̽��ֱ�� of Cambridge - ̽��ֱ�� of Leeds

Scientists develop new method to assess ozone layer recovery

sc604 — Wed, 24 Aug 2022 14:58:39 +0000

Published in the journal Nature, their method - the Integrated Ozone Depletion (IOD) metric - provides a useful tool for policymakers and scientists.

̽��ֱ��IOD has been designed to provide a straightforward way to measure the effects of unregulated emissions of substances that deplete the ozone layer, and evaluate how effective ozone layer protection measures are.

̽��ֱ��ozone layer is found in a region of the earth’s atmosphere known as the stratosphere, and acts as an important protection barrier against most of the sun’s harmful ultraviolet rays.

Ozone-depleting gases such as chlorofluorocarbons, better known as CFCs, have been phased out under the Montreal Protocol - an international treaty agreed to protect the ozone layer.

̽��ֱ��Montreal Protocol has been largely successful, but illegal breaches are jeopardising its efficacy.

̽��ֱ��IOD indicates the impact of any new emissions on the ozone layer by considering three things: the strength of the emission, how long it will remain in the atmosphere, and how much ozone is chemically destroyed by it.

For environmental protection and human health policies, the IOD represents a simple means of calculating the impact of any given emission scenario on ozone recovery.

This new metric has been developed by researchers at the National Centre for Atmospheric Science at the ̽��ֱ�� of Cambridge and the National Centre for Earth Observation at the ̽��ֱ�� of Leeds.

Professor John Pyle, from the National Centre for Atmospheric Science and the ̽��ֱ�� of Cambridge, has dedicated his career to studying the depletion of ozone in the stratosphere and helping develop the Montreal Protocol. He is the lead author of the current Nature paper.

“Following the Montreal Protocol, we are now in a new phase - assessing the recovery of the ozone layer,” said Pyle, from Cambridge’s Yusuf Hamied Department of Chemistry. “This new phase calls for new metrics, like the Integrated Ozone Depletion - which we refer to as the IOD. Our new metric can measure the impact of emissions - regardless of their size. Using an atmospheric chemistry computer model, we have been able to demonstrate a simple linear relationship between the IOD, the size of the emissions and the chemical lifetimes. So, with knowledge of the lifetimes, it is a simple matter to calculate the IOD, making this an excellent metric both for science and policy.”

“ ̽��ֱ��Montreal Protocol is successfully protecting the ozone layer, but there is increasing evidence to suggest the ozone hole is recovering slower than expected. ̽��ֱ��IOD will be very useful for monitoring ozone recovery, and especially relevant to regulators who need to phase out substances with the potential to chemically destroy ozone.”

̽��ֱ��IOD metric has been created using a computer model of the atmosphere, called the UK Chemistry and Aerosols model (UKCA). ̽��ֱ��National Centre for Atmospheric Science and the Met Office developed the UKCA model to calculate future projections of important chemicals, such as ozone in the stratosphere.

“We have used the UKCA model to develop the IOD metric, which will enable us to estimate the effect of any new illegal or unregulated emissions on the ozone layer. In the UKCA model we can perform experiments with different types and concentrations of CFCs, and other ozone-depleting substances,” said co-author Dr Luke Abraham, also from the ̽��ֱ�� of Cambridge. “We can estimate how chemicals in the atmosphere will change in the future, and assess their impact on the ozone layer over the coming century.”

̽��ֱ��research was supported in part by the Natural Environment Research Council (NERC), part of UK Research and Innovation (UKRI).

Reference:
John A Pyle et al. ‘Integrated ozone depletion as a metric for ozone recovery.’ Nature (2022). DOI: 10.1038/s41586-022-04968-8

Adapted from a press release by the National Centre for Atmospheric Science.

Researchers have developed a new method for assessing the impacts of ozone-destroying substances that threaten the recovery of the ozone layer.

̽��ֱ��Montreal Protocol is successfully protecting the ozone layer, but there is increasing evidence to suggest the ozone hole is recovering slower than expected

John Pyle

Grant Faint via Getty Images

View of Earth from 40,000 feet

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Scientists develop model to assess COVID-19 infection risk in offices and schools

sc604 — Wed, 06 Oct 2021 10:56:27 +0000

̽��ֱ��model – developed by researchers at the ̽��ֱ�� of Cambridge, Imperial College London and the ̽��ֱ�� of Leeds – uses monitored CO2 and occupancy data to predict how many workers are likely to be infected by an asymptomatic but infectious colleague.

