The world has produced 8 to 11 billion metric tons of plastic since the 1950s—more than one ton per human! This amount surpasses the biomass of all terrestrial and marine animals, according to a 2020 study published in Nature.
Out of this, one-third was single-use plastic, approximately 3 billion metric tons, primarily used in packaging.
Estimates suggest that more than 6 Billion Tons of plastic have ended up as waste. Nine percent of the total plastic produced has been recycled; 12 percent to 19 percent has been incinerated; the balance has ended up in the atmosphere (nanoparticles), soil strata, water bodies, and oceans, causing irreversible environmental damage.
On average, a person ingests 5 grams of plastic weekly. One hundred forty thousand plastic nanoparticles are ingested while drinking one liter of water from a plastic bottle alone.
Plastic particles are found in the air we breathe and in human blood, colon, lungs, veins, breast, milk, placentas, and fetuses. Nanoparticles have also breached the blood-brain barrier.
This can have severe short- and long-term health consequences. Scientists are investigating the impact of micro and nanoplastics on human, animal, and plant health.
The extent of these harms has yet to be systematically assessed, the magnitude of their impact has not been fully quantified, and their economic costs have not been comprehensively counted.
Currently, there is no cheaper and functionally equivalent alternative to plastics.
In April 2024, members of UNEP will discuss a legally binding Draft Plastic Pollution Treaty. This is expected to be finalized by 2025.
Background
98% of plastics are produced from fossil fuels – oil and gas. A petroleum refinery or a petrochemical plant cracks naptha (A mixture of Hydrocarbons) to produce gases such as Ethylene, Propylene, Styrene, and Butadiene. These gases are monomers converted into complex polymers, which are long chains of molecules that create hundreds of different types and thousands of categories/blends of plastics, such as Polyethylene, HDPE, LDPE, PVC, PET, and more. Around 430 million tonnes of virgin plastic is produced annually, generating a whopping US $700 billion in revenue for large corporations such as Exxon Mobil, BP, Shell, Saudi Aramco, and other multinational companies. The industry is growing by 5 % per annum.
A large downstream industry processes plastics to make millions of products such as films, sheets, fibers, and moldings used in various sectors.
Plastics are ubiquitous; life would be unimaginable without them.
The food, beverage, and water supply chain relies heavily on single-use plastics for packaging, preservation, and transportation. Single-use plastic, packaging, and other discarded plastic have reached dramatic scale and volume, accounting for 1/3rd of total plastics consumed.
Plastics break up due to physical and temperature degradation into microplastics ranging from 5 mm to >10 µm ( Micrometers). Further degradation creates Nano plastic particles <10 µm.
Environmental Pollution
Atmosphere
Plastic pollution is caused by the creation of Micro and Nano plastic because of the decay in automobile tyres caused by road friction. Styrene Butadiene rubber is a plastic used in the majority of tyres. This pollution is difficult to control and quantify and is absorbed by humans from the air they breathe.
Water
About 8 million tonnes of plastic are estimated to enter the oceans annually. Plastic waste discarded on land runs off with rain into waterways or is directly dumped in rivers, ultimately reaching the oceans. Water bodies comprise different sizes of waste, including micro and nano plastics.
Knowledge of plastic pollution was initially gathered from marine ecosystems; however, ubiquity is similar across freshwater systems.
Some rivers show concentrations of microplastics that are orders of magnitude higher than those found in marine ecosystems.
Soil
Plastic waste is discarded/buried in land, improperly designed landfills, and partially incinerated waste mulches into soil, accounting for the most significant waste. As plastic breaks down, dangerous chemicals leach into soil and groundwater, affecting the plant ecosystem and finding their way into plants, vegetables, and fruits.
Animals, Marine Life
Plastic is also accumulating in living organisms. It has been reported in the ocean, freshwater species, and land animals, ranging from the Antarctic collembolan to African elephants. One thousand five hundred sixty-five species of animals have been identified as ingesting plastic for various reasons.
Plastic pollution accumulating in an area of the environment is considered “poorly reversible.” Should adverse outcomes in these areas arise due to plastic pollution, they will be practically irreversible. Potential impacts from poorly reversible plastic pollution include changes to carbon and nutrient cycles; habitat changes within soils, sediments, and aquatic ecosystems; co-occurring biological impacts on endangered or keystone species; ecotoxicity; and related societal impacts.
