Tag Archives: plastics pollution

Are We Transgressing the Planetary Boundaries?

There are an estimated 350,000 different types of manufactured chemicals on the global market. These include plastics, pesticides, industrial chemicals, chemicals in consumer products, antibiotics and other pharmaceuticals….The rate at which these pollutants are appearing in the environment far exceeds the capacity of governments to assess global and regional risks, let alone control any potential problems..

In 2009, an international team of researchers identified nine planetary boundaries that demarcate the remarkably stable state Earth has remained within for 10,000 years – since the dawn of civilization. These boundaries include greenhouse gas emissions, the ozone layer, forests, freshwater and biodiversity. The researchers quantified the boundaries that influence Earth’s stability, and concluded in 2015 that four boundaries have been breached. But the boundary for chemicals was one of two boundaries that remained unquantified.

This new research takes this a step further. The researchers say there are many ways that chemicals and plastics have negative effects on planetary health, from mining, fracking and drilling to extract raw materials to production and waste management.

Some of these pollutants can be found globally, from the Arctic to Antarctica, and can be extremely persistent…Global production and consumption of novel entities is set to continue to grow. The total mass of plastics on the planet is now over twice the mass of all living mammals, and roughly 80% of all plastics ever produced remain in the environment. Plastics contain over 10,000 other chemicals, so their environmental degradation creates new combinations of materials – and unprecedented environmental hazards. Production of plastics is set to increase and predictions indicate that the release of plastic pollution to the environment will rise too, despite huge efforts in many countries to reduce waste.

Excerpt from Safe planetary boundary for pollutants, including plastics, exceeded, say researchers, Stockholm Resilience Center Press Release, Jan. 18, 2022

For an alternative view on planetary boundaries see NY Times Article, 2015

Global Microbiome Living on Plastics

The number of microbial enzymes with the ability to degrade plastic is growing, in correlation with local levels of plastic pollution. That is the finding of a study from Chalmers University of Technology, Sweden, that measured samples of environmental DNA from around the globe. The results illustrate the impact plastic pollution is having on the environment, and hint at potential new solutions for managing the problem.

The study analyzed samples of environmental DNA from hundreds of locations around the world. The researchers used computer modelling to search for microbial enzymes with plastic-degrading potential, which was then cross-referenced with the official numbers for plastic waste pollution across countries and oceans. “Using our models, we found multiple lines of evidence supporting the fact that the global microbiome’s plastic-degrading potential correlates strongly with measurements of environmental plastic pollution – a significant demonstration of how the environment is responding to the pressures we are placing on it,” says Aleksej Zelezniak, Associate Professor in Systems Biology at Chalmers University of Technology. 

More enzymes in the most polluted areas: In other words, the quantity and diversity of plastic-degrading enzymes is increasing, in direct response to local levels of plastic pollution. In total, over 30,000 enzyme ‘homologues’ were found with the potential to degrade 10 different types of commonly used plastic. Homologues are members of protein sequences sharing similar properties. Some of the locations that contained the highest amounts were notoriously highly polluted areas, for example samples from the Mediterranean Sea and South Pacific Ocean…

The researchers believe that their results could potentially be used to discover and adapt enzymes for novel recycling processes…“The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve. From there you could engineer microbial communities with targeted degrading functions for specific polymer types,” explains Aleksej Zelezniak.

Plastic-degrading enzymes increasing in correlation with pollution, Chalmers University of Technology Press Release, Dec. 14, 2021

Why Crabs and Mussels Love Plastic Pollution

The “Great Pacific Garbage Patch,” is considered the world’s largest accumulation of ocean plastic. It’s so massive, in fact, that researchers found it has been colonized by species — hundreds of miles away from their natural home. The research, published in the journal Nature, found that species usually confined to coastal areas — including crabs, mussels and barnacles — have latched onto, and unexpectedly survived on, massive patches of ocean plastic.  As suitable habitat made of plastics now exists in the open ocean, coastal organisms can both survive at sea for years and reproduce, leading to self-sustaining coastal communities on the high seas!

But the mingling of the neuston and coastal species is “likely recent,” researchers said, and was caused largely because of the accumulation of “long-lived plastic rafts” that have been growing since the middle of the 20th century. Just by itself, the Great Pacific Garbage Patch, located between California and Hawai’i, is estimated to have at least 79,000 tons of plastic within a 1.6 million-square-kilometer area. There are at least four other similar patches throughout the world’s oceans. Researchers expect that plastic waste is going to “exponentially increase,” and by 2050, there will be 25,000 million metric tons of plastic waste.  

For lead author Linsey Haram, the research shows that physical harm to larger marine species should not be the only concern when it comes to pollution and plastic waste. “The issues of plastic go beyond just ingestion and entanglement,” Haram said in a statement. “It’s creating opportunities for coastal species’ biogeography to greatly expand beyond what we previously thought was possible.” 

But that expansion could come at a cost. “Coastal species are directly competing with these oceanic rafters,” Haram said. “They’re competing for space. They’re competing for resources. And those interactions are very poorly understood.” There is also a possibility that expansions of these plastic communities could cause problems with invasive species. A lot of plastic found in the Great Pacific Garbage Patch, for example, is debris from the 2011 Tohoku tsunami in Japan, which carried organisms from Japan to North America. Over time, researchers believe, these communities could act as reservoirs that will provide opportunities for coastal species to invade new ecosystems. 

There are still many questions researchers say need to be answered about these new plastic-living communities — like how common they are and if they can exist outside the Great Pacific Garbage Patch — but the discovery could change ocean ecosystems on a global scale, especially as climate change exacerbates the situation. 

Excerpts from LI COHEN, There’s so much plastic floating on the ocean surface, it’s spawning new marine communities, CBS News, Dec. 2, 2021
BY LI COHEN