A new study has estimated that more than 250,000 tonnes of PPE and Covid-related plastics have entered the oceans.
Californian researchers developed a computer program that simulates the fate and movement of plastic waste.
They estimate that 8.4 million tons of pandemic-related plastic waste has been generated by 193 countries, from the start of the pandemic to August 2021.
Almost three quarters – 71 per cent – is likely to wash up on beaches by the end of the year, the model suggests.
Most of the offending Covid-related plastic is from medical waste generated by hospitals, the researchers say, which ‘dwarfs’ the contribution from PPE and packaging from online shopping giant like Amazon and eBay.
Covid-19 resulted in a rise in demand for single-use plastics like face masks and gloves. Researchers warn that rivers and oceans are home to a lot of this waste.
The term PPE refers to surgical gowns, disposable gloves, and masks. PPE includes all plastic packaging and plastic used in the manufacture of these products.
If properly disposed off, all can travel to the oceans and into rivers.
A team of researchers from Nanjing University and UC San Diego’s Scripps Institution of Oceanography led the new study. Data from 2020, when the pandemic began, to 2021.
In their paper, they state: “Plastic waste has been found to be a significant environmental threat to marine life.”
“The Covid-19 Pandemic caused an increase in demand for single-use plastics, intensifying the pressure on this out-of control problem.
According to this work, more than 8,000,000 tons of pandemic related plastic waste were generated worldwide. Additionally, more than 250,000 tons have entered the global ocean.
It is thought that this is a problem long-lasting for the ocean ecosystem and is most commonly found along beaches and in coastal sediments.
Covid-related plastics include masks, face shields (stock photo), test kits, disposable gloves and surgical gowns.
According to Yanxu Zhang, a study author at Nanjing University, the group created a virtual reality model for their research. It was based on Newton’s laws of motion.
Zhang said that the model “simulated how seawater flows driven by wind” and showed how plastics floated on ocean surface, and degraded from sunlight and plankton.
‘It can be used to answer “what if” questions – for example, what will happen if we add a certain amount of plastics to the ocean?’
The paper’s graphic shows how different pandemic-associated plastics are being released to the ocean. (A) Hospital medical waste; (B) Covid-19 testing kits; (C) PEPE and (D) packaging material for online shopping. (E) All of them together
This study revealed that the majority of plastic waste generated by the pandemic was entering the oceans from rivers.
73% of total plastics discharges from Asian rivers are in Asia, the three largest contributors being Indus and Shatt Al-Arab.
European rivers contribute 11 percent of the discharge. Other continents make minor contributions.
Researchers also examined the Covid cases against Covid-related waste plastic that flows into rivers. This was separated by continent.
Asia accounted for the greatest total for both – 31.2 per cent of the world’s Covid cases and 46.3 per cent of the world’s Covid-related plastic waste.
According to the authors, this is due to the fact that there are fewer Covid cases in developing countries like India and China than in developed nations in North America or Europe.
“When we did the math we were shocked to discover that medical waste was significantly higher than that of individuals and that a lot was coming from Asian countries even though this is not the location of most Covid-19 cases,” said Amina Schartup, Scripps Oceanography study co-author.
“The largest sources of excessive waste in the area were hospitals that had been struggling to manage waste before the pandemic. They just didn’t have the infrastructure necessary to deal with a situation like this.
The researchers estimated that more than 8 million tonnes of pandemic-related plastic waste has been produced worldwide. Although face masks may not be thought of by some as plastic, they do feature a layer of non-woven bonded fabric to filter microorganisms from the mouth and nose – commonly made of polypropylene, a type of polymer
According to the researchers, ocean plastic debris will likely settle on beaches within three to four year.
A smaller portion will go into the open ocean, eventually to be trapped in the centres of ocean basins or subtropical ‘gyres’ – large systems of rotating currents in each of the five major oceans.
Unfortunately, the world’s five subtropical gyres can go on to host garbage patches, comprised of PPE, litter, fishing gear and other debris.
According to the team, plastic waste transported into the Arctic Ocean is largely dead-end due to its ocean circulation patterns.
Subtropical “gyres” are systems that rotate currents through each of five oceans. They can collect rubbish due to their movement
Due to its harsh environment, high climate change sensitivity and vulnerability to extreme weather conditions, the Arctic ecosystem has been identified as being particularly fragile.
‘There is a pretty consistent circulation pattern in the ocean, and that’s why we can build models that replicate how the ocean moves – it’s just physical oceanography at this point,’ said Schartup.
‘We know that if waste is released from Asian rivers into the North Pacific Ocean, some of that debris will likely end up in the Arctic Ocean – a kind of a circular ocean which can be a bit like an estuary, accumulating all kinds of things that get released from the continents.’
This model indicates that approximately 80 percent of plastic waste that passes into the Arctic Ocean is likely to sink.
The authors call for improved management of medical waste at epicenters in order to reduce the amount of plastic waste entering the oceans. This is especially important in the developing world.
These calls also require that the public be aware of the negative environmental effects of PPE, and encourage development of environmentally-friendly materials.
A second approach is to develop ‘innovative technologies’ for improved plastic waste collection and classification.
Public members can help by recycling and disposing responsibly of Covid-related refuse.
This study is published in Proceedings of National Academy of Sciences today.