Tag: health

Plastic-eating bacteria discovered in the ocean

Source:King Abdullah University of Science & Technology (KAUST)

Summary:Beneath the ocean’s surface, bacteria have evolved specialized enzymes that can digest PET plastic, the material used in bottles and clothes. Researchers at KAUST discovered that a unique molecular signature distinguishes enzymes capable of efficiently breaking down plastic. Found in nearly 80% of ocean samples, these PETase variants show nature’s growing adaptation to human pollution.Share:

    

FULL STORY

Plastic-Eating Bacteria Discovered in the Ocean
Bacteria armed with the M5 motif on their PETase enzyme can feast on plastic, a trait now seen thriving across the world’s oceans. Credit: © 2025 KAUST

Far beneath the ocean’s surface, researchers have found bacteria that can digest plastic, using specialized enzymes that evolved alongside humanity’s synthetic debris.

A large-scale global study by scientists at KAUST (King Abdullah University of Science and Technology) revealed that these marine microbes are widespread and genetically prepared to consume polyethylene terephthalate (PET) — the tough plastic used in everyday items like drink bottles and fabrics.

Their remarkable ability stems from a distinct structural feature on a plastic-degrading enzyme called PETase. This feature, known as the M5 motif, acts as a molecular signature that signals when an enzyme can truly break down PET.

“The M5 motif acts like a fingerprint that tells us when a PETase is likely to be functional, able to break down PET plastic,” explains Carlos Duarte, a marine ecologist and co-leader of the study. “Its discovery helps us understand how these enzymes evolved from other hydrocarbon-degrading enzymes,” he says. “In the ocean, where carbon is scarce, microbes seem to have fine-tuned these enzymes to make use of this new, human-made carbon source: plastic.”

How Nature’s Recyclers Evolved

For decades, scientists believed PET was almost impossible to degrade naturally. That belief began to shift in 2016, when a bacterium discovered in a Japanese recycling plant was found to survive by consuming plastic waste. It had developed a PETase enzyme capable of dismantling plastic polymers into their building blocks.

Yet it remained unclear whether oceanic microbes had developed similar enzymes independently.

Using a combination of artificial intelligence modeling, genetic screening, and laboratory testing, Duarte and his team confirmed that the M5 motif distinguishes true PET-degrading enzymes from inactive look-alikes. In experiments, marine bacteria carrying the complete M5 motif efficiently broke down PET samples. Genetic activity maps showed that M5-PETase genes are highly active throughout the oceans, especially in areas heavily polluted with plastic.

Global Spread of Plastic-Eating Microbes

To understand how widespread these enzymes are, the researchers examined more than 400 ocean samples collected from across the globe. Functional PETases containing the M5 motif appeared in nearly 80 percent of the tested waters, ranging from surface gyres filled with floating debris to nutrient-poor depths nearly two kilometers below.

In the deep sea, this ability may give microbes an important edge. The ability to snack on synthetic carbon may confer a crucial survival advantage, noted Intikhab Alam, a senior bioinformatics researcher and co-leader of the study.

The discovery highlights a growing evolutionary response: microorganisms are adapting to human pollution on a planetary scale.

Although this adaptation reveals nature’s resilience, Duarte cautions against optimism. “By the time plastics reach the deep sea, the risks to marine life and human consumers have already been inflicted,” he warns. The microbial breakdown process is far too slow to offset the massive flow of plastic waste entering the oceans each year.

Turning Discovery Into Real-World Solutions

On land, however, the findings could accelerate progress toward sustainable recycling. “The range of PET-degrading enzymes spontaneously evolved in the deep sea provides models to be optimized in the lab for use in efficiently degrading plastics in treatment plants and, eventually, at home,” says Duarte.

The identification of the M5 motif offers a roadmap for engineering faster, more effective enzymes. It reveals the structural traits that work under real environmental conditions rather than just in test tubes. If scientists can replicate and enhance these natural mechanisms, humanity’s battle against plastic pollution may find powerful new allies in one of the planet’s most unexpected places: the deep ocean.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2025/11/251104013023.htm

The Polluted Tijuana River Is Polluting the Air in San Diego

Some people who reside in the southern portion of San Diego County, California, say it stinks to live there. Literally. For years, residents have complained that odors emanating from the polluted Tijuana River, which flows from Mexico into the U.S. toward the Pacific Ocean, are causing eye, nose and throat irritation, respiratory problems, fatigue, and headaches.

