Category: English

Source: The Conversation – UK – By Sean Semple, Professor Institute for Social Marketing, University of Stirling

At 6am on a quiet Sunday morning 20 years ago today, Scotland became the first UK nation to ban smoking in enclosed public spaces. It was a landmark moment in public health policy, and new research shows just how much has changed since.

Exposure to secondhand tobacco smoke has fallen by 96% in Scotland since the legislation came into force on March 26 2006. But our new study, published in the journal Tobacco Induced Diseases, reveals that nearly one in four people are still being exposed to tobacco smoke in settings the law does not fully cover. This raises the question of what it will take to finish what the ban started.

The Smoking, Health and Social Care (Scotland) Act 2005 made it illegal to smoke inside bars, restaurants, public transport and almost all workplaces. While there had been much lobbying for exemptions for bars on the basis of size, existing ventilation, or whether or not they also sold food, the law, when it was finally introduced, was comprehensive and simple.

Despite the scale of the change, adoption was rapid and without much dispute. It is now inconceivable that we could ever return to a time when people had to breathe high concentrations of a known carcinogen as they chatted in bars, ate dinner or sat at their workplace desk.

We should take time today to celebrate the impact of the smoking ban. Scotland led the way in the UK and showed it could be done. It also generated extensive evidence through a seven-study evaluation programme that covered everything from hospital admissions for heart attack (reduced by 17% after legislation), to air quality in bars (improved by 86%), to qualitative work examining changes in behaviour, attitudes and social norms.

That detailed and extensive evidence would go on to influence tobacco control policy decisions around the globe for years to come.

Our new analysis examines how Scotland’s exposure to secondhand tobacco smoke has changed in the 20 years since the smoking ban. We used the annual Scottish Health Survey, which gathers data from about 6,000 people across the country, and includes a group of participants who provide a sample of saliva. From this saliva, it is possible to determine the amount of nicotine that someone has inhaled in the past couple of days.

Our analysis shows that adult non-smokers now inhale 96% less nicotine than they did before the ban. Scotland has switched from a nation where seven out of eight non-smokers inhaled other people’s smoke, to a country where three out of four breathe no measurable secondhand tobacco smoke today.

And the progress hasn’t been limited to the settings where the law applies. Our study also provides an analysis of a survey question included since 2012, when people were asked about whether they permit smoking inside their own home. The percentage of homes where smoking is allowed has more than halved in a little over a decade – from 25% to under 10% in 2024.

We’ve made fantastic progress in tackling secondhand smoke exposure in such a short space of time, and it is tempting to see this as a problem solved. But dig deeper and there is a sting in the tail.

The data we present shows that nearly one in four adult non-smokers still breathe secondhand tobacco smoke, and that this figure has been relatively static in the past decade. Workers in many sectors still report they are exposed to other people’s smoke – from those serving in outdoor hospitality settings, to the healthcare workers who provide assistance to people in their own homes.

And as our study reports, we still have about one in ten homes where smoking takes place indoors. While we’ve seen major progress and reductions in that figure, the change also masks a growing inequality. When we look at smoking in the home by deprivation, we see that more than a fifth of households in the most deprived postcodes allow smoking indoors compared with just 2% in the most affluent areas – that inequality gap has doubled since 2012.

Unfinished business

So where next? The tobacco and vapes bill is progressing through the parliament and will provide new powers to extend smoke-free spaces to other settings in the UK.

Consultation on how to use these powers has already started, with options to provide protection in a whole range of outdoor and indoor spaces including playgrounds, at school entrances and in outdoor hospitality settings.

Tackling secondhand smoke in the remaining workplaces and homes where exposure continues to take place is a priority.

As we celebrate 20 years of smoke-free enclosed public spaces in Scotland, it is worth reflecting that the benefits have been extensive. For you it may be that you avoided a hospital admission for a heart attack or stroke, or your child didn’t need that GP appointment for their asthma or glue ear (a common ear infection in children).

Or perhaps it was just the simple joy of not having to wash your hair to get rid of the stink of smoke when you come home from a night out. Whatever your reason, it is little wonder that smoke-free spaces are viewed as one of the most important public health achievements of the first part of the 21st century.

