EPA to weigh regulating common plastic as hazardous waste

Read the full story at E&E News.

EPA may finally classify a commonly used plastic as hazardous waste, following a long legal struggle with advocates.

The Center for Biological Diversity said this afternoon that it has reached a deal with EPA over polyvinyl chloride, more well known as PVC or vinyl, following a decade of back-and-forth. Under the agreement, EPA must assess within nine months whether PVC constitutes hazardous waste under federal law.

This company is capturing methane—then using it to make forks and straws

Read the full story at Fast Company.

On this week’s episode of World Changing Ideas, we explore the concept of methane removal, and speak to one company doing it, Newlight Technologies. Cofounder and CEO Mark Herrema walks us through how Newlight is not only removing methane from the atmosphere, but simultaneously generating an everyday product, called AirCarbon, with the potential to reduce plastic use.

The sustainable applications of chitosan

Read the full story at AZO Materials.

A mini-review has been published in the journal Polymers on chitosan’s potential for sustainable applications in multiple industries. Researchers from Spain, India, Iran, and China have contributed to the review.

Do you toss biodegradable plastic in the compost bin? Here’s why it might not break down

Shutterstock

by Bronwyn Laycock, The University of Queensland; Paul Lant, The University of Queensland, and Steven Pratt, The University of Queensland

Over one-fifth of all plastic produced worldwide is tossed into uncontrolled dumpsites, burned in open pits or leaked into the environment. In Australia, 1.1 million tonnes of plastic is placed in the market, yet just 16% (179,000 tonnes) is recovered.

To deal with this mounting issue, the Morrison government last week announced A$60 million to fund plastic recycling technologies. The goal is to boost plastic packaging recycling from 16% to 70% by 2025.

It comes after 176 countries, including Australia, last month endorsed a United Nation’s resolution to establish a legally binding treaty by 2024 to end plastic pollution.

This is a good start – more effective recycling and recovery of plastics will go a long way to solve the problem.

But some plastics, particularly agricultural plastics and heavily contaminated packaging, will remain difficult to recycle despite these new efforts. These plastics will end up being burnt or in landfill, or worse, leaking into the environment.

“Biodegradable” plastic is often touted as an environmentally friendly alternative. But depending on the type of plastic, this label can be very misleading and can lead environmentally conscious consumers astray.

Shovelling backyard compost
Don’t expect everything labelled ‘biodegradable plastic’ to break down in your backyard compost bin. Shutterstock

What are biodegradable plastics?

Biodegradable plastics are those that can completely break down in the environment, and are a source of carbon for microbes (such as bacteria).

These microbes degrade plastics into much smaller fragments before consuming them, which makes new biomass (cell growth), and releases water, carbon dioxide and, when oxygen is limited, methane.

However, this blanket description encompasses a wide range of products that biodegrade at very different rates and in different environments.

For example, some – such as the bacterially produced “polyhydroxyalkanoates”, used in, for instance, single-use cutlery – will fully biodegrade in natural environments such as seawater, soil and landfill within a few months to years.

Others, like polylactic acid used in coffee cup lids, require more engineered environments to break down, such as an industrial composting environment which has higher temperatures and is rich in microbes.

Some biodegradable plastics only break down in industrial compost facilities. Shutterstock

So while consumers may expect that “compostable” plastics will degrade quickly in their backyard compost bins, this may not be the case.

To add to this confusion, biodegradable plastics actually don’t have to be “bio-based”. This means they don’t have to be derived from renewable carbon sources such as plants.

Some, such as polycaprolactone used in controlled release drug delivery, are synthesised from petroleum-derived materials.

What’s more, bio-based plastics may not always be biodegradable. One example is polyethylene – the largest family of polymers produced globally, widely used in flexible film packaging such as plastic bags. It can be produced from ethanol that comes from cane sugar.

In all material respects, a plastic like this is identical to petroleum-derived polyethylene, including its inability to break down.

Confusion and greenwashing

In 2018, we conducted a survey of 2,518 Australians, representative of the Australian population, with all demographics collected closely matching census data.

We found while there’s a lot of enthusiasm for biodegradable alternatives, there’s also a great deal of confusion over what constitutes a biodegradable plastic.

Consumers have also become increasingly concerned over the practice of “greenwashing” – marketing a product as biodegradable when, in reality, its rate of degradation and the environment in which it will decompose don’t match what the label implies.

So-called “oxo-degradable plastics” are an excellent example of why the issue is so complex and confusing. These plastics are commonly used in films, such as agricultural mulches, packaging and wrapping materials.

