posted on 11/27/2022 06:00 / updated on 11/27/2022 10:59
(credit: DOMINQUE FAGET)
After the climate change conference, the United Nations (UN) is meeting again this week to try to find solutions to a problem that threatens human health and that of the planet. From tomorrow to December 2, the first intergovernmental session will take place with the aim of developing a legally binding international instrument on plastic pollution. The event, in Uruguay, will discuss the treaty with governments, the private sector and civil society, which should enter into force in 2024.
The historic decision on the negotiations was taken in February, at the Assembly of the United Nations Environment Program (UNEP), in Nairobi. On the occasion, Inger Andersen, Executive Director of UNEP, stated that this will be the most important multilateral international agreement since the climate agreement, signed in Paris, in 2015. and that means incorporating different points of view to arrive at a framework that allows us to meet a series of economic, social and environmental objectives.”
The treaty will take into account the complete useful life of the plastic, from the source of manufacture to the arrival of the pollutant in the oceans, including the incorporation of additives. According to the UN body, the production of the material has increased exponentially in recent decades, with an average production of 400 million tons per year — a number that should double in 2040.
The lifecycle of plastic, a by-product of fossil fuels, is considered environmentally aggressive from production to disposal. In nature, it takes four centuries for the material to decompose and, in the natural degradation process, very dangerous microparticles are formed when inhaled and ingested, found in the atmosphere and oceans. It is estimated that 700 animal species are directly affected, many of which are on the endangered list.
According to Sophie Davison, a researcher at the European Center for the Environment and Human Health at the University of Exeter, in the United Kingdom, there is little knowledge about the impact of microplastics on humans. “Plastic pollution is one of the fastest growing environmental challenges on our planet,” she says. “However, while the harm to marine life is well understood, the impact on human health remains unclear,” she says.
There are clues, however, that pollution by this material could have serious implications. In April, British scientists reported the detection of 12 different types of microplastics in samples of lung tissue taken during surgery. The polymers were also identified in the bloodstream and even in the placenta. Although more studies are needed to investigate the negative potential of particles in the human body, some research shows that they can cause cell death and allergic reactions.
thousands of substances
As the first session of the UN’s intergovernmental committee on plastic pollution approaches, scientists warn that the treaty needs to take into account the diversity and complexity of the chemicals that make up different types of plastic. In an article published in the journal Environmental Science & Technology Letters, researchers from several international institutions expressed concern about the direction of the negotiations if the heterogeneity of the material is ignored in the text of the agreement.
According to Zhanyun Wang, a scientist at the Swiss Laboratory for Materials Science and Technology and lead author of the paper, a recent study identified more than 10,000 substances that can be used in the manufacture of plastic, resulting in products with a wide range of chemicals. “Such diversity and complexity of plastic formulations comes with a number of negative impacts and challenges. Among them, concern about adverse effects on human health and the ecosystem,” he says. But it’s not just that. “Equally important, but often overlooked, is that the diversity of chemicals in plastics can pose many challenges to current and anticipated technological solutions for tackling plastic pollution.”
The scientist argues that the diversity of substances in different plastic products makes waste streams incompatible, which can reduce the quality of recycling and lead to the formation of toxic substances that require safer handling measures. According to Antonia Praetorius, assistant professor at the University of Amsterdam and co-author of the article, heterogeneity in manufacturing has another negative impact: the more complex, the less safe, and therefore less suitable for long-term use.
“One proposed solution to counteract the plastic waste caused by single-use plastics is to increase the use of more durable plastics, to allow for multiple reuse cycles,” says Praetorius. “The more complex the chemical composition of these plastics, however, the more difficult it is to guarantee their integrity and safety during the useful life of the product.”
The authors of the article argue that, by identifying a set of safe chemical additives that fulfill the necessary functions for the manufacture of the material, it will be possible to find simpler and more standardized formulations. They also make practical recommendations on how the treaty can include mechanisms to reduce the complexity of chemicals in plastic production. “Not only will this allow for the phase out of hazardous chemicals from plastic production, but it will also enable the societal transition to a circular plastic economy,” they said in the text.