Sean Semple has received research funding from various UK government and EU funding sources (e.g. UKRI, The Chief Scientist Office Scotland, Horizon Europe) and from the Colt Foundation to carry out work on understanding exposure to second-hand smoke. None of this work has been funded by the tobacco industry.

Rachel O’Donnell has received funding from various UK government and EU funding sources (e.g. UKRI, The Chief Scientist Office Scotland) and from Cancer Research UK and the National Institute for Health and Care Research to carry out work on tobacco control and other public health topics. None of this work has been funded by the tobacco industry.

– ref. Scotland’s smoking ban turns 20 – it cut secondhand smoke exposure by 96%, but the job isn’t finished yet – https://theconversation.com/scotlands-smoking-ban-turns-20-it-cut-secondhand-smoke-exposure-by-96-but-the-job-isnt-finished-yet-278939

Source: The Conversation – UK – By Rebecca Dean, Research Fellow, Department of Biology, University of Oxford

When it comes to reproduction, female biology is often described in terms of a ticking clock. Women are born with most of their lifetime supply of eggs, meaning that a woman’s age is usually the same as the age of her eggs. Older women therefore produce older eggs.

But male reproduction works differently. Sperm are produced continuously from puberty onwards and can be stored in the reproductive tract before ejaculation. That means a man’s age is not necessarily the same as the age of his sperm. So what happens to sperm while they wait?

Men trying to conceive are often advised to remain sexually abstinent for several days to allow their sperm count to build up. It is true that abstinence increases sperm count. But the size of the ejaculate is not the only factor that determines fertility. Our new study shows that in men (and other male animals), sperm stored during sexual abstinence actually “ages” and deteriorates in quality.

We already know that male fertility declines with age. What has remained unclear is whether the time sperm spend in storage contributes to this decline.

Answering this question is particularly timely. Sexual activity appears to be declining, especially among young people. Combined with the global trend towards delayed parenthood, this may further exacerbate global fertility declines.

For our investigation, we collected semen data from 115 published studies involving nearly 55,000 men. We found that when men abstained from ejaculation, the health of their sperm dropped significantly. Sperm motility (their ability to swim) and viability decreased – and sperm DNA became more damaged.

We identified two likely causes. The first is oxidative stress – a form of biological “rust” that accumulates in sperm and can physically damage them. The second is energy depletion. Unlike most cells, sperm are highly active and have only a limited capacity to replenish their energy reserves. When stored for extended periods, they simply run out of fuel.

The World Health Organization advises against ejaculating two to seven days before providing a sperm sample for analysis, fertility treatments or procedures such as IVF. However, our findings suggest that even shorter periods may be better if sperm quality in the sample is to be improved.

This supports a recent discovery that ejaculating within 48 hours of providing a sample improves IVF treatment outcomes compared to longer durations of abstinence. It also aligns with a hypothesis in evolutionary biology.

We know that in primates, frequent ejaculation from masturbation improves the quality of ejaculates. Combined with our results, this suggests that male masturbation may have an adaptive benefit: it flushes out damaged, stored sperm.

Sperm does not just deteriorate inside males. It can also deteriorate after mating, when stored inside females. Human sperm only remains alive inside a woman for several days. However, in other animals such as queen ants, bees and female bats, sperm can be stored for several months or even years before eggs are fertilised.

The birds and the bees

To test whether sperm deterioration during storage is a widespread biological pattern, we examined data from 56 studies across 30 different animal species, including birds and bees, reptiles and other mammals. Here too, we found that sperm quality declined during storage.

Fathers who stored sperm before ejaculation, or mothers who stored it before fertilisation, produced embryos with lower chances of survival. We suspect this is not just due to damaged DNA. It may also be that stored sperm have a different gene expression profile – that is, a different pattern of which genes are actively switched on and being used – compared to freshly produced sperm.

Interestingly, sperm deteriorated at a slower rate inside females than inside males. This may be because females in several species have evolved specialised organs that secrete antioxidants, substances that nourish and protect the sperm they are storing, effectively extending their functional lifespan.

Whether in mice or men, sperm, much like eggs, have a “use-by date” after being produced. When sperm are stored for too long before fertilisation, they deteriorate in quality.

