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March 12, 2026

Hearing loss is often called a dementia risk factor – here’s what the research really shows

Source: The Conversation – UK – By Emma Broome, Senior Research Fellow, University of Nottingham

Hearing loss and dementia affect millions of people worldwide. But headlines describing hearing loss as the “leading mid-life risk factor” for dementia can be misleading. They often oversimplify complex science, and risk confusing people who are trying to understand what hearing loss can mean for brain health.

Research shows that hearing loss and cognitive decline frequently occur together. Cognitive decline refers to worsening memory and thinking skills.

While these two conditions are linked, we still do not fully understand why. Several biological and social factors are likely to be involved, and they probably interact in complex ways. What we do not yet have is clear evidence that hearing loss directly causes dementia.

Hearing loss is extremely common. Around 430 million people worldwide live with disabling hearing loss, and this number is expected to rise to more than 700 million by 2050. Dementia affects 57 million people globally, with prevalence increasing with age. As populations live longer, more people will experience one or both conditions.

Some of the confusion arises from how dementia risk is calculated and reported. Age and genetics account for much of overall risk, alongside factors such as cardiovascular health, education and social isolation. Hearing loss is one part of this broader picture, which means its role can be misinterpreted when statistics are presented without context.

Another source of misunderstanding is how research findings are described. The Lancet commission on dementia uses a measure called the “population attributable fraction”. This estimates how many dementia cases might be linked to a particular factor, in this case hearing loss. It does not mean that a person with hearing loss will develop dementia.

The figure reflects both how common hearing loss is, and how strongly it is associated with dementia. Because hearing loss is so widespread, it can appear to account for a large proportion of cases at population level, even though the individual risk for most people remains relatively modest.

Clear communication is therefore essential. Hearing aids and other devices should not be promoted as guaranteed ways to prevent dementia. Their main value lies in the broader benefits they provide, including improved communication, stronger social connections and better quality of life. These factors can support cognitive health, but they are not proven protective treatments.

Overstating the link between hearing loss and dementia may create unrealistic expectations. It may also discourage some people from seeking help because of stigma – particularly if hearing loss becomes framed primarily as an early sign of cognitive decline, rather than as a common and treatable condition.

How hearing loss might affect the brain

Researchers have proposed several ways in which hearing loss could influence cognitive decline. Hearing difficulties do not simply make conversations harder. They can also alter how the brain processes information.

When sounds are difficult to hear, the brain must work harder to interpret them. This increased effort may leave fewer mental resources available for memory and thinking. Over time, reduced sound input may also affect how certain brain regions function, similar to how a muscle weakens when it is used less.

Hearing difficulties can also affect social participation. Struggling to follow conversations may lead to withdrawal, loneliness or depression, all of which are linked to a higher risk of dementia. At the same time, shared underlying factors such as ageing, vascular disease and genetics may contribute to both hearing loss and dementia.

The picture is complex. These processes are likely to interact differently across people and stages of life, meaning dementia risk is highly individual rather than uniform.

Can hearing aids prevent dementia?

Hearing aids and cochlear implants improve access to sound. However, evidence that they prevent dementia or significantly slow cognitive decline remains limited.

Clinical trials have generally been small and inconclusive, while observational studies show mixed results. Some suggest slower cognitive decline among long-term hearing aid users, but these studies cannot fully account for other influences such as health status, education or income.

That does not mean hearing aids are unimportant. They can make a substantial difference to daily life by helping people follow conversations, remain socially connected and maintain independence. For people already living with dementia, improved hearing can support communication and wellbeing.

Hearing loss often occurs alongside dementia, and when unaddressed it can reduce the effectiveness of other forms of support. Difficulty hearing can make group activities, therapy sessions and social programmes harder to engage with. By improving access to sound, hearing aids may help people benefit more fully from existing care.

Most research on hearing loss and dementia has been carried out in high-income countries. Many studies exclude minority ethnic groups, people in lower-income settings and those living in care homes. This matters because the risk, experience and management of both conditions vary across populations.

Around 80% of people with hearing loss live in low and middle-income countries, and the fastest growth in dementia is expected in these same regions. Without more inclusive research, understanding will remain incomplete and interventions may fail to reach those who need them most.

The relationship between hearing loss and dementia is still evolving. What is clear is that hearing loss affects far more than just cognition. Supporting people to hear better can help them stay connected, engaged and independent. These benefits matter at every stage of life.

Emma Broome receives funding from an NIHR Development and Skills Enhancement Awards (NIHR306142) and a research grant from WS Audiology A/S.

– ref. Hearing loss is often called a dementia risk factor – here’s what the research really shows – https://theconversation.com/hearing-loss-is-often-called-a-dementia-risk-factor-heres-what-the-research-really-shows-276246

March 12, 2026

Nicotine: the latest wellness hack

Source: The Conversation – UK – By Dipa Kamdar, Senior Lecturer in Pharmacy Practice, Kingston University

If you spend any time on social media, you may have noticed a curious trend: wellness influencers singing the praises of nicotine. Not smoking or vaping but nicotine patches and pouches, repackaged as cognitive enhancers, productivity boosters and even weight-loss aids. But does the science support this rebrand, or are we watching a familiar substance undergo a very modern makeover?

Nicotine is primarily a stimulant and derived from the tobacco plant. Small amounts of nicotine are also found in other members of the nightshade family, including tomatoes, aubergines, potatoes and green peppers. However, the levels in these foods are minimal compared with those in tobacco.

Nicotine works by latching on to specific receptors found throughout the body, triggering the release of various brain chemicals such as dopamine, noradrenaline, and serotonin. These receptors, along with a chemical messenger called acetylcholine, play an important role in attention, learning and memory.

The evidence on whether nicotine can enhance cognitive performance is mixed. One large review of 41 trials involving healthy adults – both non-smokers and smokers – found that nicotine produced small improvements in areas such as fine motor skills, attention and aspects of short-term and working memory.

An animal study demonstrated nicotine increased working memory and boosted levels of brain-derived neurotrophic factor, a protein important for learning and brain resilience. However, other research shows that in healthy non-smokers, nicotine often has neutral or even negative cognitive effects.

This difference comes down to starting point. People who already have cognitive difficulties have more room to improve, while those with healthy brain function are already performing close to their best. Because of this, nicotine is unlikely to offer any real benefit to people who don’t have cognitive impairments.

Small experimental studies have explored whether nicotine patches might help people with mild cognitive impairment, with one trial reporting slight improvements in memory test scores over six months. Research suggests nicotine may have protective effects in neurodegenerative diseases like Alzheimer’s and Parkinson’s, partly because it reduces inflammation, prevents cell death and supports cognitive function.

