Microplastics hit male arteries hard

Changcheng Zhou Professor, Biomedical Sciences
Photo Credit: Courtesy of University of California, Riverside

A mouse study led by University of California, Riverside biomedical scientists suggests that everyday exposure to microplastics — tiny fragments shed from packaging, clothing, and countless plastic products — may accelerate the development of atherosclerosis, the artery-clogging process that leads to heart attacks and strokes. The harmful effects were seen only in male mice, offering new clues about how microplastics may affect cardiovascular health in humans.

“Our findings fit into a broader pattern seen in cardiovascular research, where males and females often respond differently,” said lead researcher Changcheng Zhou, a professor of biomedical sciences in the UCR School of Medicine. “Although the precise mechanism isn’t yet known, factors like sex chromosomes and hormones, particularly the protective effects of estrogen, may play a role.”

What Is: Microplastics

Microplastic
Credit: Scientific Frontline

The Invisible Tide of Plastic

The modern era has been defined, in part, by the versatility and ubiquity of plastic. Yet, this celebrated 20th-century material has given rise to a paradoxical form of pollution—one so pervasive and minute that its scale was largely unrecognized until recently. Microplastics, the synthetic dust of our industrial age, represent a global environmental challenge of unprecedented complexity. These tiny particles, born from the fragmentation of larger debris and the intentional design of microscopic products, have infiltrated every corner of the planet. Scientific expeditions have confirmed their presence from the summit of Mount Everest to the abyssal depths of the Mariana Trench. More alarmingly, this invisible tide has crossed the final frontier, entering the human body itself, with researchers detecting microplastic particles in human blood, lung tissue, and even the placenta.

The ubiquity of microplastics signals a fundamental disruption of planetary systems. They are not merely inert debris but active agents in the environment, interacting with ecosystems and organisms in complex and often detrimental ways. Their journey spans the globe, carried by ocean currents, river systems, and atmospheric winds, connecting the most remote wilderness to the most densely populated urban centers in a shared system of contamination. This report provides a definitive, evidence-based synthesis of the current scientific understanding of microplastics. It aims to dissect the full scope of this issue, beginning with a fundamental definition of the pollutant and a detailed accounting of its myriad sources. It will then trace the environmental fate and transport of these particles through aquatic, terrestrial, and atmospheric systems. Finally, the report will conduct an exhaustive analysis of their multifaceted impacts on ecological integrity and human health, concluding with a critical evaluation of the policies, technologies, and strategies required to mitigate this pervasive threat.

Tracking ocean microplastics from space

Video Credit: University of Michigan

Microplastic pollution can be spotted from space because its traveling companion alters the roughness of the ocean’s surface

New information about an emerging technique that could track microplastics from space has been uncovered by researchers at the University of Michigan. It turns out that satellites are best at spotting soapy or oily residue, and microplastics appear to tag along with that residue.

Microplastics—tiny flecks that can ride ocean currents hundreds or thousands of miles from their point of entry—can harm sea life and marine ecosystems, and they’re extremely difficult to track and clean up. However, a 2021 discovery raised the hope that satellites could offer day-by-day timelines of where microplastics enter the water, how they move and where they tend to collect, for prevention and clean-up efforts.

The team noticed that data recorded by the Cyclone Global Navigation Satellite System (CYGNSS), showed less surface roughness—that is, fewer and smaller waves—in areas of the ocean that contain microplastics, compared to clean areas.

Viruses can ‘hitchhike’ on microplastics

Photo Credit: Naja Bertolt Jensen

Microplastics are not just tiny particles that can be ingested, they can also carry viruses, a University of Queensland study has revealed.

The study, led by Associate Prof Jianhua Guo and Dr Ji Lu from UQ’s Australian Centre for Water and Environmental Biotechnology (ACWEB), investigated if microplastics have the ability to harbor viruses, including the one found inside E. coli bacteria.

“We often hear about the human and environmental harm caused by microplastics in water, but there is little known about whether the tiny microplastic particles can carry viruses,” Dr Guo said.

“What we found is that viruses can hitchhike on microplastics and prolong their infectivity, which means there could be an increased risk of virus transmission throughout waterways and the environment.”

Dr Lu said they used the E. coli bacteriophage in the study, which is a virus that infects and replicates within the bacteria itself and is not harmful to humans.

Microplastics discovered in Antarctica

A view over the Ellsworth Mountains, West Antarctica.
Photo Credit: Steve Gibbs, BAS

Scientists have discovered microplastics in the snow near some of Antarctica’s deep field camps, revealing how far-reaching plastic pollution has become. While not new, it’s the first time these tiny pieces of plastic have been found in remote locations.

