Invented a century ago, the polymeric material that at first seemed to make modern life so much easier has now become a major environmental problem
Plastic deposit run by recycling cooperative Reciclázaro in São Paulo
Léo Ramos Chaves
Almost everyone has seen or at least heard about the video of a turtle with a plastic straw stuck up its nose. The episode took place four years ago, when American marine biologist Christine Figgener and her colleagues were studying sea turtles in Costa Rica. While out at sea, they spotted one of the olive-green creatures with what looked like a giant tube worm in one of its nostrils. The researchers soon realized that it was a piece of a plastic straw, about four inches long, and decided to attempt to remove the object. The procedure, filmed by the group, showed the animal in agonizing pain. They posted the video online, where it quickly spread on social media and ultimately contributed to plastic straws coming to be seen as one of the great environmental villains. Since the video was first posted, it has been viewed 36 million times on YouTube and plastic straws have been banned in many cities around the world.
The event has become emblematic of a major problem afflicting the planet: the rampant consumption of plastic and the pollution generated by its improper disposal. It is estimated that 8.9 billion tons of virgin and recycled plastic have been manufactured since industrial-scale plastic production began in the middle of the last century. About two-thirds of this total, or 6.3 billion tons, has been disposed of as waste, while 2.6 billion tons is still in use.
This data is from the article Production, use, and fate of all plastics ever made, published in the journal Science Advances in July 2017. The research, considered one of the most thorough studies ever conducted on the issue, was led by physicist Roland Geyer of the University of California, Santa Barbara.
Experts are particularly concerned about the impact of plastic pollution on the oceans. It is estimated that more than 8 million tons of plastic waste are dumped in the sea every year, damaging marine life, fishing, and tourism. Huge islands of floating plastic can be found all over the planet—often brought together by circulating ocean currents called gyres. The largest, known as the Great Pacific Garbage Patch, stretches from the area between Hawaii and California all the way to Japan).
“One of the biggest problems is the complexity of the plastics in the oceans. We’re talking about fishing nets, plastics used in clothing, disposable products, microbeads, and nurdles [small pellets used as a raw material for plastic products]. Each uses different polymers that affect the environment in different ways, requiring different solutions,” environmental scientist Marcus Eriksen told Pesquisa FAPESP. Eriksen is cofounder and director of the 5 Gyres Institute, a California-based NGO focused on reducing ocean plastic pollution. “It would actually be possible to remove all marine plastic, but it would take so long and cost so much that it wouldn’t be worth it,” says Eriksen, considered one of the leading experts on the subject. The cost of the damage plastic causes to the marine ecosystem, according to the United Nations (UN), is estimated at US$8 billion a year. And this value is increasing.
One of the roots of the problem is the high public demand for plastic products. In 2016, annual production reached 396 million tons; in 1950, it was just two million tons. The amount of virgin plastic manufactured in the twenty-first century is equal in volume to the amount produced in the previous 50 years. Projections suggest that if the rate of growth is not slowed, the world will have to accommodate roughly 550 million tons of plastic waste by 2030.
Léo Ramos Chaves
Plastic bottles wash up on the shores of Santos Port (SP)Léo Ramos Chaves
It is easy to see why the use of these polymers, which mainly come from fossil materials such as oil, gas, and coal, has grown so rapidly. “Plastic is a lightweight, resistant, and durable material that provides innovative new developments for society,” says José Ricardo Roriz Coelho, president of the Brazilian Association for the Plastic Industry (ABIPLAST), which has 12,100 member companies with a total of 323,000 employees. “The use of disposables in healthcare, for example, prevents contamination and transmission of diseases. In the automotive sector, it has helped reduce vehicle weight, which increases energy efficiency. And plastic food packaging helps extend the shelf life of foods.”
“Society would be 200 years behind where we are now if plastic hadn’t been invented,” adds materials engineer and plastic specialist Luis Fernando Cassinelli, president of São Paulo–based innovation management consultancy Avantec BR Participações. “The planet wouldn’t be capable of supporting the current and future population without petroleum-based plastics. Alternative materials such as glass, metal, or paper would cause alternative problems, including increased energy and water consumption.”
Physicist Munir Salomão Skaf, from the Institute of Chemistry at the University of Campinas (IQ-UNICAMP), agrees that the versatility, low cost, and resistance of plastics to natural degradation processes have made it ubiquitous around the world, but points out: “These same properties make it a serious polluting agent, because it does not easily degrade in the environment.” Skaf is director of the Center for Research in Engineering and Computational Sciences, one of the Research, Innovation, and Dissemination Centers (RIDCs) funded by FAPESP, and his work is focused on making this degradation process easier. Alongside PhD student Rodrigo Leandro Silveira, he participates in an international group that has created an enzyme called PETase, which helps plastics degrade more easily (see article on page 29).