Nicotine has also been linked to weight loss and reduced appetite. It appears to influence the parts of the brain that control hunger and makes the body burn more energy by triggering the release of stimulating hormones like adrenaline. While some animal studies suggest nicotine can reduce body weight by speeding up fat burning, there is not yet strong evidence that this holds true in humans

Where nicotine is useful is in smoking cessation. Nicotine replacement therapy is an effective way to help people stop smoking. But this benefit comes from reducing exposure to tobacco smoke, which contains a cocktail of chemicals and cancer-causing agents – not from nicotine itself being healthy.

A woman putting nicotine gum in her mouth. — An effective way to quit smoking.
Andrey_Popov/Shutterstock.com

Highly addictive

Nicotine is not harmless and regular use can lead to dependence. Nicotine activates receptors in the brain that trigger the release of several chemical messengers, including dopamine (the so-called feel-good hormone). This surge in dopamine creates the pleasurable sensations and reinforcement that contribute to nicotine’s addictive effects.

Studies in animals show using nicotine during the teenage years can lead to long lasting changes in the brain and behaviour, including higher risk of other drug use, reduced attention and mood problems.

Teenagers have more nicotine receptors in the brain’s reward areas than adults, which makes nicotine’s effects stronger and the developing brain more vulnerable. Similar effects can be seen in a developing baby during pregnancy.

Common side-effects of using nicotine include nausea, vomiting and headaches. It can also cause more serious heart and blood-vessel harms.

Nicotine triggers the release of chemicals such as adrenaline and noradrenaline, and studies show that higher levels of these can raise heart rate, increase blood pressure and make the heart work harder.

Nicotine also damages the inner walls of blood vessels by causing inflammation, raising blood pressure and disrupting normal blood vessel function. The evidence is clear that no nicotine product is safe for the heart and cardiovascular system – a conclusion now officially backed by major health organisations, including the World Health Organization.

Is nicotine safer without smoke? Yes. Is it safe? No.

Reduced harm is not the same as benefit. The scientific picture is complicated: possible cognitive effects, potential therapeutic avenues, but clear risks and strong addictive potential.

The science does not support using nicotine as a cognitive enhancer or lifestyle supplement for healthy adults. What it does support is using nicotine replacement therapy to help people stop smoking. Outside that context, the risks outweigh the hype. Wellness trends come and go, but addiction is far harder to shake.

Dipa Kamdar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Nicotine: the latest wellness hack – https://theconversation.com/nicotine-the-latest-wellness-hack-276614

March 12, 2026

Everybody to Kenmure Street: how a feisty Glasgow neighbourhood beat a ‘secret’ immigration raid

Source: The Conversation – UK – By Trish Reid, Professor of Theatre and Performance, University of Reading

The kind of protests that loom large in the collective imagination tend to be compact and dramatic. Everybody to Kenmure Street, Felipe Bustos Sierra’s energising and inspiring film about a spontaneous act of collective civil disobedience in Glasgow, documents just such an event.

At a time when mobile phone footage shared by citizen activists is proving increasingly vital in holding authority to account, it also feels extraordinarily prescient. Most obviously in the US, where the film recently won the world cinema documentary special jury award for civil resistance at the Sundance Film Festival.

Bustos Sierra’s debut was the 2018 documentary Nae Pasaran, about a group of Scottish Rolls-Royce workers who, in 1974, refused to repair jet engines for the Chilean air force in protest against the violent Pinochet regime. It won a Bafta for best feature film. Unsurprisingly, Bustos Sierra handles his material with confidence.

Everybody to Kenmure Street begins with a black and white montage. Children play in the back courts of tenement slums. Suffragettes demand the right to vote. The intense heat of the Glasgow’s blast furnaces sends sparks flying. Crowds march against the installation of a nuclear deterrent on the Clyde. Riveters raise their hammers in synchronised rhythm in the city’s famous ship yards. Glasgow’s industrial heritage and its proud history of protest are established as the film’s backdrop.

As the film moves from black and white to colour, we find ourselves on a tenement-lined street in the Pollokshields area of the city. It is early morning on May 13 2021. An immigration enforcement vehicle has just pulled up on Kenmure Street, and two Indian men have been arrested for possible infringements.

Priti Patel, the UK home secretary, had been aggressively doubling down on the hostile environment promoted by her predecessor Theresa May. The dawn raid had been approved without the knowledge of the Scottish government in Holyrood because immigration legislation and policy are reserved to Westminster. Among other things, then, Everybody to Kenmure Street exposes some of the tensions in the devolution settlement.

This intrusion into one of Scotland’s most ethnically diverse areas, with a large Muslim population, on what also happened to be Eid al-Fitr – the feast day that celebrates the end of Ramadan – was understandably experienced by many as a deliberate provocation.

As Bustos Sierra’s evocative film documents, it quickly becomes the trigger for an extraordinary act of communal resistance. A kind of social media-enabled mass sit down, it results in an eight-hour stand-off with immigration officials and the police, and the eventual release, without charge, of the two men.

Making extensive use of donated mobile phone footage, Bustos Sierra documents the heartwarming combination of improvised tactics and community-based solidarity that won the day from the level of the street itself.

As the day progressed, the number of protestors grew from a handful to dozens, to hundreds and eventually a couple of thousand. Word spread and a number of well-known figures arrived on the scene, perhaps most significantly, the activist and human rights lawyer Aamer Anwar who eventually negotiated the men’s release.

The power of ordinary people

At its most affecting though, Everybody to Kenmure Street is a film about the decency and moral courage of ordinary Glaswegians. Having looked out of their windows and spotted the immigration van, a small number of residents decided to act.

They came out into the street, challenged the officials present, created an obstruction by sitting down, and began texting and posting on social media. Crucially, just after 9am an activist, known only as “Van Man”, crawled under the police vehicle and attached himself to the axle preventing the immigration officers from driving away.

His timely action allowed others to gather, and he was described by many as the hero of the day. Because he wishes to remain anonymous, his words are spoken, here, by the film’s executive producer, the actor and activist Emma Thompson, who looks directly to the camera while adopting a position that echoes the cramped conditions Van Man endured for eight hours.

The Scottish actor Kate Dickie similarly gives voice to the off-duty NHS worker who tended him for most of the day. “The fact that I’m a nurse,” she explains, “gives me a level of protection that other people wouldn’t experience”. It’s difficult to hear her words without thinking of Alex Pretti, the 37-year-old intensive care nurse shot and killed by an ICE agent in Minneapolis, in January of this year.

The absolute horror of events in that city make the dénouement of Bustos Sierra’s film all the more remarkable. Police Scotland, who by the end of the day were in attendance in high numbers, simply agreed to let the men go in order to avert any kind of violent confrontation.

If all this sounds wildly utopian, Bustos Sierra is careful not to allow his adopted home town to become too pleased with itself. Picking up on some of the threads laid down in the opening montage, he uses the middle section to stress Glasgow’s mixed legacies.