Applications of the infection model have demonstrated that most workers in well-ventilated, quiet offices are unlikely to infect each other via airborne particles, but the risk becomes greater if the space is poorly ventilated or if the workers are involved in activities that require more speaking. For instance, the model predicts each infected person could infect two to four others in an adequately ventilated but noisy call centre. Risks are also likely to increase if the infected individual is a ‘super spreader’.

̽��ֱ��model also suggests that halving the occupancy of an office could reduce the risk of airborne transmission four-fold. ̽��ֱ��results are reported in the journal Indoor and Built Environment.

In areas with lower ventilation rates and high occupancy, CO2 levels are higher, so monitoring them can provide a warning to building managers to identify areas where the risk of airborne transmission of COVID-19 are higher. Achievable interventions can then be made, for instance, to improve ventilation or change worker attendance patterns to reduce occupancy.

In shared spaces such as offices and classrooms, exposure to infectious airborne matter builds up, and room occupancy may vary. By using carbon dioxide levels as a proxy for exhaled breath, the model can assess the variable exposure risk as people come and go.

“Ventilation is complicated and airflow is invisible, so it’s hard for people to appreciate the effects in the home or workplace,” said co-author Professor Paul Linden from Cambridge’s Department of Applied Mathematics and Theoretical Physics. “Commercially available CO2 monitors are being installed in schools and I would recommend their installation in the workplace.”

“Our work emphasises the importance of good ventilation in workplaces and in schools,” said lead author Dr Henry Burridge, from Imperial College London. “ ̽��ֱ��model demonstrates that by managing the ventilation and occupancy levels of shared spaces we can manage the risk of airborne infection by a virus such as that which causes COVID-19.”

“ ̽��ֱ��appropriate use of tools such as CO2 monitoring can give building managers a much better understanding of their own ventilation systems and how they are performing for each activity undertaken in the space,” said Professor Andrew Curran, Chief Scientific Adviser at the Health and Safety Executive and lead for the PROTECT study. “For most businesses, a COVID-19 control strategy will involve a blended combination of measures identified through a risk assessment – there is no silver bullet.”

̽��ֱ��research was funded by the PROTECT COVID-19 National Core Study and the Engineering and Physical Sciences Research Council (EPSRC, part of UK Research and Innovation).

Reference:
Henry C Burridge et al. ‘Predictive and retrospective modelling of airborne infection risk using monitored carbon dioxide.’ Indoor and Built Environment (2021). DOI: 10.1177/1420326X211043564

Adapted from an HSE press release.

As more UK workers and students return to offices and schools, a new model has been developed to predict the risk of airborne COVID-19 infection in such environments.

Ventilation is complicated and air flow is invisible, so it’s hard for people to appreciate the effects in the home or workplace

Paul Linden

Israel Amdrade via Unsplash

People in office sitting in front of computers

Yes

Scientists reverse age-related memory loss in mice

sc604 — Thu, 22 Jul 2021 14:18:03 +0000

In a study published in Molecular Psychiatry, the team show that changes in the extracellular matrix of the brain – ‘scaffolding’ around nerve cells – lead to loss of memory with ageing, but that it is possible to reverse these using genetic treatments.

Recent evidence has emerged of the role of perineuronal nets (PNNs) in neuroplasticity – the ability of the brain to learn and adapt – and to make memories. PNNs are cartilage-like structures that mostly surround inhibitory neurons in the brain. Their main function is to control the level of plasticity in the brain. They appear at around five years old in humans, and turn off the period of enhanced plasticity during which the connections in the brain are optimised. Then, plasticity is partially turned off, making the brain more efficient but less plastic.

PNNs contain compounds known as chondroitin sulphates. Some of these, such as chondroitin 4-sulphate, inhibit the action of the networks, inhibiting neuroplasticity; others, such as chondroitin 6-sulphate, promote neuroplasticity. As we age, the balance of these compounds changes, and as levels of chondroitin 6-sulphate decrease, so our ability to learn and form new memories changes, leading to age-related memory decline.

Researchers at the ̽��ֱ�� of Cambridge and ̽��ֱ�� of Leeds investigated whether manipulating the chondroitin sulphate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.

To do this, the team looked at 20-month old mice – considered very old – and using a suite of tests showed that the mice exhibited deficits in their memory compared to six-month old mice.

