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Facemask pollution

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During the height of the Covid-19 pandemic, the global usage of disposable facemasks reached a staggering 129 billion per month. Most of these masks are manufactured from petroleum-based non-renewable plastics like polypropylene and the disposal of these masks results in serious pollution problems.  These include the loss of ecological integrity from buried waste in landfills, air pollution from increased waste incineration, and microplastic pollution. 

Recent research by engineers at Washington University in St. Louis investigated the multipronged pollution problem brought about by discarded facemasks.  The study in particular looked at the chemical changes that occur when facemasks are exposed to sunlight, water, and trace metal ions.

Masks littering the environment degrade into nanoplastics and produce reactive oxygen species.  These chemical agents interact with trace metal ions in the environment within hours.  The result is oxides of metals like manganese and iron, which can drive various biogeochemical reactions.

Abandoning and forgetting about plastics like facemasks is an unsustainable practice.  Plastics not only cause physical damage, but also introduce unpredictable and potentially dangerous chemical changes into environmental systems.

Plastic waste is a global problem that has continued to grow and become an increasingly serious threat over decades.  Understanding the nature of the effects of billions of facemasks in the environment is essential to efforts to address the challenges created by them.

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Sun exposure changes chemical fate of littered face masks

Photo, posted August 21, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Microplastics in Antarctica

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Microplastics are small plastic pieces less than five millimeters long and typically far smaller than that.  They come from a variety of sources, often from larger plastic debris that degrades into smaller and smaller pieces.  There are also microbeads, which are tiny pieces of manufactured polyethylene plastic that are added to various health and beauty products.  Tiny bits of plastic easily pass through filtration systems and end up in the ocean and other bodies of water.

Microplastics are a pervasive problem for which nowhere on Earth is truly untouched.  Despite stringent regulations on materials entering Antarctica, scientists have discovered microplastics in the snow near some of the deep field camps there.

A study by the British Antarctic Survey made use of a new and advanced technique that can detect microplastics as small as 11 microns – about the size of a red blood cell.

The research team found microplastics at concentrations ranging from 73 to 3,099 particles per liter of snow. 

Snow samples from three different sites identified polyamide (used in textiles), polyethylene terephthalate (found in bottles and packaging), polyethylene, and synthetic rubber.  The results suggest that at least the polyamide, which accounted for half the microplastics found, came from local sources.

Additional research is needed to fully understand the sources of microplastic pollution in Antarctica and to understand the broader implications of microplastics in that frozen wilderness. Microplastics have already been detected in several penguin, seal, and fish species.

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Microplastics discovered in Antarctica

Photo, posted February 3, 2015, courtesy of Christian Stangl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Native plants and road salt pollution

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Applying salt to roadways lowers the freezing point of water and prevents slippery surfaces, which makes it safer for people to drive in wintry conditions.  In the U.S., more than 22 million tons of road salt is spread every year. 

But road salt harms infrastructure and the environment.   In fact, road salt damages cars and metal infrastructure by accelerating rust and corrosion.  Road salt can also leach into soil and waterways, disrupting ecosystems, degrading soil, contaminating water, and damaging vegetation. 

In cities and towns, road salts often wash into stormwater systems, posing health concerns and challenges for infrastructure.

A new study led by researchers from Virginia Tech looked at how salt affects plants and whether certain plants could mitigate salt pollution. The research team studied stormwater detention basins in Northern Virginia, examining the impacts of road salt on plants, soils, and water quality in green infrastructure systems.

The findings, which were recently published in the journal Science of the Total Environment, found that the amount of salt present in green infrastructure systems does reach levels that threaten plant communities.  However, the researchers found that relying on salt-tolerant plants for mitigation is unlikely to be effective because they simply don’t take in enough salt.

Certain plants, particularly cattails, absorbed substantial amounts of salt.  But even in a basin densely planted with salt-tolerant cattails, only up to 6% of the road salt applied during winter could be removed. 

Plants alone cannot solve our salt pollution problem.