While the city’s radical tradition is certainly honoured, from its early opposition to apartheid to its proud history of trades unionism, the film also stresses that its mercantile and industrial wealth, like that of Bristol, Liverpool and London, was built on the labour of enslaved people.

In this way a connection is made between the brown men held in the van, who are victims of an aggressive immigration policy, and the historical victims of colonialism who were also predominantly people of colour.

Given that our news feeds are currently full of images reinforcing the reality that black and brown lives are less grievable than white ones, this connection seems an especially vital one to make. An important film, everybody should see Everybody to Kenmure Street.

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Trish Reid does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Everybody to Kenmure Street: how a feisty Glasgow neighbourhood beat a ‘secret’ immigration raid – https://theconversation.com/everybody-to-kenmure-street-how-a-feisty-glasgow-neighbourhood-beat-a-secret-immigration-raid-275713

March 12, 2026

How biological invasions are silently remodelling ecosystems

Source: The Conversation – France – By Franck Courchamp, Directeur de recherche CNRS, Université Paris-Saclay

Many of the most damaging invasions do not simply subtract species; they fundamentally remodel the environment, altering habitats, rewiring interactions, and shifting processes in ways that species lists alone cannot reveal.

Consider the goat, the horse or the deer, introduced to many islands around the world. While their voracious grazing can indeed drive native flora towards local extinction, the legacy is etched deeper into the land.

These invasive herbivores compact the earth, accelerate erosion, open up the undergrowth and modify fire regimes, scarring the landscape long after the herds are gone. These systemic changes threaten biodiversity just as profoundly as the loss of any single species.

To navigate this complexity, invasion scientists have increasingly turned to the Environmental Impact Classification for Alien Taxa (EICAT). This pioneering framework marked a significant leap forward, offering a transparent, evidence-based method to rank “invaders” by the severity of their toll on native species, from negligible effects to local extinctions.

However, EICAT operates with a specific blind spot: it is strictly species-orientated. It assigns a single global severity score to an invader, usually based on the worst-case scenario recorded in its invasive ranges. While powerful for global prioritisation, this approach can overlook the complexities in specific, local ecosystems, each with unique vulnerabilities. As a recent study published in PLOS biology illustrates, there is cause for further investigation.

The invisible architecture of invasions

In addition, biological invasions generate a spectrum of impacts extending far beyond direct effects on native species seen in typical assessments. In our recent synthesis published in 2025, we catalogued 19 distinct types of environmental impacts.

When examining all of the well-documented impacts, it became obvious that most structural changes operate at the level of communities, ecosystems or physical processes.

Crucially, twelve of these categories concern scales broader than the actual species: nutrient cycling, habitat structure, or the physical properties of soil and water, for instance whose impacts are therefore underestimated.

Three distinctive levels of structural changes can be distinguished:

individuals and populations,
assemblages of different species,
ecosystem functioning, or abiotic conditions – in other words non-living physical or chemical parts of the environment that affect living organisms such as pollination and fire regimes.

Nutria are a species renown for its ecosystem engineering skills.
Max Saeling

Despite being widespread and well documented, these structural changes remain largely unclassified by frameworks that focus ultimately on native species loss.

This omission is critical because many invasive species act as “ecosystem engineers”, organisms that do not merely live in an environment but actively modify it, influencing the fate of entire communities.

To capture this nuance, from our recent research we developed a complementary assessment tool: EEICAT, the Extended Environmental Impact Classification for Alien Taxa.

From the invader to the invasion

EEICAT is not a replacement but an evolution. It brings a necessary expansion in impact assessments, while seeking simplicity and integration. It is based on EICAT, but it shifts the unit of assessment from the invasive species to the invasion event. Under this framework, all 19 impact types can now be considered and an invasive population can be assigned one or multiple severity categories, at any ecological level. Under EEICAT, the loose threads of evidence from multiple impacts can now be woven to reflect the unique tapestry of effects on native species, communities, processes, and even abiotic conditions.

The necessity of this distinction is vivid in aquatic systems invaded by zebra mussels (Dreissena spp.). In too many lakes, these molluscs threaten native mussel populations through competition and biofouling, a classic impact well captured by standard assessments. Yet, simultaneously, they are transforming the environment itself: filtering water, lowering turbidity, altering nutrient cycles, and triggering cascading shifts in vegetation and food webs. EEICAT allows us to map both the direct blow to native biodiversity and the systemic reengineering of the lake, within a single framework.

Zebra mussels (*Dreissena polymorpha*) attached to native mussels.

A similar logic applies to the terrestrial realm. The Argentine ant (Linepithema humile) is notorious for displacing native ants, simplifying communities into ghost towns, devoid of the usually numerous native ant species. But its influence ripples further. By disrupting mutualisms between plants and insects, these invaders alter seed dispersal, pollination, invertebrate assemblages, and even soil processes. These indirect, community-level impacts often differ in severity across invasion events, depending on climate, habitat integrity and recipient ecosystems. You can therefore assess several impacts per invasion, and characterise the specificities of each invasion: with a case-based approach.

invasive ant supercolony or ants tending aphids.
Alexander Wild (reuse prohibited without authorisation)

Context is everything

The plant kingdom offers some of the clearest arguments for an event-based approach. Acacia species, introduced globally, act as ecological chameleons. In South Africa, they are aggressive suppressors of native flora, or “fynbos”, and transformers of soil chemistry through nitrogen enrichment.

In Mediterranean Europe, the same Acacia dealbata species, commonly known as mimosa, may exert moderate competitive pressure but still alter fire regimes, litter accumulation and hydrology.

EEICAT provides a straightforward way to document these contrasts, where all evidence counts in helping to assess the severity of each particular invasion.

Reinterpreting the ecological history of biological invasions

Importantly, adopting EEICAT does not mean starting from scratch. We can leverage decades of existing impact studies, and even previous EICAT impact assessments could be adapted. The framework simply translates qualitative ecological evidence into a broader set of categories that span biological, community, and abiotic levels. It even uses the same five levels of severity, from “minimal concern” to “massive concern”, with the same guiding decision rules. This compatibility allows us to reinterpret the history of invasion ecology through a wider lens.

Because EEICAT is case-specific, it enables us to track how a single species behaves differently across regions, or how multiple invaders compound pressure on a single ecosystem. It reveals patterns of cumulative stress and ecosystem vulnerability that global scores simply cannot articulate.

Biological invasions are not merely about losing species; they are also about the silent rewriting of ecosystems. From the chemistry of the soil to the rhythms of wildfires, their impacts ripple through the environment long after their arrival. By embracing the Extended EICAT framework, we can finally capture the full scope of how invasive species really impact ecosystems, and tailor management strategies to the complex realities of the living world, with each invasion, one by one.

Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the Axa Research Fund – now part of the Axa Foundation for Human Progress – has supported over 700 projects around the world with researchers from 38 countries on key environmental, health & socioeconomic risks, like this project led by Franck Courchamp. To learn more, visit the website of the AXA Research Fund or follow @ AXAResearchFund on LinkedIn.

Franck Courchamp received funding from The AXA Research Fund.

Laís Carneiro received funding from AXA Research Fund.

– ref. How biological invasions are silently remodelling ecosystems – https://theconversation.com/how-biological-invasions-are-silently-remodelling-ecosystems-277703

March 12, 2026

China’s new tariff-free regime for Africa: the potential upside and downside

Source: The Conversation – Africa – By Lauren Johnston, Associate Professor, China Studies Centre, University of Sydney

China’s President Xi Jinping announced in February 2026 that from 1 May China would be granting zero-tariff treatment to 53 African countries. (That is all of them bar Eswatini, which supports Taiwan.)

China-Africa trade reached US$348 billion in 2025, up 17.7% from 2024. Chinese exports to Africa dominate trade flows, and amounted to US$225 billion, an increase of 25.8%. This compares to US$123 billion in imports from Africa, which grew by just 5.4%. Such a rising trade deficit between Africa and its largest sovereign trade partner points to the timeliness of new China policies that support African exports to China.

Beyond potential for trade facilitation and diplomacy, at a time of trade rivalry between the great powers, what might the change mean?

Based on years of study of China-Africa trade relations, I argue that there will be two probable main effects – one positive, one negative.

First, on the positive side, zero tariffs could provide incentives for cross-country export cooperation within Africa. On the negative, it risks creating conditions in which Africa’s stronger economies capture the most gain at the expense of weaker economies.

The existing regime

China’s Africa-specific trade preferences have evolved through the Forum on China-Africa Cooperation, established in 2000. China’s own global trade integration since its accession to the World Trade Organization in 2001 has also evolved.

Since 2005, African least developed countries have enjoyed zero-tariff access to China across 100% of tariff lines. Least developed countries are low-income countries confronting severe structural impediments to sustainable development. They are highly vulnerable to economic and environmental shocks and have low levels of human capital.

This policy restricted zero-tariff trade access to around 33 countries (subject to change owing to income growth and diplomatic recognition of Beijing). Africa’s middle-income exporters were excluded from the trade preferences.

South Africa, for example, continued to face tariffs on most exports, including fruits, wine and processed foods. Many were between 10% and 25%.

A handful of research papers have explored earlier Chinese trade preferences for Africa. For example, policy researcher and economist Adam Minson estimated that the least developed country tariff-free arrangements of 2005 would bring some countries as little as an additional US$100,000 annually.

My own PhD research found that by 2009 these preferential trade policies had not had any significant impact on exports. More recently, economists Zhina Sun and Ehizuelen Michael Mitchell Omoruyi found that the existing zero-tariff policy had promoted diversification of manufacturing exports to China and of regional trade. But there had been little effect on agriculture and mining export diversification.

One recurring recommendation has been to expand equal tariff treatment across African regional blocs. These include the East African Community, Southern African Customs Union and the Economic Community of West African States.

This could lead to production for export being organised regionally rather than distorted or even hampered by tariff differentials.

The reforms announced by Xi in February are a shift in this direction.

An incentive to co-operate?

By extending zero tariffs to almost all African countries, China has neutralised an element of distortion in its earlier tariff policy. When only some countries enjoyed tariff-free export benefits, investors and producers had incentives to locate export production in least developed countries to secure tariff-free access.

This worked some of the time, but not all the time. The reason for this is that least developed countries find it difficult to become exporters because they face inhibiting barriers to trade in general. Examples include unreliable electricity and poor infrastructure.

The zero tariff will put least developed countries at a disadvantage as they will lose the “special status” afforded them in the old regime. But the change could open another door. Production decisions can now take advantage of existing and potential cross-country and intra-regional supply chains based on comparative advantage – in place of being located where export tariffs were smallest.

Also, lowering tariffs for more developed African economies may enable African entrepreneurs to work across borders to engage in trade without facing different trade barriers by locality. That in turn may support Africa’s own agenda of trade integration.

To boost trade, China has also signalled it will expand trade facilitation measures. This includes upgraded “green lanes” for African imports. Prospective examples include:

faster customs clearance
streamlined phytosanitary procedures (rules governing food safety). An example would be setting up a clear set of criteria that enable an approved exporter, say of Kenyan avocados, to enjoy pre-approval for customs clearance.
greater investments in training and trade-related logistics.

China has also set up a dedicated China-Africa trade facilitation hub in Changsha, the capital of Hunan province. The aim is to have a central point of trade-related expertise and industries, making it easier for African and Chinese firms do business.

The risk of uneven gains

There is a risk that the new tariff regime will mean that production for export will concentrate in more developed countries, such as South Africa, Morocco and Kenya. These economies are better positioned to expand exports when it comes into effect.

In contrast, least developed countries will continue to struggle with:

constructing efficient trade-related infrastructure like telecommunications, electricity and port connectivity
production at export scale
reaching trade-related compliance standards such as the necessary fruit sizes and colour consistency.

China’s policy change calls for Africa’s frontier exporters to China to build trade-related supply chains across African borders to garner the scale and competitiveness to expand their own – soon tariff-free – exports to China. In turn, this would reduce the burden on least developed countries to need to export directly to China. Instead, they would only need to join regional trade supply chains.

Ideally within African sub-regions this could develop into a new incentive to create trade-related value chains.

The potential for equalisation

The May Day tariff reforms are a positive in removing formal tariff barriers at a time when tariffs are going up, led by the United States. This change simplifies incentives and eliminates structural asymmetries in China’s Africa trade regime.

Tariffs, however, are seldom the main constraint for African industrial transformation and export hopes. On top of this, uncertainty is complicating the global trade environment.

Nonetheless, these reforms are a step towards fostering sub-regional supply chains if African countries coordinate production strategies.

Lauren Johnston is affiliated with the AustChina Institute and South African Institute of International Affairs.

– ref. China’s new tariff-free regime for Africa: the potential upside and downside – https://theconversation.com/chinas-new-tariff-free-regime-for-africa-the-potential-upside-and-downside-277247

March 12, 2026

Cracking the code: How a “prediction machine” is resurrecting the Singapore Stone

Source: The Conversation – Indonesia – By Francesco Perono Cacciafoco, Associate Professor in Linguistics, Xi’an Jiaotong-Liverpool University

Several years ago, my linguistic research team and I began developing a computational tool we call ‘Read-y Grammarian’. Our goal was to reconstruct the highly fragmentary text of the Singapore Stone, a relic from the 10th to 14th centuries that features an undeciphered script similar to Kawi.

The software uses a specialised algorithm that applies digital philology (the study of oral and written texts) and epigraphy (the study of written matter recorded on hard or durable material) techniques to analyse ancient inscriptions.