Today, many people rate plastic waste as a problem approaching climate change in its gravity. Analysis confirms that plastic pollution fits the exposure profile of a planetary boundary threat and that drastic action to reduce plastic pollution is the rational policy response.
Human Health
After ingestion through breathing, eating, and drinking, micro and nano plastics have been found in various parts of the human body.
Paolisso, a physician in Italy, and his colleagues tracked 257 people undergoing a surgical procedure that reduces stroke risk by removing plaque from an artery in the neck. The researchers put the excised plaques under an electron microscope. They saw evidence of microplastics — intermingled with cells and other waste products in samples from 150 participants. Chemical analyses revealed that the bulk of the particles were composed of polyethylene, the most used plastic in the world for food packaging.
On average, participants with more microplastics in their plaque samples also had higher levels of biomarkers for inflammation. They increase the risk of plaque rupture, spilling fatty deposits that could clog blood vessels.
Another study of more than 200 people undergoing surgery found that nearly 60% had microplastics or even smaller nanoplastics in a main artery. Those who did were 4.5 times more likely to experience a heart attack, a stroke, or death in the approximately 34 months after the surgery than were those whose arteries were plastic-free.
A recent study, “The Minderoo-Monaco Commission on Plastics and Human Health,” March 2023, by P J Landrigan and others, states
“Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer”.
Scientists are conducting various studies to evaluate the effect of plastics on human health in multiple countries.
Economic findings
As per UNEP and the study above, plastic pollution’s social and environmental costs range between USD 300-600 billion annually. However, these costs will likely underestimate the economic losses caused by plastics’ negative impacts on human health and the world’s environment. Unfortunately, the petrochemical and plastic manufacturing industry externalizes all the economic and social costs, which are then borne by citizens, taxpayers, and governments worldwide without compensation.
UNEP Plastic Treaty
The United Nations Environment Programme also concluded that the industry “inflicts a heavy burden on human health and environmental degradation, with the poorest in society facing the highest impacts while contributing the least to plastic overconsumption and waste.”
The UN Environment Programme (UNEP) published the draft text of the international legally binding instrument on plastic pollution, including in the marine environment, in 2023. Members from various countries will meet in April 2024 in Ottawa, Canada. It is hoped that the treaty will be signed by 2025. All parties agree it will be binding and present various mandatory and voluntary approaches. Some have likened its importance to that of the Paris accord on climate change.
What is the Way Forward
Consumer Education and Awareness
Plastic pollution is less well-known among the general public in developed countries and the Global South than climate change. Ironically, developed countries with a more educated and aware population are also the biggest polluters. In contrast, most of the Global South faces more pressing issues, and plastic provides the cheapest solution, especially for food and water storage. Awareness levels are low in these areas.
Therefore, each country must develop programs that target specific consumer profiles and create awareness. However, it may take years for the message to be absorbed and acted upon.
Produce less plastics
Reducing plastic production is crucial but also contentious due to plastic manufacturers’ significant profits and political power. Major Oil and gas multinationals generate US$700 billion dollars of revenue per year by producing plastics. The countries responsible for most plastic production, such as China and the United States, are not participating in limiting output.
Reuse or Recycle
UNEP, in a recent report looks at creating a Circular economy for Plastics. The circular economy is about increasing circularity, which means keeping products in use for as long as possible and finding ways to reuse their materials afterward.
Since the food industry is a big consumer, bottles, bags, and containers can be designed for reuse instead of single-use. This may entail a higher cost initially; however, the long-term impact could be significant.
Reusing products is the most efficient version of circularity, and it has been a common practice in many countries, such as collecting, cleaning, and refilling glass bottles. Buying foods in bulk and transporting them in reusable bags is also common.
Recycling plastic is one way to achieve circularity but poses several challenges. Plastic is designed to last long and consists of many molecules made up of long chains of carbon atoms. These molecules resist breaking apart, and each has unique chemical properties that require different approaches. Often, a single item, such as a potato chip bag, can be a frustrating mix of plastics, making it difficult to extract pure materials for reuse.
Currently, only about 9% of plastic is recycled. The process involves sorting usable types of plastic, melting them, and then solidifying them into pellets that can be used to create lower-grade plastics, such as bags and artificial lumber. There is a vast potential for increasing recycling infrastructure to reduce plastic waste.