The study was conducted at field camps, at Union Glacier and Schanz Glacier (near the Ellsworth Mountains), where researchers were carrying out field work, and the South Pole where the US Antarctic Program has a research station. It is the first time a new and advanced technique has been used to detect microplastics as small as 11 micrometers (about the size of a red blood cell) in the snow in Antarctica. The study is published this week (6 February 2025) in the journal Science of the Total Environment.

The findings surprised the team as microplastics were found at concentrations ranging from 73 to 3,099 particles per liter of snow. Most of these particles (95%) were smaller than 50 micrometers (0.005 cm, the size of most human cells), suggesting previous studies may have underestimated the extent of microplastic pollution in the region due to less sensitive detection methods.

Previous methods involved hand-picking particles and fibers out of samples for laboratory analyses. However, the newer technique involves melting snow through filter paper and scanning this at a high resolution, using infrared spectroscopy, so any plastics above 11 micrometers can be identified.

Microplastic pollution lingers in rivers for years before entering oceans

Study sampling site on the Severn River, downstream from Birmingham, England.

Microplastics can deposit and linger within riverbeds for as long as seven years before washing into the ocean, a new study has found.

Because rivers are in near-constant motion, researchers previously assumed lightweight microplastics quickly flowed through rivers, rarely interacting with riverbed sediments.

Now, researchers led by Northwestern University and the University of Birmingham in England, have found hyporheic exchange — a process in which surface water mixes with water in the riverbed — can trap lightweight microplastics that otherwise might be expected to float.

The study was published in the journal Science Advances. It marks the first assessment of microplastic accumulation and residence times within freshwater systems, from sources of plastic pollution throughout the entire water stream. The new model describes dynamical processes that influence particles, including hyporheic exchange, and focuses on hard-to-measure but abundant microplastics at 100 micrometers in size and smaller.

“Most of what we know about plastics pollution is from the oceans because it’s very visible there,” said Northwestern’s Aaron Packman, one of the study’s senior authors. “Now, we know that small plastic particles, fragments and fibers can be found nearly everywhere. However, we still don’t know what happens to the particles discharged from cities and wastewater. Most of the work thus far has been to document where plastic particles can be found and how much is reaching the ocean.

Microplastics pose a human health risk in more ways than one

Bio-beads collected near Truro.
Photo Credit Beach Guardian

A new study shows that microplastics in the natural environment are colonized by pathogenic and antimicrobial resistant bacteria. The study team calls for urgent action for waste management and strongly recommends wearing gloves when taking part in beach cleans. 

Microplastics are plastic particles less than 5mm in size and are extremely widespread pollutants. It is estimated that over 125 trillion particles have accumulated in the ocean (surface to seabed) and they have also been detected in soils, rivers, lakes, animals and the human body. 

An emerging concern associated with microplastics is the microbial communities that rapidly make their home on the particle surface, forming complex biofilms known as the “Plastisphere”. These communities may often include pathogenic (disease-causing) or antimicrobial resistant (AMR) bacteria. 

SoMAS Study: Microplastics in Oceans Distort Carbon Cycle Understanding

Plastic items, such as this part of a swimming float (blue), are often seen at ocean shorelines. These products eventually break down into microplastics, which permeate the oceans and add to the distribution of carbon along with organic matter.
Photo Credit: Luis Medina.

A study by researchers in Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS) shows that when microplastics are accidentally collected and measured with natural ocean organic particles, the carbon released by plastics during combustion appears as if it came from natural organic matter, which distorts scientists’ understanding of the ocean’s carbon cycle.

The carbon cycle in our oceans is critical to the balance of life in ocean waters and for reducing carbon in the atmosphere, a significant process to curbing climate change or global warming.

Microplastics are everywhere in the oceans. These small plastic fragments come from the breakdown of larger plastic items polluting the seas. Once they reach the sea through rivers, wastewater or runoff, they spread through coastal and open-ocean waters.

Tiny plastic particles are found everywhere

The researchers were out in the southern Arctic Ocean on the research vessel Polarstern and took water samples, which they analyzed for the smallest microplastic particles.
Photo Credit: Clara Leistenschneider, University of Basel

Microplastic particles can be found in the most remote ocean regions on earth. In Antarctica, pollution levels are even higher than previously assumed. This is one finding of a recent study involving researchers from the University of Basel.