Crucially, however, our findings also point to a simple and potentially powerful intervention. Many fertility problems are driven by factors outside our control, such as environmental toxins, stress and genetics. But the duration of sperm storage is something that can be modified. Using freshly ejaculated sperm for fertilisation could therefore provide a meaningful boost to fertility outcomes by improving sperm quality.

Rebecca Dean receives funding from a Daphne Jackson Fellowship funded by NERC.

Irem Sepil receives funding from BBSRC and the Royal Society.

Irem Sepil receives funding from the Royal Society.
Rebecca Dean receives funding from NERC (UKRI).

– ref. Ejaculating more frequently may improve sperm quality – new study – https://theconversation.com/ejaculating-more-frequently-may-improve-sperm-quality-new-study-275373

Source: The Conversation – UK – By Antonios Kelarakis, Reader in Polymers ad Nanomaterials, School of Pharmacy and Biomedical Sciences, University of Lancashire

On November 14 1985, a letter announcing the discovery of a superstable species of carbon appeared in the science journal Nature. Even the letter’s title, C₆₀: Buckminsterfullerene, caused a stir among the journal’s scholarly readers.

Molecules are usually named with sterile precision. This one was named after the American architect and futurist Richard Buckminster Fuller (Bucky to his friends), whose geodesic domes had become icons of modern design in the 1950s and 60s.

Fuller’s spherical domes were designed to be lightweight yet strong, with each triangular element distributing stress evenly across a curved framework. C₆₀ was the atomic analogue of these domes, built not from steel struts but carbon atoms – each joined by strong bonds with three of its neighbours to create a tiny spherical cage.

This new allotrope of carbon was so stable and symmetric that it redrew the map of molecular architecture. It kicked off a scientific sprint that led, barely a decade later, to the 1996 Nobel prize in chemistry for English scientist Harold Kroto and his American colleagues Robert Curl and Richard Smalley for their discovery.

Fullerenes (now nicknamed Buckyballs) had always existed on Earth – in candle soot, volcanic emissions and ancient minerals. But their scientific discovery emerged from an attempt to simulate the chemistry of carbon-rich red giant stars.

The discovery opened the era of nanotechnology – the manufacture and manipulation of materials at previously impossibly small scales. But this is not the only way Fuller’s name is remembered in science.

Who was Buckminster Fuller?

Few 20th-century figures are as hard to classify as Fuller. He was, at the least, an inventor, designer, engineer, writer, philosopher and futurist. Born in Massachusetts in 1895, his formal education was brief and rather turbulent – he was expelled twice from Harvard University. Yet this did not lessen his ambition to redesign the world.

Fuller could be eccentric and sometimes controversial. His early enterprises frequently failed, yet his charisma and boundless optimism made him a compelling public figure. The result was a remarkable portfolio of inventions and concepts, showcasing bold prototypes and radical ideas.

His earliest geodesic domes were built from lightweight materials, typically steel tubular struts connected in a triangular lattice and clad with acrylic panels. They capitalised on the structural advantage of symmetry: enclosing a vast space with relatively little material and remaining exceptionally strong.

Fuller patented the design in 1951. Despite initial scepticism from some in the architectural establishment, geodesic domes soon found practical applications. The US Marine Corps used them for rapidly deployable radar stations in Arctic conditions.

One of the most famous examples is the giant dome built for the Expo 67 international exposition in the Canadian city of Montreal. Known today as the Montreal Biosphere, the structure became one of the most recognisable symbols of futuristic architecture in the 1960s.

Alongside his designs, Fuller spent much of his life developing Synergetics, a philosophical-geometric framework exploring how structures and energies interact in nature. At the heart of this work was “ephemeralisation” — a term Fuller coined to describe the process of achieving ever greater results with fewer materials and less energy.

In later life, he became a global intellectual celebrity, delivering thousands of lectures around the world. Fuller captivated audiences with a unique vision of design, technology and planetary stewardship — once delivering a marathon series of lectures entitled “Everything I know”. It ran for 42 hours.

The power of symmetry

Symmetry is among science’s most powerful unifying codes and one of its most versatile interpretive tools. It reveals surprising equivalences between forms that differ in size but not in structure.