For example, one test involved seeing whether mice recognised an object. ̽��ֱ��mouse was placed at the start of a Y-shaped maze and left to explore two identical objects at the end of the two arms. After a short while, the mouse was once again placed in the maze, but this time one arm contained a new object, while the other contained a copy of the repeated object. ̽��ֱ��researchers measured the amount of time the mouse spent exploring each object to see whether it had remembered the object from the previous task. ̽��ֱ��older mice were much less likely to remember the object.

̽��ֱ��team treated the ageing mice using a ‘viral vector’, a virus capable of reconstituting the amount of 6-sulphate chondroitin sulphates to the PNNs and found that this completely restored memory in the older mice, to a level similar to that seen in the younger mice.

Dr Jessica Kwok from the School of Biomedical Sciences at the ̽��ֱ�� of Leeds said: “We saw remarkable results when we treated the ageing mice with this treatment. ̽��ֱ��memory and ability to learn were restored to levels they would not have seen since they were much younger.”

To explore the role of chondroitin 6-sulphate in memory loss, the researchers bred mice that had been genetically-manipulated such that they were only able to produce low levels of the compound to mimic the changes of ageing. Even at 11 weeks, these mice showed signs of premature memory loss. However, increasing levels of chondroitin 6-sulphate using the viral vector restored their memory and plasticity to levels similar to healthy mice.

Professor James Fawcett from the John van Geest Centre for Brain Repair at the ̽��ֱ�� of Cambridge said: “What is exciting about this is that although our study was only in mice, the same mechanism should operate in humans – the molecules and structures in the human brain are the same as those in rodents. This suggests that it may be possible to prevent humans from developing memory loss in old age.”

̽��ֱ��team have already identified a potential drug, licensed for human use, that can be taken by mouth and inhibits the formation of PNNs. When this compound is given to mice and rats it can restore memory in ageing and also improves recovery in spinal cord injury. ̽��ֱ��researchers are investigating whether it might help alleviate memory loss in animal models of Alzheimer's disease.

̽��ֱ��approach taken by Professor Fawcett’s team – using viral vectors to deliver the treatment – is increasingly being used to treat human neurological conditions. A second team at the Centre recently published research showing their use for repairing damage caused by glaucoma and dementia.

̽��ֱ��study was funded by Alzheimer’s Research UK, the Medical Research Council, European Research Council and the Czech Science Foundation.

Reference
Yang, S et al. Chondroitin 6-sulphate is required for neuroplasticity and memory in ageing. Molecular Psychiatry; 16 July 2021; DOI: doi.org/10.1038/s41380-021-01208-9

Scientists at Cambridge and Leeds have successfully reversed age-related memory loss in mice and say their discovery could lead to the development of treatments to prevent memory loss in people as they age.

Although our study was only in mice, the same mechanism should operate in humans – the molecules and structures in the human brain are the same as those in rodents. This suggests that it may be possible to prevent humans from developing memory loss in old age

James Fawcett

Michael Shribak, Marine Biological Laboratory, Woods Hole, MA

Spatially oriented neurons (mouse brain)

Yes

Licence type:

Attribution-Noncommerical

Scientists track veil of toxic metals carried in Kīlauea’s gas plumes, revealing hidden dangers of volcanic pollution

cmm201 — Tue, 25 May 2021 16:53:48 +0000

̽��ֱ��research, published in two companion papers in Nature Communications Earth and Environment, is the most extensive survey of metal release from any volcano to date – helping scientists understand the spread of metal-rich volcanic fumes and the exposure of communities to volcanic air pollution around Hawai’i.

̽��ֱ��2018 eruption of Kīlauea was the largest in centuries, flooding the eastern edge of the island with roughly a cubic kilometres of lava. Over a thousand people lost their homes and many more suffered from noxious volcanic gases.

Understanding how volcanic metals are released to the environment is critical from a public health perspective, “We don’t know much about these metal emissions at all, so this work is a key step to understanding the significant, yet underestimated, chemical risks of volcanoes,” said Emily Mason, PhD student at Cambridge Earth Sciences and lead author of one of the papers.

When volcanoes erupt they exhale a cocktail of gases – mostly steam, carbon dioxide and sulphur dioxide – laced with evaporated heavy metals, including lead and arsenic. To the communities living alongside volcanoes, these gases are often a considerable source of air pollution and the volatile metals they carry may have long-lasting impacts on both health and environment.