We faced several setbacks while developing ‘Read-y Grammarian’ over the years. However, thanks to our persistence, the system is finally complete and fully operational.

Originally implemented for the Singapore Stone, ‘Read-y Grammarian’ can be used to reconstruct any fragmentary text. Its adaptive framework allows it to restore a wide array of damaged historical records — including manuscripts and papyri — with a few simple adjustments.

This flexibility makes the tool a powerful new ally for researchers looking to piece together the missing fragments of human history.

About the Stone

First recorded by the British in 1819 at the Singapore River’s mouth, the sandstone monolith was later demolished in 1843 to clear space for building projects. The roughly three-metre-square slab was largely destroyed, leaving only three surviving fragments.

After researchers sent those fragments to the Royal Asiatic Society’s Museum in Calcutta for study, their trail went cold. Their fate remained undocumented for decades until 1918, when — as far as records show — the institution returned only a single piece to what was then the Raffles Museum of Singapore.

Drawings of the fragments of the Singapore Stone — Singapore Stone’s fragments.
https://www.mdpi.com/journal/histories, CC BY

The Stone originally bore an inscription spanning roughly 50 lines, but its full text has been lost. All that remains are a handful of rough sketches made before its destruction, along with copies of the three fragments recovered after 1843 and the single original fragment that still exists.

The inscription remains a major puzzle. Its script resembles regional writing systems like the Javanese Kawi, but actually it doesn’t match any known writing system found on Earth.

Because no one has been able to read the Stone yet, it remains undeciphered.

The monument’s turbulent history, coupled with the complex and unique nature of its script, has fuelled its myth over the centuries. This has turned the artefact into one of the most intriguing challenges for scholars.

Alongside legendary puzzles like the Phaistos Disc and Linear A, the Singapore Stone remains one of History’s great unsolved codes.

Some link it to the legendary strongman Badang and the sprawling Majapahit Empire. Yet, until the conundrum is cracked, all connections — including those with ancient India or Java’s influence — remain speculative.

Decoding the void

Among other computational methods, ‘Read-y Grammarian’ works by digitising the inscription and assigning a unique alphanumeric (composed of both letters and numerals) code to every attested character. By tracking the exact position and line of every symbol, the algorithm identifies gaps in the text and reconstructs the likely original layout line by line.

It then applies frequency analysis and statistical and mathematical calculations — based on the linguistic patterns found in human languages — to predict which characters may have filled the missing spaces. This way, ‘Read-y Grammarian’ acts like a ‘prediction machine’, analysing the text step by step and converting its alphanumeric outputs back into actual characters.

We can also adjust specific settings in the system. For example, we can tweak the syntax (grammar rules and word order) of a reference language or language family — such asJavanese or Austronesian — or adjust the related morphology (the internal structure of words and how they are formed).

The algorithm then generates different possible versions of the text and our research team reviews these versions to determine which ones make the most sense linguistically.

This approach allows us to map phonemes (distinct units of sound that distinguish one word from another) to every character in the text, helping us identify possible words. It significantly streamlines the comparative process, letting scholars test the script against a variety of candidate languages to find a possible match.

Sample of the restoration of two Singapore Stone's characters — An example of Singapore Stone’s character restoration.
https://www.mdpi.com/journal/information, CC BY

What we know so far

Our ultimate goal is to solve the mystery of the elusive inscription. A text can be considered truly deciphered only when it can be read and understood in full.

Identifying an exact language will take time. However, we have already reached an important breakthrough: after centuries of silence, we have reconstructed several plausible versions of a complete text. This is a significant achievement, because the monolith itself was almost entirely destroyed. Reconstructing the original inscription would have been impossible without our custom algorithm.

Moreover, we are currently developing a more sophisticated model to expand the capabilities of ‘Read-y Grammarian’. The upgrade will allow us to generate systematic transcriptions at a much faster rate and in greater numbers. It will also incorporate advanced features, such as elements of historical phonology (the study of how sound systems change and evolve over time), to further refine the results.

A work in progress

Deciphering the Singapore Stone has proven extremely difficult, primarily because so little of the inscription survives. The fragments are too small to support reliable frequency analysis — assessing how often specific symbols appear in a text — or statistical studies.

Yet, pattern-recognition methods are the core tools of cryptanalysis (the art of cracking codes and ciphers), and they require far more data than the highly damaged epigraph can currently provide.

To break the deadlock, we must first focus on consistently reconstructing the full inscription. By restoring the text piece by piece and line by line, we can finally view the result as a complete composition.

Though this is not the same as actually reading the inscription, rebuilding the Stone’s original contents gives us the foundation we need to analyse the structure of its text.

Before we can interpret and decipher its fragmentary remains, this crucial first step will pave the way for decoding its writing system and finally identifying the unknown language hidden within.

Francesco Perono Cacciafoco received funding from Xi’an Jiaotong-Liverpool University (XJTLU): SURF Grant “Unveiling the Secrets of the Singapore Stone: A Digital Philology Investigation” – Grant Number: SURF-2025-0032, School of Humanities and Social Sciences (HSS), Xi’an Jiaotong-Liverpool University (XJTLU), Suzhou (Jiangsu), China, 2025.

– ref. Cracking the code: How a “prediction machine” is resurrecting the Singapore Stone – https://theconversation.com/cracking-the-code-how-a-prediction-machine-is-resurrecting-the-singapore-stone-276642

March 11, 2026

Mandelson files released at sensitive time for UK relations with Donald Trump

Source: The Conversation – UK – By Christopher Featherstone, Associate Lecturer, Department of Politics, University of York

The release of the “Mandelson files” comes at a difficult moment in relations between the US and UK. It is unlikely to ease tensions.

The UK government has submitted to pressure from MPs to disclose files relating to the hiring and vetting of Peter Mandelson as UK ambassador to the US. Questions have been raised about how much officials, including the prime minister, Keir Starmer, knew about Mandelson’s friendship with paedophile Jeffrey Epstein after his conviction for sex offences in 2008.

The key takeaway from the release doesn’t relate to the US president, Donald Trump. This is that Mandelson tried to negotiate a severance package worth £547,201 after being asked to leave his post in Washington. He ended up getting £75,000. But there are details in the documents that will not be welcomed by the US, and the nature of the release will be of concern to a White House already under pressure for its own approach to Epstein.

Trump has already spent recent weeks publicly criticising Starmer for failing to support him on Iran, saying Starmer is no “Winston Churchill”. The release of these files may well lend further opportunity for Trump to hit out.

Lack of control

The questions about how much Starmer knew about Mandelson and Epstein arose in the first place after the US government partially released the Epstein files in January. These included email exchanges between Mandelson and Epstein revealing a relationship that extended long after the latter’s conviction. They have also led to a police investigation over communications made between the two men while Mandelson was a government minister. These allegedly relate to sensitive government information rather than anything relating sex offences.