In the 1960s, footballs adopted a similar geometry to Fuller’s geodesic dome: a combination of 12 pentagons and 20 hexagons stitched into a resilient mesh to absorb force and rolls with minimal deformation. Indeed, a diagram of a football was used to illustrate the announcement of C₆₀: Buckminsterfullerene.

This series is dedicated to lesser-known, highly influential scientists who have had a powerful influence on the careers and research paths of many others, including the authors of these articles.

A growing family of atom-thin, superstrong materials has emerged since that 1985 Nature letter. These include the tiny-in-diameter but much longer carbon nanotubes in 1991, and the one-atom thick graphene in 2004 – both of which are now widely used in electronics, sensors, composites and energy devices.

When added to polymer composites or metal alloys, these tiny carbon cages strengthen and lighten materials, enhancing performance in everything from aircraft components and solar panels to medical tools including MRI scanners.

Doing more with less

The structure of fullerenes naturally realises Fuller’s principle of ephemeralisation – the ability to do more and more with less and less.

Fuller imagined technological progress as a path toward efficiency, elegance, sustainability and abundance. He applied ephemeralisation across his designs, harnessing science and geometry to achieve maximum performance with minimal resources.

Beyond geodesic domes, his innovations included the Dymaxion House – a prefabricated, environmentally efficient home designed for easy mass production and transport – and the Dymaxion Car. Patented in 1933, its streamlined aerodynamic bodywork was designed to carry more passengers while improving both fuel efficiency and top speed.

Fuller also imagined radical solutions for extreme environments. These included the Undersea Island – a submerged base anchored by crisscrossing cables to stay rock steady in storms – and the suspension building system, which inverted the idea of a suspension bridge into an arched dome that created vast interior space with minimal material.

Fuller died in 1983 after a lifetime spent redesigning the world – and reimagining how humanity might live. Two years later, chemistry paid him an unexpected tribute: a perfectly symmetrical carbon molecule was named after him, recognising his lifelong dedication to geometrical efficiency.

In the nanosized Buckyball, Fuller’s aspirational social ideas are encapsulated in a molecule that embodies minimalism, efficiency and intelligent design.

Antonios Kelarakis 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. My unsung hero of science: Buckminster Fuller, the architect who wanted to redesign the world (and inspired a nanosized one) – https://theconversation.com/my-unsung-hero-of-science-buckminster-fuller-the-architect-who-wanted-to-redesign-the-world-and-inspired-a-nanosized-one-278272

Source: The Conversation – UK – By Costas Velis, Lecturer in Resource Efficiency Systems, School of Civil Engineering, University of Leeds; Imperial College London

The world is struggling to deal with ever-growing quantities of waste.

A new World Bank Group report, What a Waste 3.0, shows that more than 2.6 billion tonnes of municipal solid waste (which includes rubbish from households, businesses and street cleaning) were generated in 2022. That figure is projected to rise to 3.9 billion tonnes by 2050. The good news is that the share of waste that is mismanaged is expected to fall over that period, from around 30% to around 20%.

That sounds like progress. But percentages can be misleading. The quantity of mismanaged waste, including plastics, is projected to remain almost unchanged, at around 760 million tonnes. This means that by 2050, enormous quantities of waste will still be openly dumped, burned or otherwise unmanaged, with many households and communities left to deal with it themselves.

This new report, which we contributed to, brings together the most recent publicly accessible municipal waste data from 217 countries and economies (such as the Channel Islands) and 262 cities. It highlights that although waste systems are improving in many places, those gains are being undermined by the growth in the amount of waste generated.

This matters because when waste is not managed properly, the consequences affect human health, the environment and the economy. Poor waste management contributes to air and water pollution, damages ecosystems, increases greenhouse gas emissions and makes cities harder and less pleasant to live in.

One of the clearest examples is open burning. In many developing countries, where formal waste collection remains incomplete or absent, open burning is one of the main ways households and communities “self-manage” their waste. These fires burn at low and uneven temperatures. Combined with a mixed waste stream that can include plastics, organics and other materials, they release a complex cocktail of pollutants that can threaten the health of people living and working nearby.

With new data on self-management, this report shows how waste is actually managed across large parts of the world, especially where formal systems remain weak. Forms of self-management of waste include open dumping, open burning, burying waste in informal pits, dumping into waterways and coastal waters, and some forms of informal recovery such as recycling or composting.

