Paul Talks Science

What if some of the most persistent pollutants on Earth are already inside us?

In this episode of Paul Talks Science, we explore the growing global concern around PFAS, widely known as forever chemicals—a group of man-made substances used in everyday products like non-stick cookware, waterproof clothing, food packaging, and firefighting foams. These chemicals are called “forever” because they don’t easily break down in the environment or in the human body. Over time, they accumulate in water, soil, wildlife—and increasingly, in people.

As policymakers debate how to regulate these substances, lawmakers including Betty McCollum and Dick Durbin have renewed efforts to phase out many non-essential uses of PFAS and hold polluters accountable. But regulation alone may not solve the problem.

On a bright, sunny day in Massachusetts, I visited the Toxics Use Reduction Institute (TURI), where scientists are working on a crucial question: how do we replace PFAS in the products we rely on every day?

During my visit, I spoke with TURI scientists Greg and Gabriel about why PFAS became so widespread, the challenges of cleaning them up once they enter the environment, and why developing safer alternatives could be one of the fastest and most effective solutions.

In this conversation, we unpack:

• What forever chemicals are and why they’re so difficult to remove
• How PFAS end up in everyday products and in our bodies
• The growing political and regulatory pressure to phase them out
• Why some scientists believe replacement—not destruction—may be the smarter path forward

At a time when global headlines are dominated by geopolitical tensions and conflict, the long-term challenge of chemical pollution can easily fade from view. But the decisions we make about PFAS today could shape environmental and public health for decades to come.

🎧 Listen in as we explore the science, policy, and innovation behind the push to replace forever chemicals.

In this episode of Paul Talks Science, we explore the hidden toll of conflict on cancer patients and health systems. I speak with Professor Mark Lawler, Co-Chair of the European Cancer Organisation’s Emergencies and Crises Network, about how wars and geopolitical crises disrupt access to life-saving treatments, from chemotherapy to radiotherapy, and why low- and middle-income countries are especially vulnerable.We discuss the ripple effects of displaced patients, fragile supply chains, and delayed treatments, and hear why global preparedness and international cooperation are critical to protecting cancer care in times of crisis. From Ukraine to Africa and the Middle East, this episode sheds light on a growing humanitarian and health challenge that often goes unnoticed.Tune in to learn why cancer care cannot be sidelined—even in the midst of conflict.

What happens when two galaxies collide?

In this episode, science journalist Paul Adepoju speaks with astronomers Thato Manamela and Roger Deane about the discovery of one of the most distant and powerful cosmic lasers — a gigamaser — ever detected.

Using the MeerKAT radio telescope in South Africa, the team identified an extraordinary signal coming from a pair of merging galaxies more than eight billion light-years away. These rare natural lasers, known as megamasers, form under extreme conditions and can act as cosmic beacons, revealing intense star formation, hidden galaxy mergers, and possibly even pairs of supermassive black holes.

The discovery offers a glimpse into how galaxies evolved in the early universe and highlights the growing role of African-led astronomy ahead of the Square Kilometre Array (SKA) — the world’s largest radio telescope.

Adepoju also discusses the story behind the research and the reporting process behind his Nature Africa article on the discovery.

🔭 In this episode:

• What cosmic megamasers and gigamasers are

• Why galaxy collisions create powerful radio signals

• How the MeerKAT telescope detected this rare phenomenon

• What this discovery reveals about the early universe

• Why Africa is becoming a global hub for radio astronomy

📖 Read the full story in Nature Africa:
https://www.nature.com/articles/d44148-026-00055-6

In this episode of Paul Talks Science, Paul sits down with Dr. Jasmin Abdel Ghany to unpack groundbreaking new research showing that rising temperatures don’t just affect the planet — they affect who we are. A major study published in Proceedings of the National Academy of Sciences reveals that exposure to heat during pregnancy is linked to shifts in the sex ratio at birth. By analysing more than five million births across 33 Sub-Saharan African countries and India, the team finds that temperatures above about 20 °C are consistently associated with fewer male births — but for strikingly different reasons in each region. In Sub-Saharan Africa, heat early in pregnancy may increase prenatal loss among male fetuses. In India, heat later in pregnancy appears to influence access to or use of sex-selective abortion, temporarily narrowing long-standing gender imbalances. Listeners and viewers will discover how climate stress can shape human reproduction biologically and behaviourally, and why these hidden effects matter for population health and gender balance as the world warms.

What if the largest structures in the Universe aren’t just expanding — but spinning?

In this episode, host Paul Adepoju explores one of the most intriguing recent developments in cosmology: evidence that a vast cosmic filament stretching tens of millions of light-years may be rotating. The conversation builds on Paul’s feature for Physics Magazine, originally developed as the winning pitch of the Quantum Pitch Competition — launched by Physics Magazine in partnership with Physics World to mark the International Year of Quantum Science and Technology. His article described how astronomers detected large-scale galactic motion using radiation produced by tiny quantum “spin flips” in hydrogen atoms. Read it here.

