Sunday, March 22, 2026

Paving Hawaiian roads with recycled plastics and abandoned fishing nets

American Chemical Society

ATLANTA, March 22, 2026 — Hawaii has a plastic problem. The island state faces economic and logistical challenges in recycling plastic waste, including marine debris that lingers in its ocean waters. Researchers in Hawaii are pioneering a method to recycle the islands’ derelict fishing nets and residential plastic trash into asphalt roads. Early demonstrations show that these recycled materials may provide a viable end-of-life fate for the region’s garbage.

Jeremy Axworthy, a researcher at the Center for Marine Debris Research (CMDR) at Hawaiʻi Pacific University, will present the team’s results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2026 is being held March 22-26; it features nearly 11,000 presentations on a range of science topics.

“This work investigates whether it’s responsible to use recycled plastics in Hawaii’s roads,” shares Axworthy. “By reusing plastic waste that is already in Hawaii, we can reduce the environmental and economic impacts of transporting waste plastics from the islands, incinerating it or dumping it in Hawaii’s overflowing landfills.”

Since 2020, Hawaii’s roads have predominantly been paved with polymer-modified asphalt (PMA) to increase pavement strength and durability. Compared to standard asphalt pavement, PMA pavement is more elastic and more resistant to cracking, rutting and water damage — qualities that are especially important for the state’s tropical climate. PMA pavement is made by first melting pellets of styrene-butadiene-styrene (SBS; a type of copolymer) into a sticky, petroleum-based asphalt binder. Then, the PMA binder is tumbled with heated aggregates (rocks and sand) in a mixing drum, causing the PMA binder to fully coat the aggregates.

But why not see if discarded plastics could be incorporated into asphalt pavements as an environmentally friendly disposal option? How would modified pavements made with recycled plastics perform, and would they release microplastics or associated chemicals into the environment? These are the questions the Hawaii Department of Transportation (HDOT) aimed to answer when they reached out to environmental chemist Jennifer Lynch, CMDR director and team lead.

HDOT asked Lynch’s team for two things. The first was to provide derelict fishing nets removed from Hawaii’s marine environment for the creation of recycled plastic-modified asphalt pavements. “Foreign plastic derelict fishing gear is the largest contributor of Hawaii’s marine debris problem,” shares Lynch. “To date, CMDR’s Bounty Project, which pays a financial reward to licensed commercial fishers for marine debris removal, has removed 84 tons of large, derelict fishing gear from the Pacific Ocean.”

HDOT’s second request was to measure possible microplastic shedding from pavements made with plastic waste versus that from standard SBS-modified pavement. “CMDR’s laboratory is equipped with state-of-the-art chemical instrumentation for quantifying and characterizing microplastics in environmental samples,” explains Lynch. “This capability is incredibly unique and impactful, especially when coupled to our marine debris-removal project and our mission to recycle the debris into long-term, locally necessary infrastructure products.”

Once a U.S.-based company converted the waste into products that could be incorporated into asphalt, HDOT took the experimental asphalt mixes to Hawaii’s streets. A local paving company laid down sections of a residential road on the island of Oahu with asphalt pavement containing standard SBS, repurposed polyethylene from Honolulu’s recycling containers and polyethylene from fishing nets. After about 11 months of regular traffic usage, Lynch’s team stepped in to collect road dust samples from each section of pavement to test for microplastic shedding, which could contaminate the surrounding soil.

The researchers processed the road dust using a method that separates different types of polymers from other materials in the dust, including microplastics, larger chunks of plastic and tire rubber. Using pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), they identified and measured the source of the polymers: styrene and butadiene from the standard PMA, polyethylene from the plastic-waste and fishing-net PMA, and isoprene and butadiene rubber from tires.

Initial tests showed that pavements made with recycled polyethylene did not release more polymers than the control pavement made with SBS. Lynch’s team showed this was true during mechanical performance tests with pavement samples as well as in simulated stormwater collected from the experimental road sections. Microplastic-sized particles were detected, but very few of these were identified as polyethylene regardless of the pavement type tested. This is likely because the polymers are melted into the asphalt binder, meaning particles that break off are not plastic alone; they are a mixture of rock, binder and melted polymer chains.

