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| Dmitriy Mazurov in Minotaur |
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| Dmitriy Mazurov in Minotaur |
Whales and dolphins inhabit some of the largest and seemingly most pristine environments on Earth, from tropical coastlines to Antarctic waters. Yet even they cannot escape PFAS – persistent “forever chemicals” that leak from our homes, factories and waterways into the sea.
Forever chemicals are the secret ingredients in our non-stick pans, waterproof jackets and stain-resistant carpets. These chemicals belong to a group of more than 1,400 compounds known as PFAS (per- and polyfluoroalkyl substances). They enter the environment through manufacturing waste, industrial runoff, wastewater treatment plants and firefighting foams. But once these chemicals escape our homes and factories, they become almost impossible to get rid of. Washed into waterways, they make their way to the sea.
Small organisms absorb them from the water, fish eat those organisms and larger predators eat the fish. At each step, the chemical load increases. As top predators, whales and dolphins can end up with very high levels in their bodies. Not even deep-diving species living and feeding far from humans are safe.
In our new research, we found PFAS concentrations in cetaceans have increased globally since 2000. Animals in the Pacific Ocean were the most contaminated, with humpback dolphins showing the highest PFAS concentrations.
These mammals are sentinels of ocean health. They sit high in the food web, live for many years and are exposed to pollution across large areas of the ocean. When whales and dolphins show signs of chemical exposure, it tells us something is wrong in the wider marine ecosystem.
Many of these chemicals have been in use for decades. Their sheer durability and ability to resist heat, oil and water make them very useful.
Scientists have grown increasingly concerned about them because they persist for decades and build up over time in our own bodies, as well as in wildlife and the broader environment.
The key concern is what these chemicals may be doing to the animals that accumulate them.
Research in humans and laboratory animals links PFAS to immune suppression, hormonal changes, reproductive problems and developmental effects. But we don’t yet have enough research to understand how different PFAS compounds and levels of exposure affect health.
Understanding these impacts in whales and dolphins is harder still. Marine mammals are long-lived, highly mobile and exposed to many human-made problems at once, from climate change to noise pollution to other contaminants.
Even so, there are warning signs. Some dolphin studies have reported changes in immune-related markers associated with PFAS exposure.
For humans, testing PFAS levels is usually done with a blood test. It is not as simple for whales and dolphins.
It is extremely difficult to take blood samples from large marine mammals in the wild. Scientists often rely on tissue samples from dead animals, particularly from the liver and kidney where many PFAS compounds tend to accumulate. These samples are analysed in specialised laboratories capable of detecting tiny concentrations of individual PFAS compounds.
This way, scientists have been measuring PFAS in whales and dolphins for decades. Each study added another piece to the puzzle, showing these chemicals were present in different species, populations and oceans.
Our study took a step back and looked at the global picture.
We compiled PFAS data from cetaceans worldwide, focusing on liver samples because they are the most commonly available tissue type, allowing us to compare studies across species and regions.
We found PFAS contamination differed substantially across species, location, sex, age and time.
The highest concentrations tended to be found in coastal dolphins and porpoises, suggesting animals living near urban and industrial areas face greater exposure.
Cetaceans in the Pacific had higher levels than other oceans. This is likely due to high industrial activity and the extent of historical PFAS production in coastal regions.
Female whales and dolphins can transfer forever chemicals during pregnancy and nursing. This means their calves can be exposed to concerning levels of PFAS at a very early age.
Males often end up with higher levels than females overall, as they cannot transfer these chemicals to their young.
There are some large gaps in the global dataset we collated, which means we don’t fully know the extent of PFAS contamination in cetaceans off India, Indonesia and parts of Africa.
While important questions remain about the effects of forever chemicals on whales and dolphins, the widespread contamination we observed is a real concern. We need to continue monitoring while strengthening regulations and working to reduce PFAS flows into the environment.
History shows global action on harmful chemicals works. After it became clear Earth’s protective ozone layer was being eaten away, nations agreed to phase out the chemicals responsible. The ozone layer is now recovering.
The European Union moved to ban some PFAS compounds 20 years ago. Our study found lower levels of some legacy PFAS compounds in the Mediterranean Sea, a pattern that may reflect the effects of regulation. This is positive, but not sufficient given overall PFAS levels in whales and dolphins have increased globally over time. The EU is now moving to better regulate this class of forever chemicals.