Plastic pollution, Skaf maintains, is a serious environmental problem that requires a three-pronged approach: significant reduction of use, replacement with new, easily degradable materials (with characteristics similar to synthetic plastics), and proper waste disposal through collection and recycling.
Single-use plastic products discarded immediately after their first use are the biggest concern for environmentalists. These products comprise between 35% and 40% of current production, including disposable cups, bags, straws, packaging, and cutlery. The rest is made up of long-lasting products, including a diverse range of items from cell phones, car parts, medical devices, and computer equipment to water and sewage pipes.
“We throw away more single-use plastics than nature can absorb,” says environmental management expert Sylmara Lopes Gonçalves Dias, from the School of Arts, Sciences, and Humanities at the University of São Paulo (EACH-USP). “If we used materials—even plastics—that lasted longer and weren’t disposed of so quickly, we could greatly reduce the number of products thrown in the trash.”
One of the biggest problems is that in nature, synthetic plastics take a very long time to degrade. Water and soft drink bottles made of PET (polyethylene terephthalate) take up to 400 years to decompose, while a plastic cup remains in the environment for at least 200 years. Experts say that the impact plastic has on the environment is inextricably linked to waste management in cities.
“About 80% of the plastic found in the oceans comes from land. The rest comes from human activities at sea, such as containers that fall from ships, lost or abandoned fishing nets, and trash from boats,” says marine conservation and ecology specialist Alexander Turra, from USP’s Oceanography Institute (IO). “In Brazil, a large part of the waste that reaches the sea is generated in irregularly occupied areas, such as coastal slums, where there is no garbage collection service. The problem is therefore linked to illegal housing and is essentially socioeconomic in nature.”
A study released this year by the nongovernmental organization WWF (World Wildlife Fund) showed that due to poor waste management, one-third of the world’s annual plastic waste becomes land or marine pollution. “The planet’s soil, freshwater, and oceans are contaminated with macro, micro and nanoplastics. Each year, humans are ingesting more and more nanoplastic from food and drinking water, with the full effects still unknown,” says the report “Solving Plastic pollution through accountability.”
The situation in Brazil
With serious deficiencies in its basic sanitation infrastructure, Brazil contributes to the effects of plastic pollution and suffers from it. According to the WWF, the country was the fourth largest producer of plastic waste in the world in 2016 with 11.3 million tons, surpassed only by the USA, China, and India. Of the plastic waste generated in Brazil, 10.3 million tons (91% of the total), was collected by urban sanitation services, but only 145,000 tons, equivalent to 1.28%, were sent for recycling. This is one of the lowest rates in the world, well below the global average of 9%, according to the WWF report, which used primary data from the World Bank’s What a waste 2.0 study, published in 2018.
The Brazilian plastics industry, however, has reservations about these figures. “The database used by the WWF is wrong, both regarding the amount of plastic recycled and the volume of waste produced in the country,” says chemical engineer Miguel Bahiense Neto, president of the Plastivida Socioenvironmental Institute of Plastics, an entity run by companies in the sector. According to him, Brazil consumed 6.1 million tons of plastic products in 2016. Of this total, 33% were short-life products that are discarded within a year, a category that includes packaging, bottles, cups, and bags. “The amount of plastic thrown away in Brazil is about 20% of the total stated in the WWF report,” says Bahiense.
A versatile polymer
Some of the benefits of plastic are difficult to replace
Food waste accounts for one-third of the world’s greenhouse gas emissions. Plastic containers combat waste by helping to prevent spoilage and ensuring food quality and safety
About 60% of the clothes produced worldwide are made of synthetic plastic fabrics. Providing enough clothes for the global population with natural fibers alone would be a major challenge
Every 150-kilogram reduction in weight allows a car to travel one extra kilometer per liter of fuel. Today’s car bodies include an average of 200 kilograms of plastic, replacing one ton of metal. The 800-kilogram reduction in weight results in a fuel-efficiency increase of 5 extra kilometers per liter
Increased longevity is attributed, among other factors, to the development of vaccines and the control of hospital-acquired infections. Disposable plastics played a key role in the latter
Reduced greenhouse effect
The decomposition of biodegradable packaging, such as corn starch, generates carbon dioxide (CO2)—a greenhouse gas. Plastics stored in landfills trap CO2, meaning it is not released into the atmosphere
Gabriela Yamaguchi, director of communications and engagement at WWF Brazil, explains that the industry’s results are different from those presented by the NGO because they are based on different data sources—the WWF focuses on estimating plastic waste in nature using data collected in 2016 by the World Bank. She points out that the amount of plastic waste produced in a given year is not limited solely to the disposable single-use materials made that year, as Bahiense suggests. “Long-life plastics sold in the past will eventually be discarded too, increasing the amount of waste generated in any given year,” says Yamaguchi.