Trump will not like the fact that this release has brought the Epstein files back into the spotlight – and particularly that it is happening in circumstances beyond his control.

Trump has repeatedly called for the Department of Justice to “move on” from this story, having faced questions about his own relationship with Epstein. He recently attacked CNN journalist Kaitlan Collins for not smiling as she asked him questions about the Epstein files, in a clear attempt to distract public attention.

There is a risk that the Mandelson document release will renew pressure on Trump to release the full cache of documents held by the US government – and that he will seek to divert attention by lashing out again at Starmer.

Donald Trump and Keir Starmer talking. — Trump and Starmer, pictured in September 2025.
Number 10/Flickr, CC BY

Unsurprisingly, given that many of these released documents were written for private consumption, they contain some comments that may be embarrassing for the authors and subjects.

In the documents, we can see the UK government reviewed public comments Mandelson made condemning Trump policies prior to his appointment as ambassador, apparently to consider whether they were a problem during the vetting process.

When speaking to students in Hong Kong, Mandelson said: “it’s also necessary to recognise Mr Trump’s behaviour for what it is: he is a bully and mercantilist who thinks that the US will gain in trade only when others are losing”. Trump will likely be annoyed by this attack on his treasured “tariffs” policy.

Crucially, given that Starmer appointed Mandelson despite these comments, these documents also show that the UK government did not object to Mandelson’s view.

London v Washington

The release from the UK will fuel a debate that has begun on the difference between how London and Washington have both responded to the the revelations in the Epstein files. The Trump administration continues to refuse to release its own files in full – and continues to be accused of covering up Trump’s relationship with Epstein.

The UK government has demonstrated that it is willing to fire people over their relationships with Epstein and that it won’t protect them from police investigation. Now it has shown willingness to release files showing how much the government knew about these relations. This is of course not the full release of files and Starmer insists several key items can’t be released because they are part of an ongoing police investigation, but it still leaves space for criticism of the US.

Trump and his administration will have been hoping that media attention would move on, focusing on the controversial airstrikes on Iran, or continuing ICE raids across US cities. It will not welcome inevitable comparisons between its unwillingness to act on revelations from the Epstein files – or to keep releasing more files – and the UK government’s decision to do both.

Crucially, US government officials will be watching for further document releases to see if this situation gets any worse.

Christopher Featherstone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Mandelson files released at sensitive time for UK relations with Donald Trump – https://theconversation.com/mandelson-files-released-at-sensitive-time-for-uk-relations-with-donald-trump-278129

March 11, 2026

Black female footballers are praised for their strength, white players for their intelligence: what our study shows

Source: The Conversation – UK – By Paul Ian Campbell, Associate Professor in Sociology (Race and Inclusion in sport and in education), University of Leicester

For black female professional footballers, racism has become a distressingly regular part of the game. Earlier this year, England defender Jess Carter told the BBC that the racist abuse she received online during the 2025 Euros made her fearful to leave her hotel room.

Black sportswomen routinely deal with racial abuse from fans and teammates. But less discussed is how their bodies, emotions and on-pitch performances are spoken about by sports commentators. It’s not just negative comments, either. Clear racial stereotypes emerge when comparing positive comments about black players with those about white players. Our 2025 study examines commentary during the 2019 Fifa Women’s World Cup, does just that.

We analysed 2,905 comments of praise given to footballers during 80 hours of BBC and ITV coverage, across all 52 matches at the tournament. We found that white women were more frequently praised for their intelligence and technical proficiency, while black women received the most praise for their perceived physical prowess and natural athleticism.

White players were more frequently praised skills learned through practice, such as having a “lovely technique” (49.4% of all comments about white players), followed by physical (20.3%), character (16.2%), cognitive (10.8%) and natural (3.3%) abilities.

Black players received almost double the amount of praise for their physical prowess (39.5% of comments about black players) and natural abilities (5.8%). They received notably fewer praise comments for learned skills (36.8%), as well as lower amounts of praise for character (11.9%) and cognitive attributes (6.0%).

These differences were especially noticeable in the coverage of national teams from white-majority countries that had more than two black players in their starting squad. England’s two non-white players (accounting for 18.2% of the team) received 50% of all of their team’s praise for natural attributes. These were comments praising qualities that were perceived to be innate, such as being a “magician” on the pitch. England’s visibly white players (81.8% of the team) received almost the entire amount of the praise given to the whole team for cognitive attributes (96%).

Jess Carter discusses her experiences with racism.

France’s black players, who accounted for 43% of team, received 90% and 85% of the team’s total praise for natural and physical attributes, respectively. White French players, who similarly constituted 43% of the playing squad, received 68% of the teams’ total praise for intelligence.

We also found that black female players were more likely to be described as being angry and emotionally unstable during matches. Nigeria’s forward Desire Oparanozie was described as “playing with a bit of anger” and England’s Nikita Parris was said to be unable to maintain her composure, with a tendency to frequently “make her feelings known”.

Their white teammates, on the other hand, were described as calm and composed.
During the England v Cameroon match, commentators praised the almost entirely white England team for keeping their composure and not “reacting” to “unseemly things going on the pitch” by the African players.

The harm of misogynoir

Black women experience a unique form of discrimination called misogynoir. It is different to the exclusions faced by white women and the racism experienced by black men. It is the result of a combination of the misogyny directed at their gender and the anti-black racism directed at their race.

Sport media is a powerful site where the gender and racial stereotypes that exist in society are replicated. It has a long history of portraying black sportswomen as powerful, hyper-masculine and angry.

Studies have shown that black sportswomen are frequently stereotyped as unfeminine, masculine and strong, lacking intelligence, emotionally unstable, inherently angry and overly aggressive. Conversely, white women are seen to embody Eurocentric beauty standards and accepted feminine ideals, such as notions of purity, grace, emotional stoicism and delicacy.

These stereotypes have real-life consequences for black sportswomen. Some footballers have gone so far as to change how they play so that they are not seen as angry or masculine, but just as women who play the game they love. For example, ex-England player Anita Asante explained:

You have to check yourself to make sure people don’t view you in that light. Maybe on that particular day in a training session, I am that sassy person, or I am that competitive person that comes across a bit more feisty – but because there is an association with being a black woman and having that energy and boldness is not always seen a positive thing, [so] I might refrain from being that person and contain more of my emotions.

Evidence shows that misogynoir can influence the career opportunities that are afforded to black women more generally. A recent US study connected racism to higher levels of stress and to higher mortality rates.

