Tel Aviv University, Israel is developing new biodegradable plastic using microorganisms (Haloferaxmediterranei) that feed on seawater algae. These algae feed on seaweed which can be cultivated offshore and are then used to produce a polymer to create biodegradable plastics. Until such 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 is considered as a geological marker of the Anthropocene age. It’s just a reminder of the dark reality and callous attitude of humans towards its own surroundings and Mother Nature. It is now imperative to choose our convenience over greener future for the next generation.
Dr. Wati Imchen
Geological Survey of India