Not even Antarctica escapes
Scientists find plastics in different parts of Antarctica
Even in the largely uninhabited Antarctica, scientists have found synthetic plastic fibers in the air, water and sea ice. The researchers from the University of Oxford analyzed samples collected during an expedition on the frozen continent and, in all of them, they detected fibrous polyester, mainly from textiles. Most of the microplastics were in the atmosphere, indicating that seabirds and other local animals may be inhaling the material.
“The issue of microplastic fibers is a problem that is reaching even the last remaining untouched environments on our planet”, says Lucy Woodall, researcher from Oxford and co-author of the study, published in Frontiers of Marine Science. “Synthetic fibers are the most prevalent form of microplastic pollution globally and addressing this issue must be at the heart of plastic treaty negotiations,” argues Woodall, the first scientist to reveal the existence of plastic at the bottom of an ocean, in 2014.
With software that modeled the trajectory of the air in Antarctica, the researchers found that the areas with the highest number of fibers received winds coming from the south of South America. According to Woodall, the fact reveals that the Antarctic circumpolar current and the polar front associated with it are not, as believed, acting as an impenetrable barrier, which would have prevented the entry of microplastics in the region.
“Ocean currents and winds are the vectors for plastic pollution to travel around the world, including the most remote corners”, adds Nuria Rico Seijo, co-lead author of the research. “The transboundary character of microplastic pollution provides further evidence for the urgency and importance of a strong international plastics pollution treaty,” she says.
The team also found that the concentration of microplastics is much more abundant in sea ice than in other types of samples. This indicates that pollutants are being trapped during the creation of the ice layer, every year. “Sea ice is mobile, can travel great distances and reach the permanent ice shelves of Antarctica, where it can be trapped indefinitely with its collected microplastic pollutants”, says the article.
The researchers carried out studies on sediment samples collected at depths of 323m to 530m below the surface of the Wedell Sea, where microplastics were detected. “Once again, we’ve seen that plastic pollution is being carried over vast distances by wind, ice and ocean currents. Our research results collectively demonstrate the vital importance of reducing plastic pollution globally,” notes Woodall.
For her, the newly published findings “increase the urgency of a binding and globally agreed treaty to prevent microplastics from entering the environment, especially the oceans”. In addition to measures taken by policy makers, the scientist highlights that, individually, it is also possible to contribute to the reduction of plastic pollution (see box). (DUST)
Goal must be ambitious
“The treaty target must be ambitious and meaningful, we are calling on the UN to pursue a target of 0% on the rate of new plastic pollution by 2040. To achieve this, policy makers, business, researchers and society at large must be radical efforts in developing a coordinated global strategy. Currently, there is ambiguity about what ending plastic pollution really means. For the treaty to work, it is vital that there is a single objective and an agreed strategy.”
Steve Fletcher, director of the Global Plastics Policy Center
from the University of Portsmouth, USA
» Every day, approximately 8 million products
to the oceans.
» 12 million tonnes of plastic are dumped into the ocean every year.
» Plastics account for 80% of all marine debris studied.
» 100,000 marine mammals and turtles and 1 million seabirds are killed annually by marine plastic pollution.
» 90% of plastic is produced from raw material obtained from fossil oil and gas.
» The production of one ton of plastic generates up to 2.5 tons of carbon dioxide.
How to help reduce plastic pollution
1- Fill the washing machine: the more space for the fabric to move in the wash, the greater the shedding of microfibers.
2 – Wash at 30°C: gentle cycles and lower temperatures reduce microfiber shedding.
3 – Abandon the dryer: they generate about 40 times more microfibers than washing machines.
4 – Choose natural fiber textiles such as cotton, linen, hemp.
Sources: Surfers Against Sewage; UNEP; university of oxford