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Researcher studies the power of native plants to combat road salt pollution

Photo, posted January 22, 2025, courtesy of the City of Greenville, North Carolina via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Barley plastic

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The durability, malleability, and low cost of plastics have made them ubiquitous.  Plastics are everywhere:  in packaging, clothing, and an endless variety of products.  As a result, they are everywhere in the environment and they tend to stay there, contaminating land and sea.  They are tough to recycle, and their production emits more carbon dioxide than all air traffic combined.  The search for viable substitutes for plastic is global and intensive.

Most common bioplastics are not an ideal solution.  They don’t break down that easily when tossed into the natural environment.  The process can take years. 

Researchers at the University of Copenhagen have invented a new material made from modified starch that can completely decompose in nature and can do so in only two months.  The material is made using natural plant material from crops and could be used for food packaging as well as many other things.

The new material is a biocomposite composed of several substances that decompose naturally.  The main ingredients are amylose and cellulose, common in many plants.  Amylose is extracted from crops like corn, potatoes, wheat, and barley.

The Danish researchers have developed a barley variety that produces pure amylose in its kernels.  Pure amylose is ideal because it is less likely to turn into a paste when it interacts with water. 

Combining the amylose with cellulose forms long, strong molecular chains, resulting in a durable, flexible material that can replace plastic in many applications.  The research team has founded a spinoff company and have applied for a patent for the new material.  It is unclear when the biofriendly barley-based plastic might be commercialized, but its potential is quite good.

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Researchers invent one hundred percent biodegradable “barley plastic”

Photo, posted May 20, 2010, courtesy of Frederick Lang Jr. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Biodegradable microplastics

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Ordinary plastics are not biodegradable, but they are also not indestructible.  Plastics in the environment can break down into tiny fragments – microplastics – and those, unfortunately, are nearly indestructible.  Microplastics have been documented in the oceans and in soil virtually everywhere on Earth including remote frozen wastelands and on top of high mountains.  More recently, they have been found in our own arteries, lungs, and even in placentas.  Microplastic pollution is a very serious problem.

There is considerable ongoing effort to develop biodegradable plastics from non-petroleum sources.  There has been progress but it has not necessarily been aimed at creating bioplastics that do not create microplastic when they break down.

Researchers at the University of California San Diego have developed algae-based polymers that they have shown to degrade when composted.  Recently, in work published in the journal Nature Scientific Reports, they have shown that even fine microparticles of their bioplastic are digested by microbes when placed in a compost.  What remains are the starting plant materials from which the plastic was made.  Products made from this sort of plastic would not only be sustainable beyond their useful lifetime but would also not represent a potential danger to human life.

Creating this eco-friendly alternative to petroleum-based plastic is only the first step toward creating a viable replacement for existing plastics.  It is necessary to be able to use the new material on existing manufacturing equipment and for it to have the same mechanical and thermal properties as the materials it is replacing.  But the researchers are optimistic that this could be a potential solution to an increasingly serious problem.

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Say Hello to Biodegradable Microplastics

Photo, posted January 17, 2018, courtesy of Bo Eide via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic-Eating Bugs | Earth Wise

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27-year-old Miley Cyrus and 30-year-old Liam Hemsworth divorced exactly one year ago, but still continue to remember each other quite often in conversations with reporters. Recently, Miley indulged in nostalgia once again. During a recording Miley Cyrus boyfriend list of the podcast Barstool Call Her Daddy, the singer said that her ex-husband was her first man. It happened almost 10 years before they got married. I didn’t have that with men until I was 16, but I ended up marrying this guy,

According to a new study, microbes in oceans and soils around the world are evolving to eat plastic.  The study by Chalmers University in Sweden was published recently in the journal Microbial Ecology.

The study is the first large-scale assessment of the plastic-degrading potential of bacteria.  There are 95 microbial enzymes already known to degrade plastic. 

The researchers looked for similar enzymes in environmental DNA samples taken from bacteria from 236 different locations around the world. They found that one in four of the organisms analyzed carried suitable enzymes.  Overall, they found many thousands of new enzymes.

The explosion of plastic production in the past 70 years has given microbes time to evolve to make use of plastic.  About 12,000 new enzymes were found in ocean samples and 18,000 in soil samples.  Nearly 60% of the new enzymes did not fit into any known enzyme classes, suggesting that these molecules degrade plastics in ways that were previously unknown.  The large number of enzymes in such a wide range of habitats is an indication of the scale of the problem of plastics in the environment.