Unless, meaningful action is taken by broadcasters to change the practice of commentary through tallying exercises like our research, then commentators might be unwittingly contributing to the racial stereotypes that cause psychological and physiological harm to the same superstars that they idolise and praise.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Black female footballers are praised for their strength, white players for their intelligence: what our study shows – https://theconversation.com/black-female-footballers-are-praised-for-their-strength-white-players-for-their-intelligence-what-our-study-shows-276993

March 11, 2026

Congress still has ways to throttle back Trump’s war with Iran – and to ask questions

Source: The Conversation – USA – By SoRelle Wyckoff Gaynor, Assistant Professor of Public Policy and Politics, University of Virginia

What power does the U.S. Congress have over the president’s war in Iran? Douglas Rissing, iStock/Getty Images Plus

Despite the scale of its military assault on Iran, the Trump administration’s reasons for entering into war have been inconsistent and vague, from regime change to the destruction of nuclear weapons, preempting military action by Israel, or the more chilling decree of following “God’s divine plan.”

Politicians, pundits and even social media users have been quick to point out the contradictions of these justifications – regime change is impossible from the air, especially when you kill the alternatives, and weren’t those nuclear weapons already destroyed?

But the “why” for entering into war matters beyond scoring political points.

Why, and how, a president engages in military action has serious implications for the constitutional authority of any wartime action and, specifically, whether Congress has any hope of checking the warmaking of a president.

War powers and ‘imminent threats’

Under Article 1, Section 8, of the U.S. Constitution, only Congress has the authority to declare war.

One way around this, as the Trump administration and congressional Republicans have half-heartedly attempted, is to avoid calling this conflict a “war.” The messaging didn’t stick. In fact, President Donald Trump has already used the term repeatedly.

Secretary of State Marco Rubio asserted that the U.S. military action in Iran was prompted by an ‘imminent threat.’

The more viable option for sidestepping the need to have Congress declare a war is for the president to claim authority under the War Powers Resolution of 1973, which grants a president the power to involve the armed forced in “hostilities” or “potential hostilities” without congressional approval only under extraordinary conditions of “imminent threat.”

At least one member of the administration appears to understand this nuance: Secretary of State Marco Rubio – notably, a former member of Congress himself. Rubio used the specific terminology “imminent threat” when discussing why the Trump administration began the bombing.

Absent a truly imminent threat, the president is required by the resolution to “consult regularly” with Congress before and after engaging in military action. Importantly, the military action is limited to 60 days, during which the president must “report to the Congress periodically” with updates to keep the legislative branch informed.

After 60 days, the president must, the resolution says, “terminate any use of United States Armed Forces.” If a president wants to wage a war longer than that, that requires an additional declaration by Congress. Such a declaration would require votes similar to a bill being passed.

In 2002, for example, after initiating a “war on terror,” President George W. Bush eventually turned to Congress to pass the Authorization for the Use of Military Force Against Iraq. This permitted Bush to send troops into Iraq and further pursue a war that would last a decade.

In today’s case, by claiming that the Iranian regime was posing an imminent threat to the United States, the president can more easily circumvent congressional approval for military action and then turn to Congress after the fact if further action is needed.

As we recently discussed on our podcast about Congress, “Highway to Hill,” Congress has been continually ceding its power to the executive branch for decades. Deflection on military authority goes back even further: Congress hasn’t formally declared war since World War II – yes, despite involvement in Korea, Vietnam, Afghanistan and many other places. But the Constitution doesn’t mince words on who’s responsible for entering the U.S. into war: Congress.

And how this war is ultimately framed by the White House has implications for the types of oversight Congress can perform to limit or curtail military action.

The limited powers of the war powers resolution

Congress, seemingly caught off guard by the Trump administration’s actions in Iran, has responded in a few ways. Perhaps unsurprisingly, responses have fallen largely along party lines.

Following the initial bombings, U.S. Sen. Tim Kaine, a Democrat from Virginia, introduced a war powers resolution to prevent further military action in Iran. In the House, U.S. Reps. Ro Khanna, a California Democrat, and Thomas Massie, a Republican from Kentucky, introduced a similar bipartisan resolution. The votes failed in both chambers despite overwhelming support from Democrats.

On the Republican side, Rubio’s explanation for the military action seemed to appease many key members of Congress. Senate Majority Leader John Thune, a South Dakota Republican, claimed the president had the authority to move forward with military action in Iran.

Speaker of the House Mike Johnson, a Louisiana Republican, said that any congressional attempt to limit the president’s warmaking power would be “frightening” and “dangerous.”

Public accountability in congressional hearings

A large hearing room in a government building, with men lined up behind a long talbe in the front, and witnesses and the public on the other side. — Oversight at work in Congress, as the Senate Foreign Relations Committee on Feb. 10, 1966, holds one of its many hearings on the Vietnam war. George Kennan, former ambassador to Moscow, is at the witness table.
Henry Griffin, AP file photo

But Congress has two more traditional and frequently used oversight tools at its disposal: oversight hearings and the power of the purse.

Oversight hearings provide members of Congress an opportunity to not only question and investigate the executive branch’s activity, but also to provide their constituents with this fact-finding work and draw attention to policy issues. As some recent oversight hearings indicate, these can also be opportunities for partisan jabs and “made for TV” moments.

But there is evidence that they produce results.

Following tense oversight hearings on excessive spending in the Department of Homeland Security, Secretary Kristi Noem was fired from her position in early March 2026.

In the 1970s, the Church Committee – named for its formidable chair, U.S. Sen. Frank Church of Idaho – held extensive hearings that included eye-opening testimony about clandestine U.S. intelligence activities abroad and domestically. The Church Committee recommended, and Congress subsequently enacted, dozens of sweeping reforms to foreign intelligence collection activities, as well as restraints on future efforts by the U.S. government to assassinate people.

Although the Trump administration has provided closed-door briefings to members of Congress, Democratic senators are asking for more. They are calling for Department of Defense Secretary Pete Hegseth and Secretary of State Rubio to come before congressional committees to explain their reasoning and plans for the Iran war.

Not only do oversight hearings provide members of Congress with an opportunity to investigate and question an administration’s actions, but they bring that discussion to the public. This transparency provides constituents with information about how their tax dollars are being spent, what their members of Congress think, and may even sway public opinion.

Power of the purse

But perhaps the most powerful tool that Congress has is its power of the purse, outlined in Article 1 of the Constitution.

Military actions in Iran are already costing an estimated US$1 billion a day, or as U.S. Rep. Tom Cole of Oklahoma, the Republican House Appropriations Committee chair, put it: “a lot.”

As the war drags on, the Trump administration will need more money – money that only Congress can dole out. Unlike war powers resolutions, which in this case would limit military action after the fact, new spending cannot occur until Congress writes and passes legislation appropriating additional funds.

But this would constitute a blank check for a foreign war. And that might be too much to ask of members of Congress in both parties, particularly as the U.S. faces a historic deficit and cuts to safety net programs.