It’s not the first study on microplastics in Antarctica that researchers from the University of Basel and the Alfred-Wegener Institute (AWI) have conducted. But analysis of the data from an expedition in spring 2021 shows that environmental pollution from these tiny plastic particles is a bigger problem in the remote Weddell Sea than was previously known.

The total of 17 seawater samples all indicated higher concentrations of microplastics than in previous studies. “The reason for this is the type of sampling we conducted,” says Clara Leistenschneider, doctoral candidate in the Department of Environmental Sciences at the University of Basel and lead author of the study.

The current study focused on particles measuring between 11 and 500 micrometers in size. The researchers collected them by pumping water into tanks, filtering it, and then analyzing it using infrared spectroscopy. Previous studies in the region had mostly collected microplastic particles out of the ocean using fine nets with a mesh size of around 300 micrometers. Smaller particles would simply pass through these plankton nets.

The results of the new study indicate that 98.3 percent of the plastic particles present in the water were smaller than 300 micrometers, meaning that they were not collected in previous samples. “Pollution in the Antarctic Ocean goes far beyond what was reported in past studies,” Leistenschneider notes. The study appears in the journal Science of the Total Environment.

Synthetic fibers discovered in Antarctic samples show the ‘pristine’ continent is now a sink for plastic pollution

As nations prepare to meet in Uruguay to negotiate a new Global Plastics Treaty, a new study has revealed the discovery of synthetic plastic fibers in air, seawater, sediment and sea ice sampled in the Antarctic Weddell Sea. The field research was carried out by scientists from the University of Oxford and Nekton (a not-for-profit research institute) during an expedition to discover Sir Ernest Shackleton’s ship, the Endurance. The results are published in the journal Frontiers in Marine Science.

Fibrous polyesters, primarily from textiles, were found in all samples. The majority of microplastic fibers identified were found in the Antarctic air samples, revealing that Antarctic animals and seabirds could be breathing them.

‘The issue of microplastic fibers is also an airborne problem reaching even the last remaining pristine environments on our planet’, stated co-author Lucy Woodall, a Professor in the University of Oxford’s Department of Biology and Principal Scientist at Nekton. ‘Synthetic fibers are the most prevalent form of microplastic pollution globally and tackling this issue must be at the heart of the Plastic Treaty negotiations.’ Professor Woodall was the first to reveal the prevalence of plastic in the deep sea in 2014.

Microplastics in the atmosphere: higher emissions from land areas than from the ocean

Image Credit: Scientific Frontline / AI generated

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Terrestrial sources emit over 20 times more microplastic particles into the atmosphere than oceanic sources, challenging previous assumptions that the ocean was the primary emitter.
• Methodology: Researchers collected 2,782 globally distributed atmospheric microplastic measurements and compared them against a transport model using three different emission estimates, subsequently rescaling the emission data to reconcile significant discrepancies between the model and observations.
• Key Data: While land areas emit >20 times more individual particles, the total emitted mass is actually higher over the ocean due to the significantly larger average size of oceanic particles.
• Significance: This study provides the first rescaled, observation-based estimate of global microplastic emissions, revealing that current models had overestimated atmospheric microplastic concentrations and deposition rates by several orders of magnitude.
• Future Application: These improved emission estimates will refine global pollution transport models and help isolate specific contributions from sources like road traffic (tyre abrasion) versus other land-based activities.
• Branch of Science: Meteorology and Geophysics.
• Additional Detail: Primary terrestrial sources were identified as tyre abrasion, textile fibers, and the resuspension of already contaminated dust and soil.

Scientists uncover evidence that microplastics are contaminating archaeological remains

The study identified 16 different microplastic polymer types across both contemporary and archived samples.
PHoto Credit: York Archaeology

Researchers have for the first-time discovered evidence of microplastic contamination in archaeological soil samples.

The study identified 16 different microplastic polymer types across both contemporary and archived samples. Pic credit: York Archaeology

The team discovered tiny microplastic particles in deposits located more than seven meters deep, in samples dating back to the first or early second century and excavated in the late 1980s.

Tiny particles

Preserving archaeology in situ has been the preferred approach to managing historical sites for a generation. However, the research team say the findings could prompt a rethink, with the tiny particles potentially compromising the preserved remains.

Microplastics are small plastic particles, ranging from 1μm (one thousandth of a millimeter) to 5mm. They come from a wide range of sources, from larger plastic pieces that have broken apart, or resin pellets used in plastic manufacturing which were frequently used in beauty products up until around 2020.