The CMDR team is also comparing the amount of polymers shed from the pavement to the amount of polymers shed by tires in the road dust. “In our initial Py-GC-MS data,” continues Lynch, “we saw tire wear swamps the signal of polyethylene by orders of magnitude, like gigantic peaks! We had to search the weeds of the chromatogram to find signs of polyethylene.”

Additional research is needed to assess pavement durability. But the researchers are hopeful that someday, repurposing used plastics into pavement could help reduce landfill and marine debris in Hawaii.

“Some people think plastic recycling is a hoax — that it doesn’t work; it’s too challenging,” Lynch shares. “But this work demonstrates that recycling can work when society prioritizes sustainability.”

The research was funded by the Hawaii Department of Transportation.

Visit the ACS Spring 2026 program to learn more about this presentation, “Harvesting ocean plastics to pave hawaiian roads: Evaluation of microplastic and plastic additive release from asphalt incorporating recycled plastic from various waste streams,” and other science presentations.

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Title
Harvesting ocean plastics to pave hawaiian roads: Evaluation of microplastic and plastic additive release from asphalt incorporating recycled plastic from various waste streams

Abstract
Polymer modified asphalt (PMA) is used to increase strength and durability of roads. In Hawaii, PMA is typically produced using the virgin co-polymer styrene-butadiene-styrene (SBS). Recycled plastics, such as high-density polyethylene (HDPE), may also be added to asphalt serving to sequester plastic waste. In the state of Hawaii, derelict fishing gear (DFG) is a significant problem, yet it is also a source of HDPE that can be used in recycling. However, asphalt performance and the consequences of adding recycled polymers to asphalt are not well understood. In collaboration with the Hawaii Department of Transportation (HDOT) and the University of Hawaii (UH), the Center for Marine Debris Research (CMDR) are testing the feasibility of using recycled HDPE in asphalt by quantifying microplastics and plastic additives release from roads paved with asphalts made from different combinations of virgin and recycled polymers. The specific asphalt combinations being tested are: SBS (Control-PMA), DFG with and without SBS (DFG-PMA and DFG-neat), Local Waste recycled HDPE with and without SBS (LW-PMA and LW-neat), and Commercially Available, post-industrial recycled HDPE with and without SBS (CA-PMA and CA-neat). Microplastic and plastic additive release under laboratory conditions were performed using a Hamburg Wheel Tracker Test (HWTT) with water sample analyses. Field trials were conducted on a residential road on the island of Oahu, Hawaii. Road dust was swept and analyzed for microplastics by direct analysis and solvent extraction to separate bound plastic from asphalt and plastic additives by water extraction. Microplastic samples utilized pyrolysis gas chromatography mass spectrometry for analysis. Plastic additives are subjected to solid phase extraction with analysis by gas chromatography mass spectrometry. Results produced using these novel analytical methods provide guidance on the use of recycled plastics over virgin plastics in roadways. Moreover, results of this study may provide a viable end of life fate for plastic marine debris, leading to cleaner and healthier oceans.

Sepsis linked to nearly 1 in 5 pediatric hospital deaths in the US

New surveillance approach uses clinical data from electronic health records to track pediatric sepsis across hospitals nationwide

Harvard Pilgrim Health Care Institute

BOSTON, MA — Nearly 1 in 5 pediatric hospital deaths in the United States involve sepsis, according to a new national study published March 22 in JAMA. The study also found that sepsis occurs in about 1 in every 75 pediatric hospitalizations and that more than 1 in 10 children with sepsis die during hospitalization.

Based on these findings, the authors estimate that more than 18,000 hospitalized children in the United States have sepsis each year, including more than 1,800 who do not survive to discharge.

The study, “National Estimates of Pediatric Sepsis in US Hospitals Using Clinical Data,” was led by investigators from the SEPSIS Center at the Harvard Pilgrim Health Care Institute, the Children’s Hospital of Philadelphia, and Nemours Children’s Hospital, Delaware, with contributions from multiple collaborating health systems across the country. The research was supported by funding from the Centers for Disease Control and Prevention (CDC).

