Cookware handles, electrical plugs, brake pads. Unlike other plastics, these ‘thermosets’ cannot simply be melted down and reshaped, making them difficult to recycle. Chemist Roxanne Kieltyka and her team are now exploring a way to make these materials recyclable, potentially transforming the way we…

On paper it is recycled, but in reality enormous quantities of plastic waste from the Netherlands end up in Asian seas. Researchers from the Leiden Institute of Environmental Sciences charted the fate of plastic food packaging waste from the Netherlands. They published their results on July 8 in the…

Leiden PhD candidate Jo-Anne Verschoor discovered that nearly twenty percent of the bacterial strains she studied could degrade plastic, though they needed some encouragement to do so. ‘Bacteria are just like people,’ says Verschoor. Her research was published in the journal Communications Biology,…

A group of biology students are working on a solution to the world’s plastics problem by getting bacteria to make biodegradable plastic.

We all know smoking is bad for our health. But we might not have known that the cigarette filters that litter our streets also impact the environment. Esther Kentin is a lecturer at Leiden Law School. She is raising awareness of the University’s cigarette butt problem.

What motivates citizens to participate in a citizen science project on plastic pollution? And does that motivation change over time? Liselotte Rambonnet tried to answer these and other questions with her research on the Clean Rivers (‘Schone Rivieren’) project. Rambonnet is a PhD student at the Institute…

Whales in the vicinity of the city of Auckland, New Zealand consume large amounts of microplastics every day. A team of international researchers reached this conclusion after carefully examining whale poop. The team included Thijs Bosker, Associate Professor in Environmental Sciences at Leiden University…

Micro- and nanoplastics cause stress to crops such as lettuce and carrots, PhD candidate Laura Julia Zantis found. This can lead to reduced growth and a lower nutritional value. Biodegradable plastics have this effect too, likely because of chemicals they release during degradation.

Leiden researchers have discovered an enzyme that helps bacteria feed on everyday plastics. This common enzyme could play a crucial role in future research and eventually in addressing the global plastic crisis. The study was published in Nature Communications.

Countries that import plastic waste recycle an average of at least 63 percent of it. This is surprising, as we previously believed that the vast majority was incinerated or ended up as litter. This was discovered by PhD candidate Kai Li and his colleagues from the Institute of Environmental Sciences in…

Nano-plastics cause malformations. Meiru Wang, researcher at the Institute of Biology Leiden, looked at the extreme effects polystyrene nano-particles could have, using chicken embryos as a model. Her results were quite alarming. Especially as nano-particles are everywhere. In the air, floating through…

In the Port of Rotterdam, tiny industrial pellets leak into the environment, causing a form of pollution that’s hard to trace but highly persistent. Three students of the LDE Sustainability Honours Programme took on the challenge to identify sources of this pollution.

What looked like an ordinary coot’s nest turned out to be a five-star location with a remarkable backstory. Beneath a jetty on the Rokin in Amsterdam, biologist Auke-Florian Hiemstra discovered a true time capsule — complete with face masks from the COVID era and a Mars wrapper dating back to the 1994…

The university is launching a campaign to focus extra attention on our smoke-free university locations. The University is using aptly named cigarette barrels to try to show clearly just how many cigarette filters are being saved from the environment. How harmful are these cigarette filters to the e…

Nanoplastics can accumulate in developing hearts, according to a study by biologist Meiru Wang from Leiden University. Her research on chicken embryos sheds new light on how these tiny plastic particles pose a threat to our health.

In recent months, the university has been running the 'Smoke-free university' campaign because of the large number of cigarette waste on and around the faculties. As part of this campaign, gatherings were held in June, September and October to draw extra attention to this waste problem.

Canal Watch (De Grachtwacht), which has been cleaning canals since 2018, has received the Dutch Research Council (NWO) Communication Initiative Award.

Defending your PhD research in front of nearly 300 elementary school students: that was the challenge faced by PhD candidates Jo-Anne Verschoor and Marinka de Willigen during the VUURVLIEGEN competition organised by the Centrum JongerenCommunicatie Chemie (C3). After an exciting competition, the children…

The construction of 285 student studios on land owned by Leiden University is a step closer. On Thursday, student housing organisation DUWO and the Real Estate department of the University signed the leasehold agreement for the parcel of land in the Oegstgeest part of the Leiden Bio Science Park.