Forever chemicals are one of the defining pollution challenges of our time. The more we understand how these chemicals accumulate in whales and dolphins, the better equipped we will be to reduce future contamination and protect marine ecosystems.
What ends up in the ocean does not simply disappear. And neither do PFAS.
This article is based on collaborative research that also included Lavinia Stokes (University of Wollongong), Jesuina de Araujo (National Measurement Institute) and Gavin Stevenson (National Measurement Institute).![]()
Katharina J. Peters, Lecturer in Biological Sciences, University of Wollongong; Frédérik Saltré, Senior Lecturer in Ecology and Biogeography, University of Technology Sydney; Australian Museum, and Karen Stockin, Professor of Marine Ecology, Te Kunenga ki Pūrehuroa – Massey University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Researchers at the University of Cambridge have developed what they describe as a fundamentally new type of vaccine using artificial intelligence (AI). The vaccine’s key component was designed entirely by AI and has now been tested in people for the first time.
The goal is ambitious: a single vaccine that works not just against all known human coronavirus variants, but against related bat viruses that could jump from animals to humans and cause future pandemics.
Traditional vaccines train our immune system to recognise one specific virus. The problem is that viruses mutate. When they change enough, the vaccine stops working, which is why we need a new flu shot every year and why COVID vaccines have been updated repeatedly since 2021.
AI offers a way around this. By analysing genetic data from thousands of related viruses, it can identify the parts that stay the same across different strains and that are unlikely to change over time. Target those stable features, and you have a vaccine that should work against the whole family, not just the strain you started with.
This is exactly what the Cambridge team did. They used AI to scan viruses from the sarbecovirus family, which includes the viruses that cause both SARS and COVID, as well as a range of animal coronaviruses – looking for shared features that evolution has left largely untouched. Those features became the basis of the vaccine.
While many people are familiar with the mRNA shots used during the pandemic, this new vaccine uses DNA. DNA vaccines are generally more stable than mRNA vaccines, making them easier to store and transport. A significant advantage in lower-income countries where “cold-chain” infrastructure is limited.
They can also be administered without needles. A high-pressure stream of liquid delivers the vaccine through the skin, making administration less painful and easier to scale up during an outbreak.
These practical advantages matter most if the vaccine itself can do something no existing jab can: protect against viruses we haven’t encountered yet.
Broad-spectrum vaccines could change the way the world responds to emerging infectious diseases. By offering much wider protection than traditional vaccines, they could provide rapid immunity against new and emerging viral threats. This would equip public health officials with tools to stop future outbreaks in their tracks before they have a chance to turn into global pandemics.
They could also transform our approach to more familiar diseases. Influenza is a prime target because it exists in many different strains and evolves so rapidly. Scientists have to predict which strains will dominate each flu season, and they guess wrong, vaccine effectiveness can suffer. A universal flu vaccine that targets features shared across multiple strains could eventually end the annual race to keep up with the virus.
And the Ebola virus shows why this matters right now. The recent outbreak in the Democratic Republic of the Congo and Uganda is driven by the Bundibugyo strain, which bypasses existing vaccines. While researchers rush to create a new vaccine specifically for this strain, local communities remain at high risk. A broad-spectrum vaccine designed to cover an entire virus family could transform that picture.
This is the first human trial of an AI-designed vaccine. The results showed that this DNA vaccine was able to stimulate the immune system to produce antibodies that can recognise different types of sarbecoviruses. The technology was found to be safe and well tolerated.
This is an exciting advance because it demonstrates how AI has the potential to design variant-proof vaccines against future pandemic threats. The needle-free delivery system could also make the vaccine easier to administer and distribute worldwide.
However, there is more work to do. Although the results in this study are encouraging, the immune responses following vaccination were modest. It was also uncertain how long the protection lasts and whether further boosters will be required. Larger trials are also needed to determine whether the vaccine can prevent or reduce virus infections in the real world.
A universal vaccine remains a few years away. And any new vaccine must still pass larger trials to prove it is safe, effective and provides lasting protection. But this study shows the goal is getting closer – and AI may help us get there faster.![]()
Neil Mabbott, Personal Chair of Immunopathology, University of Edinburgh
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The United States government’s recent release of hundreds of previously classified Unidentified Anomalous Phenomena (UAPs) cases spanning the 1940s to the present, along with the new Steven Spielberg movie, Disclosure Day, about extraterrestrial life, has fuelled the idea that aliens are visiting Earth.