A New Way to Measure Pediatric Sepsis

Sepsis is a life-threatening condition that occurs when the body’s response to infection causes damage to its own organs. Although sepsis is widely recognized as a leading cause of death in both adults and children, its true burden has historically been difficult to measure reliably.

For many years, researchers relied on hospital billing codes to identify sepsis cases. However, diagnosis and coding practices vary across hospitals and are changing over time, leading to uncertainty about how often sepsis truly occurs.

To address this challenge for children, the research team developed a new surveillance definition called Pediatric Sepsis Event (PSE). The definition builds on the CDC’s Adult Sepsis Event surveillance framework and adapts the recently developed Phoenix pediatric sepsis clinical criteria into a scalable approach that uses objective clinical data from electronic health records—including laboratory results, antibiotics, and markers of organ dysfunction—to generate consistent estimates of pediatric sepsis across hospitals nationwide.

“Improving outcomes starts with measuring the problem accurately,” said Chanu Rhee, MD, MPH, Harvard Medical School associate professor at the Harvard Pilgrim Health Care Institute and one of the two lead authors of the study. “By building a standardized national surveillance framework based on objective clinical data, we can now reliably track how often pediatric sepsis occurs and how many children are affected, creating a stronger foundation for prevention and improvement.”

Key Findings

Researchers analyzed 3.9 million pediatric hospitalizations from 2016 through 2023 across hundreds of hospitals and health systems. The Pediatric Sepsis Event definition was also validated through physician chart review and was found to be more accurate than identifying sepsis using billing codes.

Key findings included:

Sepsis occurred in 1.3% of pediatric hospitalizations (approximately 1 in every 75 hospitalized children)
More than 1 in 10 children with sepsis died during hospitalization
Nearly 1 in 5 pediatric hospital deaths involved sepsis
Rates of pediatric sepsis and associated mortality remained relatively stable nationwide between 2016 and 2022

The study also found that most pediatric sepsis cases were present on admission, but a smaller yet notable proportion developed during hospitalization and were associated with higher mortality. These findings highlight the importance of hospitals strengthening both early recognition and infection prevention efforts.

Why This Matters

The study provides the first standardized national estimates of pediatric sepsis based on clinical data from U.S. hospitals and establishes a scalable framework for tracking pediatric sepsis across health systems.

“Sepsis remains one of the leading causes of serious illness and death among children,” said Scott Weiss, MD, MSCE, division chief of critical care medicine at Nemours Children’s Hospital and one of the two senior authors of the study. “Having a reliable way to measure pediatric sepsis across hospitals using criteria aligned with consensus clinical and research definitions is an essential step toward improving care, guiding prevention and policy efforts, and ultimately saving lives.”

About the Harvard Pilgrim Health Care Institute’s Department of Population Medicine
The Harvard Pilgrim Health Care Institute's Department of Population Medicine is a unique collaboration between Harvard Pilgrim Health Care and Harvard Medical School. Created in 1992, it is the first appointing medical school department in the United States based in a health plan. The Institute focuses on improving health care delivery and population health through innovative research and education, in partnership with health plans, delivery systems, and public health agencies. Follow us on Bluesky, X, and LinkedIn.

Journal

JAMA

Article Title

National Estimates of Pediatric Sepsis in US Hospitals Using Clinical Data

Article Publication Date

22-Mar-2026

Fiber-optic sensors reveal how farming destroys soil's natural structure

Chinese Academy of Sciences Headquarters

Soil is often perceived simply as "dirt," but in reality, it is a dynamic, living system that acts as the Earth's natural sponge. Unfortunately, common agricultural practices—including deep plowing and the use of heavy machinery—can severely disrupt this natural system, according to a new study led by Dr. SHI Qibin from the Institute of Geology and Geophysics of the Chinese Academy of Sciences, in collaboration with international partners.

The study, published in Science on March 19, shows that healthy soil contains a natural internal "plumbing" network of microscopic pores and channels that allow water to infiltrate deeply into the ground, where it becomes available to plant roots. Frequent plowing or heavy tractor traffic not only disrupts soil structure but also reduces its ability to help crops withstand both flooding and drought.