Plastivida and ABIPLAST also contest the recycling figures. According to them, 550,000 tons of plastics were recycled in 2016. “If we take the volume recycled per year and compare with how much packaging and similar products are actually consumed in Brazil, we have a recycling rate of 25.8%,” said both organizations in a statement. But when comparing the volume recycled with total plastic consumption for the year, the rate drops and is close to 9%.
Despite the lack of agreement between the two sides, everyone agrees that the volume of plastic recycled in the country is still low. And this is a problem that needs to be tackled. “Brazil has to invest in policies that promote recycling and a circular economy, with every link in the chain involved, from large resin producers and plastic product manufacturers to vendors and consumers,” says chemical engineer José Carlos Pinto, from the Alberto Luiz Coimbra Institute for Engineering Research and Graduate Studies at the Federal University of Rio de Janeiro (COPPE-UFRJ). A circular economy is an economic system based on the reuse, refurbishment, and recycling of materials.
ABIPLAST president José Ricardo Roriz Coelho believes this is the way forward. “Selective collection and recycling are essential to solving the problem of environmental pollution, but these approaches face several obstacles, including the double taxation levied on the sector, the low supply of raw materials, and the high logistics cost of transporting materials. The recycling industry needs to be encouraged and better appreciated to help reverse this situation,” says the executive. In other words, the recycling industry remains unprofitable on a large scale and is not an attractive investment.
Researchers and environmentalists agree on the importance of strengthening the circular economy, but note that recycling is not a magic solution to all of the challenges of plastic waste. “It is not possible to tackle the problem by looking at postconsumption alone. There are plastics that are not naturally recyclable. Polymer additives and composite packaging made from both plastic and metal together, which is widely used in the food industry, are not mechanically recycled, and nor are contaminated or low-value items,” explains Yamaguchi from the WWF. While mechanical recycling is the most used method in Brazil and worldwide, there are two other types: chemical recycling and energy recycling. Both are most commonly adopted in developed countries.
Sylmara Dias of EACH-USP argues that it is important to also address the beginning of the production chain, encouraging environmentally friendly product designs. “We need a public policy that requires manufacturers to approve the design and materials used in new packaging, ensuring that they have no potential for pollution,” says Dias. “At the same time, we need to invest in new solutions, such as biological, biodegradable materials that nature can naturally regenerate.”
The many faces of plastic
There are almost one hundred different types of plastic, a material whose popularity has exploded worldwide since the middle of last century
It is difficult to imagine everyday life without plastics, even though they are a relatively recent invention. The first, called Bakelite synthetic resin, was only created in the first decade of the twentieth century. Its original purpose was to replace elephant ivory and bovine hooves and horns. Hard, heat-resistant, and durable, it is still used today to make power outlets, pan handles, tools, and telephones.
The industry gained momentum in the 1930s with the emergence of polystyrene, polyamide (of which nylon is the leading brand), and acrylic polymers, all of which are petroleum-based. But it was in the 1950s, after the end of World War II, that the material really began to gain popularity. Lycra and nylon fabrics that were cheaper, easier to wash, and didn’t need to be ironed started to compete with cotton and other natural fabrics. PVC, which is used in many building materials, cheapened construction processes, while manufacturers of household goods began to widely use melamine formaldehyde resin.
The public started to see plastic as a sign of wealth, associated with a new lifestyle and a new consumerist society. In the later decades of the twentieth century, demand for the material accelerated further thanks to the explosion of single-use plastics, disposable packaging, and plastic bags. These products flooded the market, mainly substituting household and personal goods previously made of other materials such as glass, wood, paper, and metal.
This was the case, for example, with PET bottles, which over time have almost completely replaced returnable glass bottles. Toys that were once made of wood started to be made of plastic instead. Consumers were easily won over by disposable plastic straws, cups, plates, and cutlery due to the convenience of not having to wash them—they were so cheap, they could simply be thrown away after being used.
Today, the vast world of plastics—a material made by linking molecules called monomers together into large molecular chains called polymers—includes nearly a hundred varieties and their derivations. They are divided into two groups. Thermoplastics (80% of plastics consumed) are malleable at high temperatures and recyclable. Thermoset plastics, meanwhile, decompose at high temperatures and are not mechanically recyclable.
The industry is dominated by the production of disposable plastic packaging that quickly becomes trash. In 2015, these products accounted for about 36% of the plastic produced worldwide. The construction sector accounted for another 16%, and the textile industry 14%.
Center for Research in Engineering and Computational Sciences (nº 13/08293-7); Grant Mechanism Research, Innovation, and Dissemination Center (RIDC); Principal Investigator Munir Salomão Skaf (UNICAMP); Investment R$23,737,036.75.
Over 700 research grants and scholarships have been awarded by FAPESP on this topic.
GEYER, R. et al. Production, use, and fate of all plastics ever made. Science Advances. July 19, 2017.