Drawing on that reporting and an in-depth interview with astrophysicist Dr. Madalina Tudorache, this episode examines how galaxies align along cosmic filaments, how neutral-hydrogen observations reveal coordinated motion, and why angular momentum at these scales is reshaping questions about galaxy formation and large-scale structure.

Along the way, we connect quantum-scale measurements — the 21-centimeter hydrogen transition — to observations of the cosmic web, discuss the role of South Africa’s MeerKAT telescope in enabling the discovery, and reflect on how global collaboration and African radio-astronomy infrastructure are influencing frontier astrophysics.

This episode unpacks the discovery, the physics behind it, and the broader story of how we come to understand motion across the Universe.

Antimicrobial resistance is often framed as a technical problem for scientists and policymakers. But the truth is far simpler — and far more unsettling: the choices made in clinics, pharmacies, farms, and homes every day are helping to decide whether life-saving medicines will still work in the future.

In this episode, we unpack why AMR isn’t just a laboratory or hospital issue, but a shared societal challenge. Drawing on expert insight and real-world experience, the conversation explores how misuse of antibiotics, gaps in regulation, weak infection prevention, and limited public awareness are accelerating resistance — especially in settings where access and oversight collide.

Crucially, the episode also looks forward. From community awareness and responsible prescribing to hygiene, sanitation, and people-centred primary health care, it examines what practical action can look like — not in theory, but in everyday life.

Because when antibiotics fail, it won’t just be health systems that feel it. It will be all of us.

My guest is Dr Ali Ahmed Yahaya, Team Leader of the Antimicrobial Resistance Unit at the World Health Organization African Regional Office.

Thank you for the journey in 2025, here is what will be the highlight of the new year 2026. Happy New Year.

Africa has the talent to power the world’s most advanced AI systems — so why is so much of that talent building elsewhere?

In this episode, we sit down with a postdoctoral researcher at a US Department of Energy national laboratory working at the intersection of artificial intelligence and high-performance computing. He breaks down what supercomputers actually do, why they matter for science and society, and how African researchers are already shaping global AI — often without the infrastructure to do so at home.

From childhood curiosity and mentorship in Nigeria to working with AI, IoT, and citizen science to improve food security, this conversation explores how local knowledge, not just massive computing power, can drive innovation. We unpack Africa’s strengths in human capital, the challenges of outdated curricula and weak systems, and what it will really take to tackle brain drain, reform education, and build technology ecosystems that work locally and compete globally.

This is a wide-ranging discussion on AI in Africa, supercomputing, education reform, agriculture, health systems, and the urgent need to create environments where African talent can thrive — at home.

What if the way we understand shape, space, and structure could help us see disease differently?

In this episode of Paul Talks Science, I sit down with South African mathematician Dr. Cerene Rathilal to explore topology, a branch of mathematics that asks what stays the same even when things are stretched, twisted, or transformed, and why those ideas now matter far beyond the chalkboard.

Cerene traces her journey into mathematics, from a childhood shaped by curiosity to the moment she realised that being good at maths was not the same as being told you could become a mathematician. We talk about the quiet ways society steers talented students away from pure mathematics, and what it means to choose a path that is not always visible or celebrated.

The conversation moves from theory to impact, as Cerene explains how topological data analysis is being explored in areas such as breast cancer diagnosis, helping researchers look at medical images and data in entirely new ways. We also discuss why Africa has a growing role to play in advanced mathematical research, and how global scientific spaces can create mobility, collaboration, and confidence for African scholars.

Beyond the mathematics, this episode is about representation, mentorship, and making space. Cerene shares why she founded a programme to support girls pursuing STEM careers in South Africa, and what it takes to turn personal experience into collective opportunity.

This is a conversation about mathematics as a way of seeing, science as a human endeavour, and why abstract ideas often shape the real world more than we realise.

In this episode, we follow the journey of Hannah, a young Ghanaian researcher whose relationship with mathematics completely transformed once she discovered where the equations finally led. From early confusion in abstract university courses to finding clarity through disease modelling, Hannah shares the moments, mentors, and opportunities that reshaped her understanding of what math can do — and who it is for.

She talks openly about the gaps in math education across Africa, the power of exposure, and the role supportive supervisors played in helping her find her footing in biomedical data science. We explore how mathematical skills are opening new frontiers in health, AI, and problem-solving on the continent, and why she believes Africa’s unique challenges also represent its greatest opportunities.

This is a conversation about seeing math differently, building confidence as a young researcher, and imagining a future where African mathematicians shape solutions for their own communities — and beyond.