Microplastics limit energy production in tiny freshwater species

Paramecium bursaria
Image Credit: Picturepest
(CC BY 2.0)

Microplastic pollution reduces energy production in a microscopic creature found in freshwater worldwide, new research shows.

Paramecium bursaria contain algae that live inside their cells and provide energy by photosynthesis.

A new study, by the University of Exeter, tested whether severe microplastic contamination in the water affected this symbiotic relationship.  

The results showed a 50% decline in net photosynthesis – a major impact on the algae’s ability to produce energy and release oxygen.

“The relationship I examined – known as photosymbiosis – is commonly found both in freshwater and the oceans,” said Dr Ben Makin, lead author and associate researcher at the Environment and Sustainability Institute on Exeter’s Penryn Campus in Cornwall.

“We know climate change can damage photosymbiotic relationships, including in corals (leading to ‘bleaching’ events).

How much microplastic do whales eat? Up to 10 million pieces per day

Humpback whales lunge feed in Monterey Bay. New research shows whales are ingesting plastic in larger quantities than previously thought, and nearly all comes from their prey, not from the enormous volumes of seawater the whales gulp when feeding.
Photo Credit: shadowfaxone

Analysis of ocean plastic pollution and whale foraging behavior tracked with noninvasive tags shows whales are ingesting tiny specks of plastic in far bigger quantities than previously thought, and nearly all of it comes from the animals they eat – not the water they gulp.

The largest animals ever known to have lived on Earth ingest the tiniest specks of plastic in colossal amounts, Stanford University scientists have found.

Published in Nature Communications, the study focuses on blue, fin, and humpback whales and their consumption of plastic fragments no bigger than a few grains of sand, which are commonly called microplastics. The authors combined measures of microplastic concentrations up and down the water column off the coast of California with detailed logs of where hundreds of whales carrying tracking devices foraged for food between 2010 and 2019.

They found the whales predominantly feed 50 to 250 meters below the surface, a depth that coincides with the highest concentrations of microplastic in the open ocean. The planet’s biggest creature – the blue whale – ingests the most plastic, at an estimated 10 million pieces per day as it feeds almost exclusively on shrimplike animals called krill.

“They’re lower on the food chain than you might expect by their massive size, which puts them closer to where the plastic is in the water. There’s only one link: The krill eats the plastic, and then the whale eats the krill,” said study co-author Matthew Savoca, a postdoctoral scholar at Hopkins Marine Station, Stanford’s marine laboratory on the Monterey Peninsula.

Some bottled water worse than tap for microplastics

Underestimating microplastic concentrations in drinking water can raise the potential for human health risks.
Photo Credit: Serenity Mitchell

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Certain brands of bottled water contain significantly higher concentrations of microplastics and nanoplastics compared to treated tap water.
• Methodology: Researchers analyzed water samples from four Lake Erie-area treatment plants and six bottled water brands using a novel combination of scanning electron microscopy for imaging and optical photothermal infrared spectroscopy for chemical identification.
• Key Data: Bottled water samples contained three times as many nanoplastic particles as the treated drinking water, with over 50% of all detected particles classified as nanoplastics.
• Significance: These findings indicate that prior studies likely underestimated the scope of plastic contamination by overlooking nanoplastics and suggest that consuming tap water may reduce daily exposure to synthetic particles.
• Future Application: The analytical techniques developed in this study can be applied to evaluate the efficiency of water treatment processes in removing nanoplastics and to guide future remediation designs.
• Branch of Science: Environmental Science and Engineering
• Additional Detail: The primary source of plastic particles in the bottled water was confirmed to be the packaging itself, whereas the specific origins of the contamination in tap water remain unclear.

New study finds that microplastics can help dangerous bacteria survive on beaches

Microplastics on the beach
Photo Credit: Vera Kratochvil

New research from the University of Stirling has found that dangerous bacteria are able to survive the journey from sewage treatment plants to beaches on microplastic pollution.

During their study, scientists from the University’s Faculty of Natural Sciences found drug-resistant bacteria colonizing microplastics on Scottish beaches.  

The findings could have global consequences, with an estimated 2.3 million tons of plastic pollution thought to be floating in the world’s oceans.

Lead researcher Rebecca Metcalf, supervised by Professor Richard Quilliam, conducted her research by subjecting microplastics colonized by bacteria in wastewater to the different environments that they would likely pass through on their way to our beaches. She found that not only could the bacteria such as E. coli survive the entire journey, but that viable bacteria also survived for seven days on the sand. 