A new study shows that turbulence in polluted waters of the Tijuana River transfers contaminants to the air. In this photo, culverts at the Saturn Boulevard river crossing generate high turbulence, enhancing the transfer of toxic wastewater pollutants. The location was identified by members of the local community as a source of particularly strong odors.  |  Credit: Beatriz Klimeck / UC San Diego

Now, a new study from scientists at UC, San Diego Scripps Institution of Oceanography; UC, Riverside; San Diego State University; the National Science Foundation; and National Center for Atmospheric Research (NCAR) says the residents are not imagining things. The research found that the contaminated river is contaminating the air—releasing large quantities of the toxic gas hydrogen sulfide—commonly known as “sewer gas” because of its rotten egg smell.

In September 2024, the team had set up air quality monitors in San Diego’s Nestor community in the South Bay. One location was where water tumbles from a culvert, which as it falls, creates enough turbulence to send aerosolized particles of pollutants from the river into the air.

The scientists measured peak concentrations of hydrogen sulfide that were some 4,500 times what is typical for an urban area. In addition, they identified hundreds of other gases released into the air by the river and its ocean outflow, showing for the first time, a direct link between poor water quality and bad air quality—a connection lead investigator Kimberly Prather says had not been made before.

Untreated sewage and industrial waste have plagued the Tijuana River for decades, causing long-term closures of beaches. In July, the U.S. and Mexico signed a memorandum of understanding that requires both nations to expedite stormwater and sewage infrastructure projects on each side of the border.  

Last week, EPA announced the completion of a ten-million-gallon-per-day expansion of the South Bay International Wastewater Treatment Plant in San Diego, which could help mitigate the issue, but as inewsource reports, it’s unclear as to when it will be operating at its new capacity.

The paper was published in the journal Science.

CLICK HERE FOR MORE INFORMATION

https://h2oradio.org

Investigators

Portable tests could detect “forever chemicals” in your home’s drinking water

By Tara Molina

We know how important clean water is, but tricky chemicals that get into our water can be hard to detect, posing dangers to our water systems and our health ­– until now.

Researchers with the University of Chicago have teamed up with Argonne National Labs in Lemont to detect the smallest chemicals in our water in an effort to make it safer and healthier for all.

PFAS, or per- and polyfluoroalkyl substances, are better known as “forever chemicals.” They’re man-made compounds that are found in places like fast food packaging, firefighters’ foams and other places. They’re long-lasting chemicals and do not naturally degrade, instead accumulating in the environment and our bodies over time, which is why the Environmental Protection Agency issued regulations on them last year.

Until recently, they were somewhat difficult to detect in drinking water, but labs like Argonne are making gains.

“It affects essentially all of us, and it is, in fact, dangerous,” Argonne’s Seth Darling said. “They’re really toxic to humans. They’ve been linked to cancer, they’ve been linked to reproductive issues, thyroid problems, all kinds of health issues.”

Darling is working alongside Junhong Chen, with UChicago’s Pritzker School of Molecular Engineering. They’re building a first-of-its-kind sensor that can detect PFAS in water.

“The work we are doing here is really important, because now we have a way to be able to measure this PFAS,” Chen said. “Almost the only way to measure for PFAS is to take the water sample and send it to a high-end analytical laboratory for the analysis.”

Darling says that, because the chemicals are dangerous even at low concentrations, you need a technique that can test for extremely low levels. The sensor they’re behind can detect down to what would equate to one grain of sand in an Olympic-sized swimming pool, or 250 parts per quadrillion.

Typically, this level of inspection would require intensive and expensive lab testing. Their goal is to make these tests accessible for anyone to make sure their water is safe, directly from their home.

“What’s important here is developing new ways,” Darling said, “low-cost, fast ways to determine: Is there PFAS in your water and, if so, how much?”

Other universities in the Chicago area have also delved in to research PFAS. Back in the spring, Northwestern University professor of chemistry SonBinh Nguyen and professor of engineering Tim Wei developed a graphene oxide solution that is water- and oil-resistant and could be a replacement for PFAS in items such as takeout coffee cups.

Adam Harrington contributed to this report.

CLICK HERE FOR MORE INFORMATION

https://www.cbsnews.com/chicago/news/chicago-researchers-portable-tests-forever-chemicals-drinking-water/?intcid=CNM-00-10abd1h

States With the Most Lead Drinking Water Pipes

Nearly a tenth of the nation’s drinking water service lines contain lead, new data shows.

By Chris Gilligan

U.S. News & World Report

States With the Most Lead Pipes

More

A piece of old lead pipe is seen in 2016 in Chicago. (Abel Uribe/Chicago Tribune/Tribune News Service via Getty Images)

TNS

A piece of old lead pipe is seen in 2016 in Chicago.

https://cdn.instaread.co/player?article=states-with-the-most-lead-drinking-water-pipes&publication=usnews.com&article_url=https%3A%2F%2Fwww.usnews.com%2Fnews%2Fbest-states%2Farticles%2Fstates-with-the-most-lead-pipes&version=1759878000000

In a first-of-its-kind report, the Environmental Protection Agency has released a comprehensive assessment on lead pipe infrastructure across the United States, revealing that an estimated total of 9.2 million lead pipes serviced American homes in 2021.