The team used a novel technique to observe subsurface soil processes without excavation. The researchers converted standard fiber-optic cables—similar to those used in high-speed internet networks—into a large-scale sensor array installed across an experimental farm at Harper Adams University in the United Kingdom. By using the array to detect tiny ground vibrations generated by water flow, the researchers were able to monitor water movement through the soil minute by minute.

Using high-resolution fiber-optic data, they observed that rainfall tends to pool near the surface in heavily cultivated soil. Because water remains shallow, it evaporates rapidly in sunlight, leaving deeper soil layers dry. By contrast, undisturbed soils act as efficient natural filters, quickly absorbing water and storing it in deeper layers where plants can access it during dry periods.

To explain these observations, the research team developed a dynamic capillary stress model that assumes an "ink-bottle effect" within soil pore structures. In other words, water flows into a pore (bottle) with ease, but flows out with more difficulty. These differences are attributable to capillary forces that hold soil together more or less strongly, depending on whether the soil is drying or wetting—even when overall moisture content remains the same.

This model is much more complex than traditional soil mechanics, which generally assumes that soil strength depends primarily on total water content.

"Rather than a simple collection of particles, soil is a porous medium in which the structure functions like capillary vessels within the water cycle," Dr. SHI explained.

The findings underscore the need to rethink agricultural land management. Excessive tillage and soil compaction caused by heavy machinery do not merely rearrange soil particles; they break the invisible mechanical bonds that allow soil to breathe, circulate water, and maintain ecological stability.

Preserving these natural structures will be critical to helping crops adapt to increasingly extreme weather conditions driven by climate change, the researchers explained.

The study is noteworthy for introducing distributed fiber-optic sensing—and the larger field of agroseismology—to assess the health of soil water systems without physically disturbing the land. By "listening" to the Earth in this way, scientists and farmers will be able to "diagnose" agricultural soil conditions in real time and develop more resilient strategies for sustainable food production.

Journal

Science

DOI

10.1126/science.aec0970

Article Title

Agroseismology and the impact of farming practices on soil hydrodynamics

Article Publication Date

19-Mar-2026

When the Earth moved

Study shows movement of tectonic plates 3.5 billion years ago

Harvard University

By Kermit Pattison / Harvard Staff Writer

The history of the Earth is written on the great tablets of tectonic plates.

The motions of plates shaped land masses, formed oceans, and created the varied climates and habitats that set the stage for evolution and the diversity of life.

But this grand drama begins with a deep mystery: just when did the continental and oceanic plates begin to drift? Did the lithosphere begin to move soon after the formation of the Earth 4.5 billion years ago or only in the last billion years?

A new study by Harvard geoscientists shows the oldest-yet direct evidence of plate movement by 3.5 billion years ago. In a study published March 19 in Science, the team found that plate movements—though not necessarily the modern type—shaped the early history of our planet.

“There has been a huge range of ages suggested for timing,” said lead author Alec Brenner, PhD ’24, who conducted the research in the Department of Earth and Planetary Sciences (EPS) in the Harvard University Kenneth C. Griffin Graduate School of Arts and Sciences. “With this study, we're able to say three and a half billion years ago, we can see plates moving around on the Earth surface.”

The new revelations came from some of the oldest well-preserved rocks in the world, the Pilbara Craton in western Australia, which contains formations from the Archean Eon when the Earth was hosting early microbial life and under heavy bombardment by astronomical objects. The Pilbara area contains evidence of some of the earliest known life, stromatolites and microbialite rocks deposited by single-celled organisms such as cyanobacteria.

A team led by Roger Fu, Professor of Earth and Planetary Sciences at Harvard University, has been conducting research in East Pilbara since 2017. Fu specializes in paleomagnetism, a branch of geophysics that examines changes in the Earth’s magnetic fields to reconstruct the early history of the planet. Last year, they published a paper about an ancient meteor impact at the same site.

In addition to revealing the properties of the Earth’s magnetic field, paleomagnetism can also be used to track the motions of plates. By analyzing the magnetic signals of ancient mineral grains, the researchers can infer the orientation and latitude of the rocks at the time of formation—thus using the ancient samples like paleo GPS units.