Read more:
Health crisis: up to a billion tonnes of waste potentially burned in the open every year

So if the harms of poor waste management are well known, why does the problem persist?

One reason is cost. Municipal waste management is resource intensive. Many countries are still spending far less than is needed to provide universal and reliable services. Our analysis suggests that even basic systems involving collection, transport and disposal tend to cost at least US$40 (£30) to US$45 per tonne in low-income countries. In middle-income countries, basic systems cost roughly US$70 to US$80 per tonne, while in high-income countries costs can exceed US$200 per tonne.

At those cost levels, low-income countries would have needed around 0.78% of their combined GDP in 2022 to achieve universal waste management coverage. Middle-income countries would have needed roughly 0.31% to 0.46% of GDP. Yet reported public spending on solid waste management is less than 0.15% of GDP in about three-quarters of low- and middle-income countries and 0.31% in high income countries.

That financing gap helps explain why waste collection is not comprehensively provided, why open dumping is still common and why so many people are left to manage waste themselves.

The total financial costs are also rising fast. Globally, municipal waste management cost more than US$250 billion in 2022. Under a business-as-usual scenario, that annual cost is projected to reach US$426 billion by 2050.

Shifting the costs

The cost of inaction is higher than these service costs alone suggest. Poor waste management brings wider economic losses, for example through ill health, reduced land values, damaged ecosystems, lost materials and harm to sectors such as tourism, agriculture and fisheries.

The world may not be saving money by underinvesting in waste management. It is shifting the costs elsewhere – onto public health, the environment and future generations.

Read more:
Plastic pollution hotspots pinpointed in new research – India ranks top due to high levels of uncollected waste

This is especially important in low- and lower-middle-income countries, where waste generation is rising rapidly, but service coverage and infrastructure are often far below sufficient levels. This report estimates that these countries will require hundreds of billions of dollars in investment over the next 25 years just to expand and improve municipal waste systems. Without faster investment, existing service gaps will widen and the costs of inaction will grow.

The world’s waste crisis cannot be understood only as an environmental problem. It is also a financing, public health, governance and development problem. Better data helps us see that more clearly.

Waste management is improving, but not fast enough. Unless investment and performance accelerate, the amount of mismanaged waste worldwide is unlikely to change, causing harm to public health.

Costas Velis has consulted for UNEP – International Environmental Technology Centre, the Organisation for Economic Co-operation and Development (OECD), EMG, the Resources and Waste Advisory Group (with funds from GIZ), the ICF (with funds from The Pew Charitable Trusts), and MARS Inc. via Imperial Consultants). He receives funding from UK Research Innovation and Global Challenges Research Fund, Grid-Arendal, The World Bank Group via UN Operations and the International Union for Conservation of Nature, and the EU via UK Research Innovation grant agreement. He serves on the steering committee for project STOP by SYSTEMIQ Indonesia; was Chair of the International Solid Waste Association Marine Litter Task Force; is on the policy and innovation forum for the Chartered Institution of Wastes Management; He is member of and served at Steering Committee of the Scientist’s Coalition for an Effective Plastics Treaty, and is the owner and Director of Fuelogy, a small research consultancy registered in the UK that offers scientifically impartial services in solid waste management, resource recovery and the circular economy to sustainability-focused consultancies, non-governmental organisations, and international organisations.

Ed Cook has consulted for: Women in Informal Employment, Globalizing and Organizing (WIEGO), World Bank Group, Julie’s Bicycle, Vision 2025, ICF (funded by Pew Charitable Trust), OHE, WasteAware (funded by GIZ), IUCN (funded by World Bank via UNOPs). He has worked on research projects funded by: Grid Arendal (funded by NORAD), Mars, Eunomia Research and Consulting (funded by The World Bank Group), and ICF (funded by the Pew Charitable Trust). He is a Chartered Waste Manager with the Chartered Institute of Wastes Management in the UK, a member of The Scientists’ Coalition for an Effective Plastics Treaty, and a member of the International Solid Waste Association.

– ref. The world’s waste mountain is rising at an alarming rate – https://theconversation.com/the-worlds-waste-mountain-is-rising-at-an-alarming-rate-278627