According to the report, lead service lines are estimated to make up over 9% of the entire national service line infrastructure, exposing much of America’s drinking water to lead contamination.

The EPA says there are no safe levels of lead in children’s blood, as lead exposure has been tied to an array of adverse health effects in children, including behavioral problems, lower IQ and slowed growth. In adults, lead exposure is linked with decreased cardiovascular health and kidney function, and lead exposure in pregnant women is linked to premature births.

The bulk of the nation’s lead pipe infrastructure is concentrated in a handful of states, including many of the Rust Belt states in the Great Lakes region. Florida has the most lead service lines in the country, with its 1.16 million lines accounting for 12.6% of the country’s total. Over 50% of the national service lines are concentrated in six states: Florida, Illinois (11.4%), Ohio (8.1%), Pennsylvania (7.5%), Texas (7.1%) and New York (5.4%).

Lead service lines are far less common west of the Mississippi River, with Texas as the lone exception. Notably, California’s service line infrastructure, which serves the largest state population over the third-largest area, has less than 13,500 lead service lines, or about 0.15% of the national total.

Federal law prohibits installing new lead plumbing because of its dangers to health. In 2021, the Biden Administration announced an aggressive plan to replace all lead service lines in the next decade as part of the Bipartisan Infrastructure Law, and earlier this year the EPA announced that $1.2 billion had already been distributed to 23 states to address that goal. But the costs associated with such an effort are significant. Over the next two decades, the EPA report estimates that $625 billion is needed to address the challenges with drinking water infrastructure.

[ EXPLORE: More on Public Water System Violations ]

Lead exposure does not impact all American demographics evenly. The Centers for Disease Control and Prevention published a study in 2021 indicating that non-Hispanic Black or African American children were at particular risk, as well as children living in areas with higher poverty rates.

Although the Safe Drinking Water Act, which was enacted 1974 and amended most recently in 1996, aims to ensure the public’s access to contaminant-free water, large-scale issues with drinking water distribution systems are still prevalent. Spikes in the rates of lead in children’s blood in 2015 sparked the start of a years-long water crisis in Flint, Michigan. The city of Jackson, Mississippi, which endured days with a full water outage last August and September, has ongoing projects to reduce elevated levels of lead in its water supply, and lead contamination has led to crises in Newark, New Jersey, Chicago and Washington, D.C., among other communities.

These are the states with the most lead pipes, according to the EPA:

  1. Florida
  2. Illinois
  3. Ohio
  4. Pennsylvania
  5. Texas
  6. New York
  7. Tennessee
  8. North Carolina
  9. New Jersey
  10. Wisconsin

CLICK HERE FOR MORE INFORMATION

https://www.usnews.com/news/best-states/articles/states-with-the-most-lead-pipes

Local News

Northfield, Minnesota warns residents of unsafe drinking water for infants

By Jason Rantala

In 2019, city officials in Northfield, Minnesota said the town’s water supply tested for high levels of manganese.

In high doses, the metal can cause memory, attention and motor skills problems for adults, and particularly impacts infants, according to the Minnesota Department of Health.

Earlier this year, the city scrapped plans to build a new water treatment facility because costs became too high, rising from $60 million to $83 million.

“Certainly we’re all committed to safe and healthy drinking water here in Northfield,” said Ben Martig, Northfield’s city administrator.

City officials are now advising families with infants under 1 to have them drink bottled water or to treat the water themselves, like with a reverse osmosis system.

Officials said they have been warning residents about the water quality issues for years through multiple press releases.

“We’ve talked with local providers, letting them know to notify pregnant mothers and newborn families that they should be looking at different options for their water and making sure that it is further treated,” said Justin Wagner, the city’s utilities manager.

“It’s unsafe for children under 1 and people who are pregnant, and those are important and valuable people to our community, too,” said Ward 1 City Council Member Kathleen Holmes.

She said water treatment is a city need, and costs for the project will only increase as time passes.

“This is a situation for renters who can’t put in reverse osmosis or can’t afford it,” said Holmes.

Northfield resident Levi Prinzing is the parent of an infant, but said at this point he’s more worried about the financial impacts of a new treatment facility. Prinzing also filters his water.

“I don’t think we need a new treatment plant,” said Prinzing. “The treatment plant is a lot of money and we just raised our taxes a lot.”

“We have to find a way to work together as a council and find a solution that can help bridge that gap, that we can provide safe drinking water for all residents, and hopefully reduce the financial impact or financial burden that it is on residents,” said Holmes.

The City Council may reconsider the water treatment facility in June.