Prof. dr. Pancras Hogendoorn is stepping down as dean of the Faculty of Medicine and vice-chair of the Executive Board of Leiden University Medical Centre (LUMC). He is also resigning from all associated secondary posts. Hogendoorn has taken his decision in anticipation of the findings of an inquiry…

After nearly five years as President of the Executive Board, Annetje Ottow will be stepping down from the role as of 1 September. During her time as President, she helped shape the university’s strategic direction, strengthening its regional, European and international profile. Sustainability, and dignity…

Arts and leisure, Arts and leisure

A patent for what may be a potent, new antibiotic. And: a clear overview of promising approaches to overcome a crucial resistance tactic employed by bacteria. In the span of one week, two researchers from Leiden are receiving their PhDs, each of them on an important step in the battle against bacteria…

How do atoms and molecules end up forming planets? That's what astrochemist Julia Santos studied during her PhD. She discovered the dominant process behind the formation of methanol in space – a finding that surprised the entire field.

‘We’re going to see each other again on campus. We’re so pleased, but we do have to say safe.’ Rector Magnificus Hester Bijl is looking ahead to the new academic year, which begins on 6 September. No more 1.5m distancing, but we do have to take responsibility for other people’s safety.

The experiential expertise of people with a disability needs to be integrated in diversity & inclusion policy. This message was the common thread at the annual Diversity & Inclusion symposium. Students and staff members engaged in conversation about how the university can become more accessible.

Koen Keijzer combined three mathematical models into one unified system capable of making meaningful predictions about how cells form blood vessels. This helps biologists studying the chaotic, leaky blood vessels found in and around tumours.

Gilles van Wezel will step down as Scientific Director (SD) of the Institute of Biology Leiden (IBL) as of June 17th. He has held this position since September 2018. Van Wezel will be temporarily succeeded by Hubertus Irth, the current SD of the Leiden Academic Centre for Drug Research (LACDR). Irth…

Having served on the Executive Board for over nine years, the last five of which as Rector Magnificus, Hester Bijl will leave Leiden University at the start of next year. In a new step in her career, she will become Rector Magnificus on the Executive Board of Delft University of Technology (TU Delft)…

Herman Spaink knows of many substances that may help combat tuberculosis. Lab space to study them safely is very limited in Leiden. A brand-new lab at Universitas Gadjah Mada in Indonesia will soon provide a solution. About time, says Spaink, ‘The disease is on the rise and is becoming less sensitive…

Gain the knowledge and skills you need to make an impact on sustainability issues.

Henk Hoekstra and Alessandra Silvestri work on the astronomy and theoretical physics in the Euclid mission. These Dutch researchers are part of the mission.

Some thirty Leiden students balanced on SUP boards for the Supping for Sustainability Lustrum activity. Together with alumnus Merijn Tinga, better known as the Plastic Soup Surfer, they paddled their boards through the Leiden canals and waterways, fishing plastic waste out of the water.

Ammonia has been feeding the world for decades as a fertiliser and is now rapidly emerging as a carbon free fuel for shipping and industry. But if we focus only on CO₂ emissions, we risk creating new nitrogen problems, warns nitrogen expert Jan Willem Erisman in the journal One Earth.

Leiden's iGEM team has won high honours at the Grand Jamboree in Paris. The biology students came second in the Overgraduate category with their project PHAse Out. They also took home awards for Best Biomanufacturing Project, Best Wiki and Best Entrepreneurship as well as a Gold Medal. To top it all…

Life returned to something resembling normal after Covid but other crises soon took its place. These great challenges are also being felt at the University and our researchers are working on solutions. The nitrogen crisis, problems with young people’s services and an increasingly urgent climate crisis:…

Student wellbeing

Cryogenic memories, antibiotic treatment for urinary tract infections and recycling plastic sustainably. These are the subjects of the three NWO-XS grants awarded to Leiden Science researchers.

Professor of Fungal Genetics and Biotechnology Arthur Ram explains how fungi can help us be more sustainable.

Career and apply for jobs, Study support