Recycling waste is only possible with the active participation of local governments, municipal bodies, and pollution-conscious citizens. Plastic waste must be segregated at home, the workplace, or industry, transported to an appropriate recycling facility and correctly accounted for to avoid being thrown away or disposed of in landfills. Recycling plastic waste is energy-intensive, and the end product may have degraded physical and chemical properties. It is also possible that recycled plastic is more expensive than equivalent virgin plastic and may need to be subsidized.
Recycling infrastructure should initially be designed for prominent cities and towns with an optimal catchment of waste material. Collection, transportation, and material dumped into the recycling plant can be carried out by private contractors or municipal bodies. Proper accounting of waste is needed to avoid leakages. Recycling also entails some atmospheric pollution as it uses a lot of energy.
Export of Plastic Waste to Third World Countries
Until recently, many developed countries shipped plastic waste to third-world countries for recycling. The net export of waste from high-income to upper and lower-middle-income countries was 4 MMt/year.
India, China, Thailand, and Malaysia have banned waste imports in the past few years, while Vietnam will phase out the process by 2025. The shippers and recyclers turned Nelson’s eye to the processes involved, and a majority of the waste would be incinerated or put in landfills in the past.
More than half the plastic collected in the United States was shipped overseas; of the shipped material, as much as one-quarter was too contaminated to be recycled, according to a 2020 Science Advances study estimate.
To address the issue of plastic waste, the Basel Convention has undergone amendments. These amendments aim to improve the regulation of the cross-border movement of plastic waste. This means that any plastic waste or mixture of plastic waste produced by parties to the Convention that is intended to be transported must comply with the Prior Informed Consent procedure.
Countries will require innovative social and technology-driven solutions for Reuse, Recycling, and disposal to prevent pollution in the next 10 to 20 years.
Bio Plastics / Substitute Products
Bioplastics are plastic derived from renewable resources such as crops like corn, sugar cane, cotton, wood pulp, fungi, and other bio-based materials produced with the help of algae or microbes. Some bioplastics are designed to biodegrade and are derived from fossil fuel-based sources.
PHA, or polyhydroxyalkanoate, is a promising type of bioplastic made through bacterial fermentation of sugars and lipids. It is a bio-polyester that degrades into non-toxic components over a few months. However, other bio-based plastics, such as bio-polypropylene (bio-PP) and bio-polyethylene terephthalate (bio-PET), are chemically equivalent to conventional plastics and do not biodegrade, so they require traditional recycling.
Although biodegradable alternatives such as jute, hemp, and other materials exist, plastic is still much cheaper, making it economically unfeasible in the short term. However, this situation could change in the long term with progressive policies and economic incentives.
Extended Producer Responsibility
Extended Producer Responsibility (EPR) schemes require producers of plastic bottles, packaging, and other such products to provide funding for managing and recycling them after initial use. Nearly every country in Europe has an EPR program.
However, EPR schemes are currently limited in their impact since mid-stream producers, such as bottlers and beverage manufacturers, have done the most to embrace and pay for them.
To make a more significant difference, the programs must bring in upstream producers, such as Exxon, Dow, and Saudi Aramco, who create virgin plastics and polymers.
Well-designed EPR schemes can cover the total costs of ensuring Extended Producer Responsibility. These schemes place the responsibility on producers for end-of-life disposal of packaging.
In France, the fees collected through EPR schemes for packaging reduce the waste management burden of municipalities by over 50%. Belgium also has one of the most successful EPR schemes, with over 80% recycling rates for packaging.
The United Kingdom has recently introduced a new tax that applies to plastic packaging produced in or imported into the country that does not contain at least 30% recycled plastic.
Bacteria / Microorganisms to decompose plastic waste
Enzymes are biological catalysts that can create a chemical reaction. Enzymes in microorganisms can be used to decompose plastic waste. Unlike many industrial chemicals, enzymes work at relatively low temperatures. They are choosy about which molecule they interact with—enabling an enzyme to target a single plastic in a stew of polymers. Scientists began hunting for such enzymes in earnest in 2016 after Japanese researchers analyzing mud near a plastic recycling factory found a bacterium with an unusual appetite for plastic called Ideonella Sakaiensis. This microbe can produce two enzymes that can break down PET plastic. It is the first microbe to be identified that can survive solely on plastic as its food source. The organism fed on polyethylene terephthalate by breaking it into its building blocks, terephthalic acid and ethylene glycol.