CLICK HERE FOR MORE INFORMATION

https://www.cbsnews.com/minnesota/news/northfield-minnesotas-warns-residents-of-unsafe-drinking-water-for-infants/?intcid=CNM-00-10abd1h

Risk of cardiovascular disease linked to long-term exposure to arsenic in community water supplies

Understanding risk below the current US EPA regulatory standard

Source:Columbia University's Mailman School of Public Health

Summary:Long-term exposure to arsenic in water may increase cardiovascular risk and especially heart disease risk even at exposure levels below the federal regulatory limit, according to new research. A study describes exposure-response relationships at concentrations below the current regulatory limit and substantiates that prolonged exposure to arsenic in water contributes to the development of ischemic heart disease.Share:

    

FULL STORY

Long-term exposure to arsenic in water may increase cardiovascular disease and especially heart disease risk even at exposure levels below the federal regulatory limit (10µg/L) according to a new study at Columbia University Mailman School of Public Health. This is the first study to describe exposure-response relationships at concentrations below the current regulatory limit and substantiates that prolonged exposure to arsenic in water contributes to the development of ischemic heart disease.

The researchers compared various time windows of exposure, finding that the previous decade of water arsenic exposure up to the time of a cardiovascular disease event contributed the greatest risk. The findings are published in the journal Environmental Health Perspectives.

“Our findings shed light on critical time windows of arsenic exposure that contribute to heart disease and inform the ongoing arsenic risk assessment by the EPA. It further reinforces the importance of considering non-cancer outcomes, and specifically cardiovascular disease, which is the number one cause of death in the U.S. and globally,” said Danielle Medgyesi, a doctoral Fellow in the Department of Environmental Health Sciences at Columbia Mailman School. “This study offers resounding proof of the need for regulatory standards in protecting health and provides evidence in support of reducing the current limit to further eliminate significant risk.”

According to the American Heart Association and other leading health agencies, there is substantial evidence that arsenic exposure increases the risk of cardiovascular disease. This includes evidence of risk at high arsenic levels (>100µg/L) in drinking water. The U.S. Environmental Protection Agency reduced the maximum contaminant level (MCL) for arsenic in community water supplies (CWS) from 50µg/L to 10µg/L beginning in 2006. Even so, drinking water remains an important source of arsenic exposure among CWS users. The natural occurrence of arsenic in groundwater is commonly observed in regions of New England, the upper Midwest, and the West, including California.

To evaluate the relationship between long-term arsenic exposure from CWS and cardiovascular disease, the researchers used statewide healthcare administrative and mortality records collected for the California Teachers Study cohort from enrollment through follow-up (1995-2018), identifying fatal and nonfatal cases of ischemic heart disease and cardiovascular disease. Working closely with collaborators at the California Office of Environmental Health Hazard Assessment (OEHHA), the team gathered water arsenic data from CWS for three decades (1990-2020).

The analysis included 98,250 participants, 6,119 ischemic heart disease cases and 9,936 CVD cases. Excluded were those 85 years of age or older and those with a history of cardiovascular disease at enrollment. Similar to the proportion of California’s population that relies on CWS (over 90 percent), most participants resided in areas served by a CWS (92 percent). Leveraging the extensive years of arsenic data available, the team compared time windows of relatively short-term (3-years) to long-term (10-years to cumulative) average arsenic exposure. The study found decade-long arsenic exposure up to the time of a cardiovascular disease event was associated with the greatest risk, consistent with a study in Chile finding peak mortality of acute myocardial infarction around a decade after a period of very high arsenic exposure. This provides new insights into relevant exposure windows that are critical to the development of ischemic heart disease.

Nearly half (48 percent) of participants were exposed to an average arsenic concentration below California’s non-cancer public health goal <1 µg/L. In comparison to this low-exposure group, those exposed to 1 to <5 µg/L had modestly higher risk of ischemic heart disease, with increases of 5 to 6 percent. Risk jumped to 20 percent among those in the exposure ranges of 5 to <10 µg/L (or one-half to below the current regulatory limit), and more than doubled to 42 percent for those exposed to levels at and above the current EPA limit ≥10µg/L. The relationship was consistently stronger for ischemic heart disease compared to cardiovascular disease, and no evidence of risk for stroke was found, largely consistent with previous research and the conclusions of the current EPA risk assessment.

These results highlight the serious health consequences not only when community water systems do not meet the current EPA standard but also at levels below the current standard. The study found a substantial 20 percent risk at arsenic exposures ranging from 5 to <10 µg/L which affected about 3.2 percent of participants, suggesting that stronger regulations would provide significant benefits to the population. In line with prior research, the study also found higher arsenic concentrations, including concentrations above the current standard, disproportionally affect Hispanic and Latina populations and residents of lower socioeconomic status neighborhoods.