Volcanologists have been measuring volatile metal emissions from volcanoes for decades, but how these elements are dispersed in the atmosphere following an eruption, to later rain down on the landscape and be taken up in the environment through soils and water bodies, has remained poorly understood.

̽��ֱ��team, including researchers from the ̽��ֱ�� of Cambridge, report higher concentrations of airborne heavy metals within a 40 km radius of Kīlauea, meaning that communities living closer to the volcano were disproportionally exposed to metal pollution during the 2018 eruption.

They believe that the strong trade winds at the time of the eruption, combined with the topography of the local area, caused higher rainfall and, therefore metal deposition, closer to the vent. This could mean that an eruption in winter, when wind patterns are reversed, might result in a different distribution of metal deposition.

Their results could help delineate environmental monitoring strategies during and following eruptions – including the targeted testing of community water supplies in at-risk areas – as well as helping planners decide where to build safely around volcanoes.

Emily Mason was one of an all-female team of scientists from the Universities of Cambridge and Leeds that headed out to take gas measurements when Kīlauea erupted. Mason, together with then first-year PhD students Penny Wieser and Rachel Whitty, and early career scientists Evgenia Ilyinskaya and Emma Liu, arrived when the eruption was in full flow and some of their study area was already cut off by lava, “We had to fly in to one location via helicopter. I remember descending through a dense haze of volcanic gas…the acidic air actually stung our skin.” said Mason.

“We tend to think of the more immediate volcanic hazards like ash fall, pyroclastic flows, lava,” said Dr Evgenia Ilyinskaya, from the ̽��ֱ�� of Leeds, who led the research on downwind metal dispersal, “But metal emissions, just like air pollution, are an insidious and often underestimated volcanic hazard – potentially impacting health over long periods.”

During the first few weeks of the eruption, the main air quality concern was volcanic smog, or ‘vog’, which contains mostly sulfur dioxide with traces of heavy metals and volcanic ash. But when molten lava reached the ocean and reacted with seawater it triggered new health warnings, as billowing white clouds of lava haze or ‘laze’ were released; carrying hydrochloric acid and toxic metals.

Working with collaborators from the USGS, the team took measurements of gases inside the laze and dry vog plumes from both the ground and the air, using specially-fitted drones. They even developed a back frame for their air filters, so they could move equipment quickly through areas where the air was thick with sulphur dioxide.

Mason and co-authors discovered that the two types of gas plume had a very different chemistry, “What really surprised us was the large amounts of copper in the laze plume…the impact of lava-seawater interactions on the biosphere may be significantly underestimated. It’s interesting to note that this type of plume was probably a common feature of the massive outpourings of lava throughout geological history – some of which have been linked to mass extinctions.”

Their long-term goal is to produce pollution hazard maps for volcanoes, showing at-risk areas for metal pollution, a method already used to communicate areas that might be at risk of other volcanic hazards, like lava flows, “Our research is just one part of the puzzle – the idea would be to understand all of these hazards in tandem”.

They aim to apply this method worldwide, but Mason cautions that local atmospheric conditions significantly influence metal dispersal and deposition. Now they want to know how the transport of volcanic metals might differ in cooler, drier environments like the Antarctic – or even in different areas of Hawai’i where rainfall is lower.

Ilyinskaya, Evgenia, et al. "Rapid metal pollutant deposition from the volcanic plume of Kīlauea, Hawai’i." Communications Earth & Environment 2.1 (2021): 1-15.

Mason, Emily, et al. "Volatile metal emissions from volcanic degassing and lava–seawater interactions at Kīlauea Volcano, Hawai’i." Communications Earth & Environment 2.1 (2021): 1-16.

A team of volcanologists who observed the colossal 2018 eruption of Kīlauea, Hawai’i, have tracked how potentially toxic metals carried in its gas plumes were transported away from the volcano to be deposited on the landscape.

This work is a key step to understanding the significant, yet underestimated, chemical risks of volcanoes

Emily Mason

Emily Mason/USGS

Golden Hour at Kīlauea

Yes

Fibre-optics used to take the temperature of Greenland Ice Sheet

sc604 — Fri, 14 May 2021 17:09:27 +0000

Scientists have used fibre-optic sensing to obtain the most detailed measurements of ice properties ever taken on the Greenland Ice Sheet. Their findings will be used to make more accurate models of the future movement of the world’s second-largest ice sheet, as the effects of climate change continue to accelerate.