In fact, polls in Australia, the US and elsewhere indicate around a third of the public believes aliens are here.
However, while what we know about the universe suggests aliens may exist, there are three compelling reasons why they probably aren’t visiting us.
To begin with, space is vast – beyond our imagination.
Proxima Centauri, the nearest star to our Sun, is about 40 trillion kilometres away, 268,000 times farther than the Sun is from Earth. That’s 4.3 light years as astronomers measure it. A light year is the distance light travels in one year at 300,000km per second.
We can only travel across space at a fraction of the speed of light with current technology. Even our fastest spacecraft, the Parker Solar Probe, travels at a top speed of roughly 191 kilometres per second – 0.064% the speed of light.
At that speed, it would take about 6,650 years to reach Proxima Centauri, and that’s just in our local stellar neighbourhood. So interstellar travel within human lifespans would require much higher velocities.
Let’s assume we did have the means to travel close to the speed of light. That introduces the first problem with travelling at that velocity. Albert Einstein demonstrated that time is relative; the rate of time flow is not the same everywhere in the universe. The faster a spaceship travels from Earth, the slower time will pass for its passengers. This is called time dilation.
For example, when NASA astronaut Scott Kelly arrived back on Earth from a year on the International Space Station, he was milliseconds younger than his identical twin because time moves more slowly for objects in motion, and the International Space Station travels at roughly 28,150 kilometres per hour.
This difference was negligible for the Kelly twins. But for any aliens cartwheeling through our skies, it would be significantly more because of the journey to Earth and back from a distant star system at a necessarily higher speed. They would go home to a planet much older than the one they left – perhaps by a century or more. They would be time exiles.
Then there’s the unimaginably high energy requirement for interstellar travel.
The mass of the spaceship increases with velocity, so an increasing amount of energy is required to accelerate it.
At the speed of light, the ship becomes infinitely massive, requiring an infinite amount of energy. This is clearly impossible.
Another significant issue is that space is a vacuum – but not completely. There are just enough particles to worry about. They can potentially cause fatal radiation for passengers and the instruments of a high velocity spacecraft, or destroy it. Sparsely spread hydrogen atoms turn into intense radiation at near light speed, and the heat that is generated would ablate and eventually destroy the hull.
Faster-than-light travel, according to physicist Miguel Alcubierre, is possible, but it comes with its own set of issues and a currently impossible energy requirement.
That raises the question of why spend all this energy to travel to Earth? Anything we have, an advanced civilisation (as they would have to be to get here) would be able to make on their planet.
Yet another issue is our biosphere, unique to Earth as far as scientists know.
Life and the planet co-evolved. Complex life would not exist on Earth if cyanobacteria, a type of single-celled microbe, had not pumped oxygen into our mostly nitrogen atmosphere 2.4 billion years ago.
It’s therefore not toxic for us, but oxygen is reactive and could be highly corrosive for aliens. And while they could wear protective suits like humans do when going to inhospitable environments, reports of visiting aliens do not include any descriptions of spacesuits.
If aliens are not here, are they out there?
It’s an interesting question, scientifically and philosophically. Scientists do not have enough information yet, but they are working on the question.
About 6,200 exoplanets have been found in more than 4,700 solar systems, though none are like Earth or our Solar System.
Most stars could have at least one planet, and there are more than 100 billion stars in our galaxy alone. The number of planets is therefore astronomical, and some may be habitable.
Closer to home, there are worlds with potential for microbial life either past or present – Mars, Europa (a moon of Jupiter), and Enceladus and Titan (moons of Saturn). If we discover life began twice in our Solar System, that will increase the odds of life elsewhere.
Since 1960, we’ve had the capability to look for intelligence elsewhere, piggybacking on normal radio astronomy. The biggest search for alien life projects are carried out by the SETI Institute in California and the Breakthrough Listen project based at Oxford University in the United Kingdom.
Nothing has been found across all the searches made. Finding intelligence in our time frame – about a hundred years – in the 13.8-billion-year history of the universe is challenging.
However, as a 1959 Nature paper noted, while it’s difficult to estimate the chance of success, if we don’t search, the chance drops to zero.![]()
Carol Oliver, Professor in Science Communication and Astrobiology, UNSW Sydney
This article is republished from The Conversation under a Creative Commons license. Read the original article.