“Our results are novel and encourage a renewed discussion of current policy and regulatory standards,” said Columbia Mailman’s Tiffany Sanchez, senior author. “However, this also implies that much more research is needed to understand the risks associated with arsenic levels that CWS users currently experience. We believe that the data and methods developed in this study can be used to bolster and inform future studies and can be extended to evaluate other drinking water exposures and health outcomes.”

Co-authors are Komal Bangia, Office of Environmental Health Hazard Assessment, Oakland, California; James V. Lacey Jr and Emma S. Spielfogel,California Teacher Study, Beckman Research Institute, City of Hope, Duarte, California; and Jared A Fisher, Jessica M. Madrigal, Rena R. Jones, and Mary H. Ward, Division of Cancer Epidemiology and Genetics, National Cancer Institute.

The study was supported by the National Cancer Institute, grants U01-CA199277, P30-CA033572, P30-CA023100, UM1-CA164917, and R01-CA077398; and also funded by the Superfund Hazardous Substance Research and Training Program P42ES033719; NIH National Institute of Environmental Health Sciences P30 Center for Environmental Health and Justice P30ES9089, NIH Kirschstein National Research Service Award Institutional Research Training grant T32ES007322, NIH Predoctoral Individual Fellowship F31ES035306, and the Intramural Research Program of the NCI Z-CP010125-28.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2024/10/241023131603.htm

Scientist on personal mission to improve global water safety makes groundbreaking discovery

Source:University of Bristol

Summary:A study shedding new light on how arsenic can be made less dangerous to humans has the potential to dramatically improve water and food safety, especially in the Global South.Share:

    

FULL STORY

A study led by the University of Bristol shedding new light on how arsenic can be made less dangerous to humans has the potential to dramatically improve water and food safety, especially in the Global South.

For the lead researcher it’s an academic and personal mission because he witnessed first-hand the constant struggle to find clean, arsenic-free water as a child in India.

Lead author Dr Jagannath Biswakarma, Senior Research Associate at the University’s School of Earth Sciences, said: “There are millions of people living in regions affected by arsenic, like I was growing up. This breakthrough could pave the way for safer drinking water and a healthier future.”

Arsenic pollution exposure is a huge environmental and public health issue in southern and central Asia and South America, where people depend on groundwater for drinking and farming. The more toxic and mobile form of arsenic, called arsenite, easily seeps into water supplies and can lead to cancers, heart disease and other serious conditions.

Dr Biswakarma said: “I’ve seen the daily battle for safe drinking water in my hometown Assam. It’s very hard to find groundwater sources that aren’t contaminated with arsenic, so for me this research hits close to home. It’s an opportunity to not only advance science, but also better understand the extent of a problem which has affected so many people in my own community and across the world for many decades.”

Scientists previously believed arsenite could only be turned into the less harmful form, called arsenate, with oxygen. But this new study has shown it can still be oxidised, even in the absence of oxygen, with small amounts of iron which act as a catalyst for oxidation.

Dr Biswakarma said: “This study presents a new approach to addressing one of the world’s most persistent environmental health crises by showing that naturally occurring iron minerals can help oxidise, lowering the mobility of arsenic, even in low-oxygen conditions.”

Study findings revealed that arsenite could be oxidised by green rust sulfate, a source of iron prevalent in low-oxygen conditions, such as groundwater supplies. They also showed this oxidation process is further enhanced with a chemical released by plants and commonly found in soils and groundwater.

“These organic ligands, such a citrate from plant roots, could play a critical role in controlling arsenic mobility and toxicity in natural environments,” Dr Biswakarma added.

The implications of this discovery are particularly significant for regions in the Global South facing some of the world’s highest levels of arsenic pollution. In countries such as India and Bangladesh, the local geology is rich in iron, and reducing conditions often dominate in groundwater systems, leading to high levels of arsenic contamination. In the Ganges-Brahmaputra-Meghna Delta, which spans Bangladesh and eastern India, millions of people have been exposed to arsenic-contaminated groundwater for decades as the chemical enters the water through natural processes.

Dr Biswakarma said: “Many households rely on tube wells and hand pumps, but these systems do not guarantee access to clean water. The water often cannot be used for drinking or other household tasks due to its toxicity, odour, and discoloration. Additionally, there is an ongoing financial burden associated with obtaining new tube wells or hand pumps. As a result, economically disadvantaged families continue to struggle to find safe water for their daily needs.”

Similarly, the Mekong Delta and the Red River Delta, in Vietnam, face ongoing challenges with arsenic pollution, affecting drinking water supplies and agricultural productivity. Rice paddies can become hotspots of arsenic exposure, as the toxic chemical can accumulate in soil and be absorbed by rice plants, posing a further health risk through food consumption.

