Hotter Days, Fewer Boys? How Climate Change Is Quietly Reshaping Birth

The Malaria Paradox

On World Malaria Day, the spotlight turns once again to one of the world’s oldest and deadliest diseases. This year, the story feels different. For decades, the malaria vaccine was seen as the breakthrough the world was waiting for. Now it’s here. So why does the fight against malaria still feel unfinished? In this episode, I speak with Photini Sinnis, a professor at the Johns Hopkins Bloomberg School of Public Health and a leading expert on how malaria infection begins in the body. We unpack what the arrival of malaria vaccines really means—and what it doesn’t. Why these vaccines were never meant to be a “magic bullet.” Why bed nets, drugs, and vector control still matter. And why combining tools, rather than relying on one breakthrough, may be the only realistic path forward. We also go deeper into the science: the hidden complexity of the malaria parasite, the push toward multi-stage vaccines, and the knowledge gaps that still define this field. Along the way, we confront a harder truth—why global health innovation doesn’t always move at the same speed for every disease. There is real progress. There is renewed optimism. But there is no simple solution. This is the malaria paradox: more tools than ever before, yet a fight that is far from over.

Replacing Forever Chemicals: The Hidden Toxins Already in Your Body

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.

Cancer Care Amid Geopolitical Crises

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.

A Cosmic Laser from Eight Billion Years Ago

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 [https://www.nature.com/articles/d44148-026-00055-6]

Hotter Days, Fewer Boys? How Climate Change Is Quietly Reshaping Birth

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 [https://www.pnas.org/doi/10.1073/pnas.2422625123] 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.