“Almost everything unique about the Earth has something to do with plate tectonics at some level,” said Fu. “At some point, the Earth went from something not that special, just another planet in the solar system with similar materials, to something very special. A very strong suspicion is that plate tectonics started Earth down this divergent track.”

In the new study, the researchers analyzed more than 900 rock samples collected from more than 100 sites scattered across an area called the North Pole Dome.

They extracted cylindrical samples or “cores” using an electric drill with a hollow bit and diamond teeth, kept cool by a hand-pump garden sprayer. Afterwards the position of the sample was precisely recorded with an instrument inserted into the hole containing a compass and goniometer (a device for measuring angles).

Back at Harvard, the cores were sliced into sections like cookies, lined up on trays, and placed in a magnetometer, a machine that can measure magnetic signals 100,000 times more faint than a compass needle. The samples were repeatedly measured while being heated to progressively hotter temperatures up to 590 degrees Celsius until the magnetite minerals lost their magnetization. The step-by-step heating allows researchers to isolate magnetic signals from different periods in the rock’s history. All told, the analysis took about two years.

“We took a really big gamble,” said Brenner, now a postdoc at Yale. “Demagnetizing thousands of cores takes years. And boy, did it pay off! These results were beyond our beyond our wildest dreams."

In ferromagnetic minerals, the orientation of the electrons serves like a compass needle pointing towards the magnetic pole. The electron orientation also provides hints about the position on the three-dimensional globe relative to the magnetic pole when the rock formed—thus providing an indication of latitude.

By analyzing a series of rocks spanning 30 million years just after 3.5 billion years ago, they found that part of the East Pilbara formation shifted in latitude from 53 degrees to 77 degrees—a drift of tens of centimeters annually over several million years—and rotated clockwise by more than 90 degrees. (Because the magnetic pole occasional reverses, it remains uncertain whether this motion occurred in the northern or southern hemisphere.) Within about 10 million years, the motion slowed and followed by a period of little motion.

To compare this motion with Archaean sites elsewhere, the researchers examined a contemporary site in South Africa, the Barberton Greenstone Belt. Previous paleomagnetic studies showed that the latter was located near the equator and nearly stationary during the same time interval. Apparently the two distant regions had different patterns of drift.

In the modern world, the North American and Eurasian plates now are moving away from each other by about 2.5 centimeters, or 1 inch, per year.

It remains an open question about when and how the Earth took on its current form of plate tectonics, which geophysicists call an “active lid.” Various theories posit that the early Earth had a “stagnant lid” (a single unbroken global plate), a “sluggish lid” (slowly moving plates), or “episodic lid” (plates moving sporadically). The new study rules out a stagnant lid but cannot distinguish which model of plate movement was most likely; the Fu team is pursuing additional studies to answer this question.

“We're seeing motion of tectonic plates, which requires that there were boundaries between those plates and that the lithosphere wasn't some big, unbroken shell across the globe, as a lot of people have argued before,” said Brenner. “Instead, it was segmented into different pieces that could move with respect to each other.”

The team also discovered the oldest-known case of a geomagnetic reversal—a phenomenon in which the magnetic field of the planet occasionally flipped. After a reversal, a compass needle would point south instead of north.

This phenomenon is believed to be governed by the “dynamo action” involving the convection of molten iron in the Earth core that produces electrical currents and magnetic fields. The last reversal occurred about 780,000 years ago.

Fu said the new evidence suggests that 3.5 billion years ago, reversals occurred less frequently than in more recent history. “It's not by itself conclusive, but it suggests that maybe the dynamo was in a slightly different regime than today,” he said.

Journal

Science

DOI

10.1126/science.adw9250

Article Title

Paleomagnetic detection of relative plate motions and an infrequently reversing core dynamo at 3.5 Ga

Article Publication Date

19-Mar-2026

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Sunday, March 22, 2026

Paving Hawaiian roads with recycled plastics and abandoned fishing nets

Sepsis linked to nearly 1 in 5 pediatric hospital deaths in the US

Journal

Article Title

Article Publication Date

Fiber-optic sensors reveal how farming destroys soil's natural structure

Journal

DOI

Article Title

Article Publication Date

When the Earth moved

Journal

DOI

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Article Publication Date

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