“The research opens the door for developing new strategies to mitigate arsenic pollution. Understanding the role of iron minerals in arsenic oxidation could lead to innovative approaches to water treatment or soil remediation, using natural processes to convert arsenic into its less harmful form before it enters drinking water supplies,” said co-author Molly Matthews, who worked on the paper during her Masters degree in Environmental Geoscience at the University of Bristol.

Identifying the specific form of arsenic in a sample can be challenging. Even a trace amount of oxygen can convert arsenite into arsenate, so it is vital to protect samples from exposure to air. Thanks to funding from the European Synchrotron Radiation Facility (ESRF) the team was able to conduct these complex experiments at its XMaS synchrotron facility, in Grenoble, France.

Co-author Dr James Byrne, Associate Professor of Earth Sciences, added: “Determining arsenic formation at the atomic level using X-ray absorption spectroscopy was crucial for confirming changes to the arsenic oxidation state. The synchrotron therefore played a pivotal role in supporting our findings, which have potentially broad implications for our understanding of water quality.”

This work at University of Bristol was supported through a UK Research & Innovation (UKRI) Future Leaders Fellowship (FLF) awarded to Dr James Byrne. Further research is now needed to explore how these findings can be applied in real-world settings.

Dr Biswakarma said: “The whole research team worked tirelessly on this project, putting in 24/7 shifts including over Easter to conduct the experiments in France.

“I genuinely believe, with more work, we can find effective possible solutions and we’re already making great inroads to overcoming this big global issue. We’re excited to investigate how this process might work in different types of soils and groundwater systems, especially in areas where arsenic contamination is most severe.”

Finding bold answers to big questions concerning global challenges is at the heart of the University of Bristol’s research. This study cuts across core themes, including advancing equitable and sustainable health, and driving forward social justice.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2024/10/241029120854.htm

The invisible plastic threat you can finally see

Researchers at the University of Stuttgart have developed an “optical sieve” for detecting tiny nanoplastic particles. It works like a test strip and is intended to serve as a new analysis tool in environmental and health research.

Source: Universität Stuttgart

Summary:Researchers in Germany and Australia have created a simple but powerful tool to detect nanoplastics—tiny, invisible particles that can slip through skin and even the blood-brain barrier. Using an “optical sieve” test strip viewed under a regular microscope, these particles reveal themselves through striking color changes.Share:

    

FULL STORY

The Invisible Plastic Threat You Can Finally See
The optical sieve nanoplastic particles fall into holes of the appropriate size in the test strip. The color of the holes changes. The new color provides information about the size and number of particles. Credit: University of Stuttgart / 4th Physics Institute

A joint team from the University of Stuttgart in Germany and the University of Melbourne in Australia has developed a new method for the straightforward analysis of tiny nanoplastic particles in environmental samples. One needs only an ordinary optical microscope and a newly developed test strip — the optical sieve. The research results have now been published in Nature Photonics.

“The test strip can serve as a simple analysis tool in environmental and health research,” explains Prof. Harald Giessen, Head of the 4th Physics Institute of the University of Stuttgart. “In the near future, we will be working toward analyzing nanoplastic concentrations directly on site. But our new method could also be used to test blood or tissue for nanoplastic particles.”

Nanoplastics as a danger to humans and the environment

Plastic waste is one of the central and acute global problems of the 21st century. It not only pollutes oceans, rivers, and beaches but has also been detected in living organisms in the form of microplastics. Until now, environmental scientists have focused their attention on larger plastic residues. However, it has been known for some time that an even greater danger may be on the horizon: nanoplastic particles. These tiny particles are much smaller than a human hair and are created through the breakdown of larger plastic particles. They cannot be seen with the naked eye. These particles in the sub-micrometer range can also easily cross organic barriers such as the skin or the blood-brain barrier.

Color changes make tiny particles visible

Because of the small particle size, their detection poses a particular challenge. As a result, there are not only gaps in our understanding of how particles affect organisms but also a lack of rapid and reliable detection methods. In collaboration with a research group from Melbourne in Australia, researchers at the University of Stuttgart have now developed a novel method that can quickly and affordably detect such small particles. Color changes on a special test strip make nanoplastics visible in an optical microscope and allow researchers to count the number of particles and determine their size. “Compared with conventional and widely used methods such as scanning electron microscopy, the new method is considerably less expensive, does not require trained personnel to operate, and reduces the time required for detailed analysis,” explains Dr. Mario Hentschel, Head of the Microstructure Laboratory at the 4th Physics Institute.

Optical sieve instead of expensive electron microscope

The “optical sieve” uses resonance effects in small holes to make the nanoplastic particles visible. A study on optical effects in such holes was first published by the research group at the University of Stuttgart in 2023. The process is based on tiny depressions, known as Mie voids, which are edged into a semiconductor substrate. Depending on their diameter and depth, the holes interact characteristically with the incident light. This results in a bright color reflection that can be seen in an optical microscope. If a particle falls into one of the indentations, its color changes noticeably. One can therefore infer from the changing color whether a particle is present in the void.