There are large accumulations of plastics in the ocean, even outside so-called garbage patch

Neuston net towed on the side of the German RV SONNE, collecting surface-floating plastic samples when crossing the North Pacific Ocean.
Photo Credit: Philipp Klöckner / UFZ

When plastic ends up in the ocean, it gradually weathers and disintegrates into small particles. If marine animals ingest these particles, their health can be severely affected. Large accumulations of plastic can therefore disrupt the biological balance of marine ecosystems. But which areas are particularly affected? In a recent study, a research team from the Helmholtz Centre for Environmental Research (UFZ), in collaboration with the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), has found large quantities of plastic waste and microplastics in a remote marine protected area in the Pacific Ocean. These quantities were similar to those found in one of the world’s largest known garbage patches. The researchers highlight that plastics are distributed much more widely than expected. The entire ocean ecosystem is threatened. They therefore call for the global emissions of plastics into the ocean to be stopped as quickly as possible. The study has been published in Environmental Science & Technology.

Thousands of tons of microplastics found in Moreton Bay

Dr Elvis Okoffo has tested samples of mud from Moreton Bay for microplastics.
Photo Credit: Courtesy of University of Queensland

University of Queensland researchers estimate there could be up to 7000 tons of microplastics polluting vital ecosystems in Brisbane’s Moreton Bay.

Dr Elvis Okoffo from UQ’s Queensland Alliance for Environmental Health Sciences said the team measured plastic stored within 50 surface sediment samples collected across Moreton Bay.

“The level of plastic contamination we found is equivalent to three Olympic swimming pools full of plastic or 1.5 million single use plastic bags,” Dr Okoffo said.

“The main types of plastic detected were polyethylene (PE) and polyvinyl chloride (PVC).

“PE is used for single-use items such as plastic food wrapping, bags and bottles and PVC is used in pipes, building materials, electronics, and clothing.

Plastic particles increase inflammation and cross barriers

Lukas Kenner, visiting professor, Department of Molecular Biology.
Photo Credit: Medizinische Universität Wien

Scientific Frontline: "At a Glance" Summary

• Core Discovery: Micro- and nanoplastics (MNPs) exacerbate chronic inflammatory bowel diseases (IBD) and penetrate biological barriers to accumulate in vital organs beyond the gastrointestinal tract.
• Methodology: Researchers utilized a mouse model of ulcerative colitis, orally administering polystyrene particles—a common plastic found in food packaging—to analyze molecular and histological interactions with the intestinal mucosa and immune system.
• Mechanism of Action: MNP exposure triggers pro-inflammatory activation of macrophages and induces gut dysbiosis, characterized by a decrease in beneficial bacterial species and an increase in potentially harmful, pro-inflammatory microbes.
• Data Point: Nanoplastic particles smaller than 0.0003 millimeters (0.3 micrometers) demonstrated the highest mobility, successfully traversing the intestinal barrier to deposit in the liver, kidneys, and bloodstream.
• Contextual Findings: The uptake of MNPs into the intestinal mucosa is significantly intensified during active inflammatory states, suggesting a feedback loop where existing inflammation facilitates further plastic accumulation.
• Primary Implication: MNPs are an underestimated environmental factor in the pathogenesis of chronic inflammatory diseases, highlighting an urgent need to evaluate the systemic health risks posed by the migration of the smallest particles into major organ systems.

Monitoring the "journey" of microplastics through the intestine of a living organism

Drosophila melanogaster 
Credit: Universitat Autònoma de Barcelona

A UAB research team has managed to track the behavior of microplastics during their "journey" through the intestinal tract of a living organism and illustrate what happens along the way. The study, carried out on Drosophila melanogaster using electron microscopy equipment developed by the researchers themselves, represents a significant step towards a more precise analysis of the health risks of being exposed to these pollutants.

The behavior of micro and nanoplastics (MNPLs) inside the organism is a question impossible to answer at present in humans, and in vitro models are not useful. Hence, there is a need to look for models that allow us to answer this question. Furthermore, there are limitations in the current methodologies for detecting and quantifying their presence in different human biological samples, which prevents an accurate assessment of the health risk of exposure.

In this context, researchers from the Mutagenesis Research Group of the Universitat Autònoma de Barcelona (UAB) have managed to monitor the tracking of MNPLs in their "journey" from the environment to the interior of a living organism. They have done it by developing tools based on electron microscopy and in larvae of the Drosophila melanogaster fly, a model organism widely used to study biological phenomena and processes.