Chemically speaking, oxo-degradable plastics are often made from polyethylene or polypropylene, mixed with molecules that initiate degradation such as “metal stearates”.

These initiators cause these plastics to oxidise and break down under the influence of ultraviolet light, and/or heat and oxygen, eventually fragmenting into smaller pieces.

There is, however, some controversy surrounding their fate. Research indicates they can remain as microplastics for long periods, particularly if they’re buried or otherwise protected from the sun.

Indeed, evidence suggests oxo-degradable plastics aren’t suited for long-term reuse, recycling or even composting. For these reasons, oxo-degradable plastics have now been banned by the European Commission, through the European Single-Use Plastics Directive.

Plastic bags are often made from polyethylene, which can come from cane sugar. Shutterstock

We need better standards and labels

The new government funding for plastic recycling technologies targets waste that’s notoriously difficult to deal with, such as bread bags and chip packets.

However, this still leaves a substantial stream of waste that’s even more challenging to address. This includes agricultural waste dispersed in the environment such as mulch films, which can be difficult to collect for recycling.

Biodegradable and bio-based plastics have great potential to replace such problematic plastics. But, as they continue to gain market share, the confusion and complexity around biodegradable plastics must be addressed.

For starters, a better understanding of how they impact the environment is needed. It’s also crucial to align consumer expectations with those of manufacturers and producers, and to ensure these plastics are appropriately disposed of and managed at the end of their life.

This is what we’re investigating as part of a new training centre for bioplastics and biocomposites. Our goal over the next five years is to improve knowledge for developing better standards and regulations for certifying, labelling and marketing “green” plastic products.

And with that comes greater opportunity for better education so both plastic producers and people who throw them away really understand these materials. We should be familiar with their strengths, weaknesses and how to dispose of them so we can minimise the damage they inflict on the environment.

Bronwyn Laycock, Professor of Chemical Engineering, The University of Queensland; Paul Lant, Professor of Chemical Engineering, The University of Queensland, and Steven Pratt, Associate Professor, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sustainability by design

Read the full story from North Carolina State University’s College of Design.

Students are gaining real-world experience while reducing waste in a new project sponsored by Eastman. The company challenged NC State industrial design seniors in the College of Design to create consumer products with sustainability top of mind. 

The students’ design concepts will help Eastman have deeper conversations with consumer brands who want to be more sustainable but may not know exactly how to launch such products. “The goal is to help more brands adopt sustainable materials in order to make a significant impact on the environment,” said Anders Ludvigsen, market development manager at Eastman.

Light, oxygen turn waste plastics into useful benzoic acid

Read the full story from Cornell University.

Chemists have discovered a way to use light and oxygen to upcycle polystyrene — a type of plastic found in many common items — into benzoic acid, a product stocked in undergraduate and high school chemistry labs and also used in fragrances, food preservatives, and other ubiquitous products.

Tarleton researchers work to remove microplastics from wastewater

Read the full story from Tarleton State University.

Tarleton State University researchers led by Dr. Rajani Srinivasan have demonstrated that combinations of food-grade plant extracts, including those from okra, aloe, cactus and psyllium, have the power to remove microplastics from wastewater.

Findings were presented at the March 20-24 virtual spring meeting of the American Chemical Society.

Study finds twice as many cellulose fibers as microplastics in the Atlantic Ocean

Read the full story at Green Car Congress.

A study by three French institutes—Ifremer, the University of Bordeaux and the IRD (a public research institution)—has found that the surface water of the Atlantic Ocean is twice as polluted by cellulose fibers as it is by microplastics. This study, based on measurements taken from an offshore race boat, also shows that the North Atlantic is more affected by plastic pollution than the South Atlantic and questions the dynamics of the subtropical gyre (area with a high concentration of microplastics) since the pollution levels measured there are lower than expected.

Disease-causing parasites can hitch a ride on plastics and potentially spread through the sea, new research suggests

The sticky biofilms that form on microplastics can harbor disease-causing pathogens and help them spread. Tunatura/iStock via Getty Images Plus

by Karen Shapiro, University of California, Davis and Emma Zhang, University of California, Davis

Typically when people hear about plastic pollution, they might envision seabirds with bellies full of trash or sea turtles with plastic straws in their noses. However, plastic pollution poses another threat that’s invisible to the eye and has important consequences for both human and animal health.

Microplastics, tiny plastic particles present in many cosmetics, can form when larger materials, such as clothing or fishing nets, break down in water. Microplastics are now widespread in the ocean and have been found in fish and shellfish, including those that people eat.