Linda Zhong Johnson, a researcher from MIT, is currently working on creating more efficient versions of these enzymes by manipulating microbial genes. She has identified one mutation that results in an enzyme up to 30% more efficient than its original form.
Muhammad Reza Cordova is scouring for treasure among water bottles, plastic bags, and plastic foam cups that choke the beaches, reefs, and mangrove forests around Jakarta, Indonesia. He hopes to find organisms that can help solve the decomposition problem in the microbe-rich slime coating some of that trash.
Cordova collects slime samples and brings them back to his lab at Indonesia’s Research Center for Oceanography, where he cultures the microbes and feeds them only plastic to see what thrives. Cordova delves into the muck at the roots of mangrove trees. Microbes that feed on tough mangrove leaves would have had decades to evolve the ability to break down the plastic bags that cling to the roots.
Any promising microbe that Cordova finds are shipped to the Centre for Enzyme Innovation at the University of Portsmouth in the UK, supervised by McGeehan. His team crystallizes promising enzymes and uses X-ray crystallography to peer into their structures, deciphering how they bind to polymers and help break their chemical links.
They are scouring databases of bacterial genomes for DNA sequences, signaling potential plastic-cracking enzymes. Researchers then use computers to model how the proteins might be artificially improved. The goal is to modify the genes that encode the natural enzymes to make them into powerful plastic-busting tools. The team has already altered the enzyme the Japanese researchers uncovered to make it more efficient.
Researchers across the globe are on the same quest. They are looking for plastic-munching microbes in searing hot springs in Yellowstone National Park and remote island beaches in the Pacific Ocean.
Carbios, a biotechnology company in France, has opened a pilot plant that uses an engineered enzyme to break down and recycle PET. This enzyme was first discovered in compost. The company is constructing a full-scale facility scheduled to open in 2025.
Moving from the laboratory to a recycling factory requires overcoming technical and economic hurdles in an industry with razor-thin profits and where new plastic can be cheaper than recycling.
Removing Hazardous Chemicals used in Plastics
To tackle the pollution crisis, it is necessary to eliminate many problematic plastics, such as Polyvinyl Chloride (PVC), and replace them with sustainable alternatives. PVC, commonly used to make pipes and other materials, breaks down into toxic chlorine-containing components and cannot be recycled.
Chemicals are essential to plastics as they provide additives and processing aids. However, some chemicals (>7,000) can be released into the air, water, and soil. After analyzing a fraction of these chemicals, it has been found that 3,200 chemicals have adverse effects due to their potential to mimic, block, or alter the actions of hormones, reduce fertility, and other impacts on health.
UNEP Global Plastic Treaty
The document was made available in 2023 in preparation for Plastic Treaty, which will take place in April 2024 in Ottawa, Canada. It is hoped that the Treaty will be in place by 2025.
The first part includes options for the preamble, objective, definitions, principles, and scope.
The second part outlines various polymers. EPR schemes, emissions and releases of plastic throughout its lifecycle, waste management, and trade. Detail existing plastic pollution, just transition, transparency, tracking, monitoring, and labeling.
The third part relates to financing, capacity building, technical assistance, and technology transfer.
The fourth part covers national action, implementation plans, compliance, reporting on progress, and periodic assessment and monitoring. International cooperation, information exchange, awareness raising, education and research, stakeholder engagement, and health aspects are covered.
The fifth part deals with the governing and subsidiary bodies of the future treaty and its secretariat.
Conclusion
Plastic pollution is a severe environmental problem that has yet to capture the mass imagination of Governments and Citizens.
Given the lack of practical and economically feasible alternatives, humans will continue to consume plastics at an increasing rate.
Plastic pollution has caused irreversible damage to the atmosphere, soil strata, and water bodies.
The damage to human, animal, and plant health is significant, and it is virtually impossible to stop the ingestion of micro and nanoplastics.
There are no large-scale, commercially viable technical solutions for bio-degradation, recycling, and disposal.
Implementing the UNEP Treaty and its enforcement will take decades, particularly in the Global South, where people are most affected.
The first climate change meeting was in 1972, also known as the Stockholm Conference. Over fifty years have passed since then with no substantial progress. Will, UNEP’s be able to deliver on the Plastic Treaty in time.
Governments worldwide need to do more to address this planetary scourge.
Educated and aware consumers, as well as media interest, can bring about meaningful change.
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