The first bacterium that eats plastic was discovered in a Japanese waste dump in 2016.  Scientists tweaked that microbe in 2018 and managed to create an enzyme that was even better at breaking down plastic bottles.

The next step in research is to test the most promising enzyme candidates in the laboratory to investigate their properties and see how effective they can be in plastic degradation.  The hope is to be able to engineer microbial communities with targeted degrading functions for specific polymer types.

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Bugs across globe are evolving to eat plastic, study finds

Photo, posted June 19, 2013, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Wood Into Plastic | Earth Wise

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Plastic pollution is particularly pernicious because plastics can take hundreds of years to degrade in the environment.  For this reason, researchers across the globe search for ways to shift from petrochemical plastics to ones that are biodegradable.

Producing biodegradable plastics is challenging both from the standpoint of the methods needed and from the results obtained.  Producing them often requires toxic chemicals and can be very expensive.  The materials that emerge often do not have the durability and strength of conventional plastics and can be unstable when exposed to moisture.

Researchers at the Yale School of the Environment have developed a process of decomposing the porous matrix of natural wood into a slurry that can be formed into a biodegradable plastic.  The material shows high mechanical strength, stability when holding liquids, and is resistant to the effects of ultraviolet light.  Along with all these favorable properties, the material can be recycled or safely biodegraded in the natural environment.

The slurry mixture is created by taking wood powder – a processing residue usually discarded in lumber mills – and deconstructing it with a biodegradable and recyclable solvent.  The resulting mixture has a high solid content and high viscosity and can be casted and rolled without breaking.

The researchers conducted a comprehensive life cycle assessment to test the environmental impacts of the bioplastic compared with conventional plastics.  Sheets of it were buried in soil and observed to fracture after two weeks and completely degrade after three months.  The material can also be broken back down into the slurry by mechanical stirring.

The remaining topic to investigate is the potential impact on forests if the manufacturing of this bioplastic is scaled up.

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Turning wood into plastic

Photo, posted October 12, 2016, courtesy of the US Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Superstrong Nanofibers | Earth Wise

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Self-assembly is a ubiquitous process in the natural world that leads to the formation of the DNA double helix, the creation of cell membranes, and to many other structures.   Scientists and engineers have been working to design new molecules that assemble themselves in water for the purpose of making nanostructures for biomedical applications such as drug delivery or tissue engineering.  For the most part, the materials created in this way have been chemically unstable and tended to degrade rapidly, especially when the water is removed.

A team at MIT recently published a paper describing a new class of small molecules they have designed that spontaneously assemble into nanoribbons with unprecedented strength and that retain their structure outside of water.

The material is modeled after a cell membrane.  Its outer part is hydrophilic (it likes to be in water) and its inner part is hydrophobic (it tries to avoid water.)  This configuration drives the self-assembly to create a specific nanostructure and by choosing the appropriate chemicals to form the structures, the result was nanoribbons in the form of long threads that could be dried and handled.  The resultant material in many ways resembles Kevlar.   In particular, the threads could hold 200 times their own weight and have extraordinarily high surface areas.  The fibers are stronger than steel and the high surface-to-mass ratio offers promise for miniaturizing technologies for such applications as pulling heavy-metal contaminants out of water and for use in electronic devices and batteries.

The goal of the research is to tune the internal state of matter to create exceptionally strong molecular nanostructures.  The potential for important new applications is considerable and exciting.

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Researchers construct molecular nanofibers that are stronger than steel

Photo, posted June 19, 2007, courtesy of Andrew Hitchcock via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sustainable Flip-Flops | Earth Wise

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Flip-flops are the world’s most popular shoe.  They are lightweight, comfortable, affordable, and durable.  In fact, the global market for flip-flops is expected to reach a whopping $23.8 billion by the year 2025. 

But the popularity comes with a price.  Flip-flops account for a troubling percentage of plastic waste that ends up in our landfills and oceans.  As a result, demand for alternatives is compelling researchers to develop more sustainable versions of the popular footwear.

Scientists at the University of California San Diego have spent years working on this issue, and recently announced a breakthrough.  According to a study recently published in Bioresource Technology Reports, the research team has formulated polyurethane foams – made from algae oil – to meet commercial specifications for mid-sole shoes and the foot-bed of flip-flops.   In other words, the scientists have created sustainable, biodegradable, and consumer-ready materials that could replace plastics in some footwear. 