As researchers studying how waterborne pathogens spread, we wanted to better understand what happens when microplastics and disease-causing pathogens end up in the same body of water. In our recent study published in the journal Scientific Reports, we found that pathogens from land can hitch a ride to the beach on microscopic pieces of plastic, providing a new way for germs to concentrate along coastlines and travel to the deep sea.

Aerial shot of boat floating through plastic pollution on water
Microplastic pollution has negative consequences for human, animal and environmental health. Yunaidi Joepoet/Moment via Getty Images

Investigating how plastics and pathogens interact

We focused on three parasites that are common contaminants in marine water and seafoods: the single-celled protozoans Toxoplasma gondii (Toxo), Cryptosporidium (Crypto) and Giardia. These parasites end up in waterways when feces from infected animals, and sometimes people, contaminate the environment.

Crypto and Giardia cause gastrointestinal disease that can be deadly in young children and immunocompromised individuals. Toxo can cause lifelong infections in people, and can prove fatal for those with weak immune systems. Infection in pregnant women can also cause miscarriage or blindness and neurological disease in the baby. Toxo also infects a wide range of marine wildlife and kills endangered species, including southern sea otters, Hector’s dolphins and Hawaiian monk seals.

To test whether these parasites can stick onto plastic surfaces, we first placed microplastic beads and fibers in beakers of seawater in our lab for two weeks. This step was important to induce the formation of a biofilm – a sticky layer of bacteria and gellike substances that coats plastics when they enter fresh or marine waters. Researchers also call this sticky layer an eco-corona. We then added the parasites to the test bottles and counted how many became stuck on the microplastics or remained freely floating in the seawater over a seven-day period.

Biofilms are vast communities of microbes that can form on almost any surface, including your teeth.

We found that significant numbers of parasites were clinging to the microplastic, and these numbers were increasing over time. So many parasites were binding to the sticky biofilms that, gram for gram, plastic had two to three times more parasites than did seawater.

Surprisingly, we found that microfibers (commonly from clothes and fishing nets) harbored a greater number of parasites than did microbeads (commonly found in cosmetics). This result is important, because microfibers are the most common type of microplastic found in marine waters, on coastal beaches and even in seafood.

Plastics could change ocean disease transmission

Unlike other pathogens that are commonly found in seawater, the pathogens we focused on are derived from terrestrial animal and human hosts. Their presence in marine environments is entirely due to fecal waste contamination that ends up in the sea. Our study shows that microplastics could also serve as transport systems for these parasites.

These pathogens cannot replicate in the sea. Hitching a ride on plastics into marine environments, however, could fundamentally alter how these pathogens move around in marine waters. We believe that microplastics that float along the surface could potentially travel long distances, spreading pathogens far from their original sources on land and bringing them to regions they would not otherwise be able to reach.

On the other hand, plastics that sink will concentrate pathogens on the sea bottom, where filter-feeding animals like clams, mussels, oysters, abalone and other shellfish live. A sticky biofilm layer can camouflage synthetic plastics in seawater, and animals that typically eat dead organic material may unintentionally ingest them. Future experiments will test whether live oysters placed in tanks with and without plastics end up ingesting more pathogens.

Diagram illustrating how pathogens can associate with biofilms on microplastics and spread through the sea.
The biofilms that form on microplastics can help pathogens spread through the sea. Emma Zhang, CC BY-NC-ND

A One Health problem

One Health is an approach to research, policy and veterinary and human medicine that emphasizes the close connection of animal, human and environmental health. While it may seem that plastic pollution affects only animals in the ocean, it can ultimately have consequences on human health.

Our project was conducted by a multidisciplinary team of experts, ranging from microplastics researchers and parasitologists to shellfish biologists and epidemiologists. This study highlights the importance of collaboration across human, animal and environmental disciplines to address a challenging problem affecting our shared marine environment.

Our hope is that better understanding how microplastics can move disease-causing pathogens in new ways will encourage others to think twice before reaching for that plastic straw or polyester T-shirt.

Karen Shapiro, Associate Professor of Pathology, Microbiology and Immunology, University of California, Davis and Emma Zhang, Veterinary researcher, University of California, Davis

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Microplastics and pollution combine to become much more toxic: Study

Read the full story in Environmental Health News.

Microplastics can pick up pollution in their travels and pose an even greater threat to human health, according to a new study.

In the ocean, for example, toxic compounds can hitch a ride on plastic and make the material 10 times more toxic than it would normally be, according to the research published earlier this year in Chemosphere.

Although the dangers of both microplastics and harmful compounds have been studied individually, few researchers have look at their combined effect. This study is also unique in that the researchers tested these polluted plastic particles on human cells—most previous research has focused on the impacts on marine life.