“The test strip works like a classic sieve,” explains Dominik Ludescher, PhD student and first author of the publication in “Nature Photonics.” Particles ranging from 0.2 to 1 µm can thus be examined without difficulty. “The particles are filtered out of the liquid using the sieve in which the size and depth of the holes can be adapted to the nanoplastic particles, and subsequently by the resulting color change can be detected. This allows us to determine whether the voids are filled or empty.”

Number, size, and size distribution of particles can be determined

The novel detection method used can do even more. If the sieve is provided with voids of different sizes, only one particle of a suitable size will collect in each hole. “If a particle is too large, it won’t fit into the void and will be simply flushed away during the cleaning process,” says Ludescher. “If a particle is too small, it will adhere poorly to the well and will be washed away during cleaning.” In this way, the test strips can be adapted so that the size and number of particles in each individual hole can be determined from the reflected color.

Synthesized environmental samples examined

For their measurements, the researchers used spherical particles of various diameters. These are available in aequous solutions with specific nanoparticle. Because real samples from bodies of water with known nanoparticle concentrations are not yet available, the team produced a suitable sample themselves. The researchers used a water sample from a lake that contained a mixture of sand and other organic components and added spherical particles in known quantities. The concentration of plastic particles was 150 µg/ml. The number and size distribution of the nanoplastic particles was also be determined for this sample using the “optical sieve.”

Can be used like a test strip

“In the long term, the optical sieve will be used as a simple analysis tool in environmental and health research. The technology could serve as a mobile test strip that would provide information on the content of nanoplastics in water or soil directly on site,” explains Hentschel. The team is now planning experiments with nanoplastic particles that are not spherical. The researchers also plan to investigate whether the process can be used to distinguish between particles of different plastics. They are also particularly interested in collaborating with research groups that have specific expertise in processing real samples from bodies of water.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2025/09/250910000240.htm

Four billion particles of microplastics discovered in major body of water

Source:University of South Florida (USF Innovation)

Summary:While collecting water samples and plankton, researchers discovered a high concentration of microplastics, which are known to disrupt the marine food chain.Share:

    

FULL STORY

A new study from the University of South Florida St. Petersburg and Eckerd College estimates the waters of Tampa Bay contain four billion particles of microplastics, raising new questions about the impact of pollution on marine life in this vital ecosystem.

This is the first measurement of microplastic abundance and distribution in the region. Researchers hope the findings will provide necessary data to inform the debate around policies to reduce plastic in the marine environment.

Microplastics are tiny plastic particles less than 1/8 of an inch, barely or not at all visible to the eye. They come from the breakdown of larger plastics, such as water bottles, fishing gear and plastic bags, or from synthetic clothing and other items that contain elements of plastic. Previous studies have found these particles in every ocean on the planet and even in the Arctic.

“Very little is known about how much microplastics are out there and the full consequences of these particles on marine life,” said Kinsley McEachern, the first author of the study and a recent Environmental Science and Policy graduate student at USF St. Petersburg. “But emerging research indicates a wide range of impacts on marine ecosystems from the large accumulation of microplastics.”

Since particles are similar size as plankton, filter feeders such as oysters, clams, many fish and some birds ingest microplastics, allowing them to enter the food chain. Persistent organic pollutants, including toxic pesticides, and metals can stick to their surfaces, making ingestion potentially that much more damaging. Effects include cellular damage, reproductive disruption and even death.

The study revealed that the predominant type of these tiny particles in Tampa Bay — in both water and sediment — are thread-like fibers that are generated by fishing lines, nets and washing clothes. Synthetic fibers are released from clothes while they are being laundered, discharged to wastewater treatment plants and eventually released into the bay.

The next largest source are fragments that come from the breakdown of larger plastics.

“These plastics will remain in the bay, the gulf and ocean for more than a lifetime, while we use most plastic bags and bottles for less than an hour,” said David Hastings, Principal Investigator of the study, Courtesy Professor at USF College of Marine Science and a recently retired Professor of Marine Science and Chemistry at Eckerd College. “Although it is tempting to clean up the mess, it is not feasible to remove these particles from the water column or separate them out from sediments.”

“Only by removing the sources of plastics and microplastic particles can we successfully decrease the potential risks of plastics in the marine environment,” added McEachern.

Researchers found the largest concentrations of microplastics in water occurred after intense and long rainfall events, while in sediments the greatest amount of microplastics were located close to industrial sources.

For more than a decade, Hastings led annual research cruises in Tampa Bay with Eckerd College students to collect water samples and plankton. During these trips, he and his students were also seeing small pieces of plastic.