And as public opinion on both military action in Iran and the state of the economy continues to sour, a vote for more military spending might well overtax any remaining goodwill of voters and members of Congress alike.

In fact, the political pressure on Congress to put its foot down could become so immense that lawmakers may have to do something – like their job.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Congress still has ways to throttle back Trump’s war with Iran – and to ask questions – https://theconversation.com/congress-still-has-ways-to-throttle-back-trumps-war-with-iran-and-to-ask-questions-277813

March 11, 2026

How we turned plastic waste into vinegar: A sunlight-powered breakthrough

Source: The Conversation – Canada – By Yimin Wu, Associate Professor, Tang Family Chair in New Energy Materials and Sustainability, University of Waterloo

Hundreds of millions of tonnes of plastic are produced globally every year. New research shows how that waste can be turned into something useful. (Unsplash/Nick Fewings)

Plastic is one of the most durable materials humans have ever made. That durability has made it indispensable in medicine, food packaging and transport. But it’s also created one of the defining environmental problems we have faced.

Hundreds of millions of tonnes of plastic are produced globally every year. Much of it ends up in landfills, incinerators or the natural environment, where it can persist for centuries.

The methods we have for getting rid of plastic pollution have their downsides. Putting it in landfills means chemicals and microplastics can seep into the surrounding environment.

Burning it releases harmful fumes and toxins. Mechanical recycling often downgrades plastics into lower-value products, while chemical recycling typically requires high temperatures, high pressures and large amounts of energy.

Colleagues and I recently published research that explores a very different possibility: using sunlight and an iron-based catalyst to convert common plastic waste directly into acetic acid — the key component of vinegar and an important industrial chemical.

Instead of treating plastic purely as waste, our research shows that it can be transformed into something useful under mild conditions.

Learning from a wood-rotting fungus

The inspiration for our research came from nature. The white-rot fungus (Phanerochaete chrysosporium) is famous for its ability to break down lignin, one of the toughest polymers found in wood. It does this using enzymes that generate highly reactive chemical species capable of dismantling complex carbon structures.

We wondered whether a synthetic material could mimic this strategy.

The catalyst we designed is iron-doped carbon nitride, a semiconductor that absorbs visible light. We then anchored individual iron atoms, creating what scientists call a single-atom catalyst.

Rather than forming nanoparticles, each iron atom is isolated and embedded within the carbon nitride structure. This atomic precision is crucial. Each iron atom behaves like an active site in a natural enzyme, maximizing efficiency while maintaining stability.

A two-step reaction powered by light

The system works through a cascade of light-driven reactions.

Under sunlight and in the presence of hydrogen peroxide, the iron sites activate the peroxide to generate highly reactive hydroxyl radicals. A radical is an atom, molecule or ion that has at least one unpaired electron. This makes them highly chemically reactive.

These radicals attack the long carbon chains that make up plastics, like polyethylene (used in plastic bags), polypropylene (food containers), PET (drink bottles) and even PVC (pipes and packaging).

The polymers are progressively oxidized and broken down into smaller molecules, eventually forming carbon dioxide (CO₂).

Rather than allowing this CO₂ to escape, the same catalyst then performs a second job: it uses sunlight to reduce the CO₂ into acetic acid. In other words, the carbon in plastic waste is first oxidized and then re-assembled into a new, valuable molecule.

Essentially, this approach breaks down plastic and converts the resulting carbon into a commodity chemical in a single system. This distinguishes it from most existing recycling technologies.

Why acetic acid?

Acetic acid is best known as the sour component of vinegar, but it is also a major industrial feedstock. It is used to produce adhesives, coatings, solvents, synthetic fibres and pharmaceuticals.

Global demand runs into the millions of tonnes each year, representing a multi-billion-dollar market.

Currently, most acetic acid is produced through an energy-intensive processes process called methanol carbonylation, whereby methanol is reacted with carbon monoxide at high temperatures.

Converting waste plastic into acetic acid offers a potential circular pathway: instead of extracting new carbon, we reuse carbon already present in discarded materials.

In our experiments, the system produced acetic acid at rates comparably favourable with other reported light-driven plastic conversion methods. When we enhanced light utilization inside the reactor, the production rate increased substantially.

Importantly, the reaction operated at room temperature and normal atmospheric pressure. That contrasts with many chemical recycling methods that require heating plastics to several hundred degrees Celsius.

Handling real-world plastic

Laboratory studies often focus on pure, single plastic types. But real waste streams are mixed and contaminated. We therefore tested different common plastics individually, as well as mixtures.

Our catalyst was able to convert several major commodity plastics. Interestingly, PVC showed particularly strong performance. We believe chlorine released during its breakdown may generate additional reactive radicals, accelerating degradation.

The iron atoms remained atomically dispersed after repeated use, indicating good stability. This matters because catalyst degradation or metal leaching can undermine both performance and environmental safety.

The system does rely on added hydrogen peroxide, which is consumed during the reaction. While hydrogen peroxide decomposes into water and oxygen and is considered relatively benign, future work will need to address how it can be supplied sustainably at scale.

From concept to practice

Scaling up any new chemical process presents challenges. Light penetration, reactor design and the variability of waste plastic feedstocks all affect efficiency. Additives in commercial plastics — such as stabilizers, pigments and plasticizers — can also influence reaction outcomes.

To explore feasibility, we conducted a preliminary techno-economic assessment. This is a way of analyzing the potential economic benefits of an industrial process or product.

While further optimization is required, our analysis suggests that coupling waste cleanup with the production of a valuable chemical could help offset costs — particularly when environmental benefits are taken into account.

More broadly, this work illustrates the power of single-atom catalysts and bio-inspired design. By mimicking the way enzymes control reactivity at precise metal centres, we can achieve complex chemical transformations under mild conditions using sunlight as the energy source.

Rethinking plastic’s life cycle

The problem of plastic pollution will not be solved by a single technology. Reducing unnecessary plastic use, improving product design and strengthening recycling systems are all essential.

Transforming plastic waste into useful chemicals offers a complementary strategy. It reframes plastic not only as an environmental burden but also as a carbon resource.

If we can harness sunlight to drive these transformations efficiently and at scale, yesterday’s discarded packaging could become tomorrow’s industrial feedstock.

The challenge now is to translate our laboratory advances into robust, scalable systems. If successful, it would mark a step toward a more circular economy — one where waste is not the end of the story, but the beginning of a new one.

Yimin Wu receives funding from Tang Family Chair in New Energy Materials and Sustainability, Natural Sciences and Engineering Research Council of Canada, the seed funding from the Water Institute (WI), Waterloo Institute for Nanotechnology (WIN) at the University of Waterloo.

– ref. How we turned plastic waste into vinegar: A sunlight-powered breakthrough – https://theconversation.com/how-we-turned-plastic-waste-into-vinegar-a-sunlight-powered-breakthrough-276735