The UC San Diego scientists collaborated with Algenesis Materials – a technology startup – on the research.  Together, they worked to not only create the shoes, but to degrade them as well.  The team tested their customized foams by immersing them in traditional compost and soil.  The algae-based materials degraded after just 16 weeks.  

The life of any material should be proportionate to the life of the product.  The researchers point out that it doesn’t make sense to create a product that will last 500 years if it’ll only be used for a year or two. 

The research team is currently working on production details with its manufacturing partners.  The creation of biodegradable flip-flops that meet commercial footwear standards could eliminate tons of plastic waste from the environment.   

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New science behind algae-based flip-flops

Flip Flops Market Size Worth $23.8 Billion by 2025

Photo, posted December 12, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Trash Into Treasure

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Every year, 380 million tons of plastic are created worldwide, and that number continues to grow.  Furthermore, more than 75% of these materials are discarded after one use.  Much of it ends up in oceans and waterways, harming wildlife and spreading toxins.

Recycling most plastics is difficult because while they can be melted and reprocessed, the resultant material is not as structurally strong as the original material.  Thus, plastics are often down-cycled such as turning plastic bottles into molded park benches.

Researchers at Northwestern University, Argonne National Laboratory, and Ames Laboratory have developed a new method for upcycling abundant, seemingly low-value plastics into high-quality liquid products, such as motor oils, lubricants, detergents, and even cosmetics.  The catalytic method  could remove plastic pollution from the environment and contribute to a circular economy.

Plastics don’t degrade when disposed of because they have very strong carbon-carbon bonds.  Instead they just break into smaller bits, known as microplastics.  The researchers viewed these strong bonds as an opportunity rather than a problem.

The new technique actually recoups the high energy that holds these bonds together by catalytically converting polyethylene molecules into value-added commercial products.  The catalyst consists of platinum nanoparticles deposited onto perovskite nanocubes.  Under moderate pressure and temperature, the catalyst cleaves the carbon-carbon bonds in plastic to produce high-quality liquid hydrocarbons. 

The researchers believe these findings could lead to a future in which we can continue to benefit from plastic materials but do so in a way that is sustainable and less harmful to the environment.

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Turning plastic trash into treasure

Photo, posted August 15, 2012, courtesy of Emilian Robert Vicol via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protection From Toxic Algae

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Toxic algal blooms have been a growing problem in recent years associated with warming waters and nutrient-rich agricultural runoff in lakes, rivers, and oceans.  In 2014, an algal bloom in Lake Erie left half a million residents of Toledo, Ohio without safe drinking water for three days.

The most common toxic substance released by algal blooms in the lake is called microcystin, which is closely linked to liver cancer and other diseases.  Toxicologists measure microcystin and other contaminants using the metric of parts per billion.  The EPA recommends that young children not drink water containing more than 0.3 parts per billion and adults no more than 1.6 parts per billion of microcystin.

Scientists at the University of Toledo have been working on developing a biofilter that uses naturally occurring Lake Erie bacteria to remove microcystin released by algal blooms and thereby reduce or eliminate the use of chlorine and other chemicals.

They have successfully isolated a number of types of bacteria that degrade microcystin toxin at a daily rate of up to 19 parts per billion.  To their knowledge, such bacteria have not been previously used to fight algal blooms in other parts of the world.  Based on the recorded toxin levels in Lake Erie in recent years, the bacteria would be able to effectively remove microcystin from water supplies.  None of the 13 bacterial isolates they found have any association with human disease so their use in future water-purifying biofilters should not pose a public health concern.

The researchers are now developing and testing biofilters, which are water filters containing the specialized bacteria that will degrade the toxins from lake water as it flows through the filter.

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Scientists advance new technology to protect drinking water from Lake Erie algal toxins

Photo, posted April 30, 2014, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pesticides And Food Insecurity

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A newly released report by the United Nations takes a strong stance against the use of industrial agrochemicals, saying that they are not necessary for feeding the world.  The continued use of pesticides at the rate the world currently does in fact can have very detrimental consequences.

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