“We were looking at plankton, which form the base of the marine food web. But when we put the samples underneath the microscope, we were astonished to find many brightly colored pieces of microplastic. We wanted to learn more,” said Hastings.

Teaming up with McEachern, who was interested in focusing her graduate research on this issue, USFSP Associate Professor of Chemistry Henry Alegria and the Environmental Protection Commission of Hillsborough County, they set about counting microplastics in the region at 24 stations over a 14-month period. Collecting stations were located at the mouths of major rivers, near industrial facilities and in relatively pristine coastal mangroves. Particles believed to be plastic were probed with a hot dissecting needle. If the material quickly melted or disfigured, the sample was classified as a microplastic.

On average, the study found four pieces of microplastic per gallon of water at all sites, and more than 600 pieces of microplastic per pound of dry sediment. Extrapolating those findings to the entire Tampa Bay estuary, the researchers estimated there are approximately four billion particles in the water and more than 3 trillion pieces in surface sediments.

Researchers say the findings, though substantial, might also be conservative, since collection in the bay occurred several feet below the water surface, likely missing any buoyant microplastics at the surface.

“We collected only a few pieces of Styrofoam, most likely because we sampled below the surface and foam floats at the surface,” explained Hastings.

Plastic pollution in the marine environment has been a concern for decades. However, only recently have scientists started to uncover thwidespread abundance of microplastics in the environment. With mounting physical evidence of plastic pollution, there have been greater calls for action in coastal communities around the world. Recently bans on plastic bags and single-use plastics have been enacted by some local governments in Tampa Bay to reduce marine pollution and protect Florida’s largest open-water estuary.

The findings of billions of particles of microplastics in Tampa Bay waters could bring even greater calls for action and influence future decisions in the region and beyond. Researchers at USF St. Petersburg and Eckerd College are conducting further research to more fully understand microplastic pollution in the marine environment.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2019/09/190912111819.htm

Levels of one ‘forever chemical’ are increasing in groundwater

Source:American Chemical Society

Summary:Rain and water in ponds and lakes slowly seeps into the soil, moving through minute cracks to refill underground aquifers. Per- and polyfluoroalkyl substances (PFAS), often described as forever chemicals, can tag along into groundwater that’s later removed for drinking. Researchers analyzed water from over 100 wells in Denmark for one particularly persistent PFAS: trifluoroacetate. They report steadily increasing levels of the forever chemical in recent decades.Share:

    

FULL STORY

Rain and water in ponds and lakes slowly seeps into the soil, moving through minute cracks to refill underground aquifers. Per- and polyfluoroalkyl substances (PFAS), often described as forever chemicals, can tag along into groundwater that’s later removed for drinking. Researchers in ACS’ Environmental Science & Technology Letters analyzed water from over 100 wells in Denmark for one particularly persistent PFAS: trifluoroacetate. They report steadily increasing levels of the forever chemical in recent decades.

Trifluoroacetate forms when fluorinated gases, such as refrigerants, and fluorinated pesticides partially degrade in the environment. Water passing through air and soil picks up trifluoroacetate, transporting the persistent and mobile compound into groundwater aquifers. However, potable groundwater sources haven’t been widely tested for trifluoroacetate because there isn’t a regulatory limit for it beyond the European Environment Agency’s (EEA) limit on total PFAS in drinking water of 0.5 parts per billion (ppb). So, Christian Albers and Jürgen Sültenfuss wanted to thoroughly assess groundwater in Denmark for this contaminant, looking for potential changes in the past 60 years.

The researchers collected samples from 113 groundwater monitoring wells around Denmark. They analyzed the samples for trifluoroacetate and, using an established tritium-helium isotope method, calculated how long ago the water entered the underground aquifers. Overall, their data showed a trend of increasing trifluoroacetate concentrations since the 1960s. Specifically, groundwater from:

  • Before 1960 had unmeasurable levels.
  • 1960 to 1980 contained 0.06 ppb on average.
  • 1980 to 2000 contained 0.24 ppb on average.
  • 2000 to the 2020s contained 0.6 ppb on average, which exceeds the EEA’s total PFAS limit in drinking water.

The researchers attribute concentration differences within time periods to changing atmospheric deposition, plant uptake and local pesticide application. For example, pesticides that might be precursors for trifluoroacetate have been applied to agricultural areas within Denmark since the late 1960s. On the basis of those observations, the researchers say that trifluoroacetate concentrations could be used to categorize when groundwater entered aquifers, such as after 1985 or before 2000, rather than using more sophisticated and tedious dating methods that require isotopes. Additionally, Albers says some particularly high trifluoroacetate concentrations in groundwater less than 10 years old could suggest local sources have recently become more important, such as fluorinated pesticide applications.

CLICK HERE FOR MORE INFORMATION

https://www.sciencedaily.com/releases/2024/09/240904130857.htm