Wednesday, May 04, 2022

New portal improves forecasts of devastating storms in West Africa

Online tool will enable forecasters to provide communities with more reliable warnings

Business Announcement

UK CENTRE FOR ECOLOGY & HYDROLOGY

Nowcasting portal 

IMAGE: THIS IMAGE FROM THE PORTAL SHOWS STORMS (IN RED) ACROSS WEST AFRICA ON THE EVENING OF 27 APRIL 2022. view more 

CREDIT: © MAPBOX © OPENSTREETMAP © 2022 EUMETSAT

An online portal developed by the UK Centre for Ecology & Hydrology (UKCEH) will enable forecasters in West Africa to provide communities with earlier and more reliable warnings about large storms.

Storms in the Sahel region, which can reach over 100km in size, have become more extreme since the 1980s due to global warming, with more intense rainfall.* Severe flooding during the monsoon from June to September causes human and livestock deaths, plus damages property and infrastructure, leaving thousands of people without homes and livelihoods.

State-of-the-art weather forecast models struggle to predict where new storms will hit and how strong they will be, which makes it difficult to provide warnings to people in affected areas so they can protect their property and livestock or get out of harm’s way.

National forecasting agencies in Africa can already make predictions of how storms will behave in the next couple of hours by observing current atmospheric conditions, and analysing hundreds of historical storms.

Now, thanks to a recent breakthrough by UKCEH scientists, they can make these short-term forecasts, known as ‘nowcasts’, for six hours ahead and with a higher degree of accuracy. The new research found drier soils can increase the intensity of storms when they are on the move, affecting where they travel and the amount of rainfall they produce.

These novel nowcasting predictions and related satellite observations for West Africa are available via UKCEH’s new free portal, which has been funded by the Natural Environment Research Council (NERC).

National forecasters can interpret the data and make localised forecasts, sending out warnings to people in areas that are expected to be hit by a storm. Last year, as part of a trial of the nowcasting tool, forecasters in Senegal used it to issue a severe weather warning to the public via text message.

Dr Steven Cole of UKCEH says: “The portal is a great example of how new scientific understanding can be translated into useable real-time tools by working with forecasters. Importantly, this will support communities in West Africa to better manage flood risk from intense rainfall.”

A recent study** found that using data about land surface temperatures improves predictions about the path and strength of an approaching mesoscale convective system (MCS) up to 12 hours ahead. These ‘megastorms’ can be bigger than the size of England and unleash over 100mm of rainfall in just an hour.

“We found a surprising level of predictability of storms from land surface temperatures when testing our methodology on historical data, and West African forecasters are finding our approach very useful for their work,” says Professor Chris Taylor of UKCEH.

“We would expect mesoscale convective systems elsewhere in the world to also be influenced by drier soils. Therefore, our methodology could potentially be used to improve storm and flood warning systems in tropical regions such as South Asia and Australia, as well as parts of USA and South America.”

The new nowcasting portal allows forecasters to observe storm clouds in near real-time via satellite and compare them with historical storm behaviour, plus view data on current land surface conditions. The online tool then uses these data, updated every 15 minutes, to calculate the probability of a mesoscale convective system reaching different areas of the Sahel between the current time and six hours ahead.

UKCEH scientists are continuing to work with forecasting services in West Africa to increase the advance warning time and its reliability by combining more factors influencing storm behaviour within their nowcast modelling, in addition to land surface temperature. These include soil moisture, atmospheric humidity, wind conditions and the amount of rainfall there has been in preceding days.

As part of a collaboration with ANACIM, the national meteorological service in Senegal, UKCEH has also developed short-term forecasts of potential flood impacts and risk in Dakar which are available on the portal. It also hopes to work with other forecasting services to provide this service for other areas.

-Ends-

Notes to Editors
The new nowcasting portal has been produced as part of UKCEH’s Land Air Water International Science (LAWIS) programme funded by NERC, part of UK Research and Innovation (UKRI), and follows work carried out in other projects in West Africa. These include GCRF African SWIFT, supported by UKRI’s Global Challenges Research Fund, and Nowcasting Flood Impacts of Convective storms in the Sahel (NFLICS), funded by NERC and the Foreign, Commonwealth and Development Office.
Forecasters and researchers can apply for access to real-time data from the portal by emailing nowcasting-portal@ceh.ac.uk

*UKCEH has been carrying out climate research in West Africa for several years, in order to support improved forecasting that will enable better decision making by town planners, farmers and communities. A study led by Professor Chris Taylor, published in the journal Nature in 2017, found extreme storms in the Sahel have tripled over the past 30 years due to global warming (DOI: 10.1038/nature22069).

**Taylor et al. 2022. Nowcasting tracks of severe convective storms in West Africa from observations of land surface state. Environmental Research Letters. DOI: 10.1088/1748-9326/ac536d

About the UK Centre for Ecology & Hydrology (UKCEH)
The UK Centre for Ecology & Hydrology is a centre for excellence in environmental science across water, land and air. Our 500 scientists work to understand the environment, how it sustains life and the human impact on it – so that together, people and nature can prosper. We have a long history of investigating, monitoring and modelling environmental change, and our science makes a positive difference in the world.

The UK Centre for Ecology & Hydrology is a strategic delivery partner for the Natural Environment Research Council, part of UK Research and Innovation.

www.ceh.ac.uk / Twitter: @UK_CEH / LinkedIn: UK Centre for Ecology & Hydrology

Taste of the future: Robot chef learns to ‘taste as you go’

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

Robot chef learns to 'taste as you go' 

VIDEO: THIS ROBOT 'CHEF' IS LEARNING TO BE A BETTER COOK BY 'TASTING' THE SALTINESS OF A SIMPLE DISH OF EGGS AND TOMATOES AT DIFFERENT STAGES OF THE COOKING PROCESS, IMITATING A SIMILAR PROCESS IN HUMANS. view more 

CREDIT: BIO-INSPIRED ROBOTICS LABORATORY, UNIVERSITY OF CAMBRIDGE

A robot ‘chef’ has been trained to taste food at different stages of the chewing process to assess whether it’s sufficiently seasoned.

Working in collaboration with domestic appliances manufacturer Beko, researchers from the University of Cambridge trained their robot chef to assess the saltiness of a dish at different stages of the chewing process, imitating a similar process in humans.

Their results could be useful in the development of automated or semi-automated food preparation by helping robots to learn what tastes good and what doesn’t, making them better cooks.

When we chew our food, we notice a change in texture and taste. For example, biting into a fresh tomato at the height of summer will release juices, and as we chew, releasing both saliva and digestive enzymes, our perception of the tomato’s flavour will change.

The robot chef, which has already been trained to make omelettes based on human taster’s feedback, tasted nine different variations of a simple dish of scrambled eggs and tomatoes at three different stages of the chewing process, and produced ‘taste maps’ of the different dishes.

The researchers found that this ‘taste as you go’ approach significantly improved the robot’s ability to quickly and accurately assess the saltiness of the dish over other electronic tasting technologies, which only test a single homogenised sample. The results are reported in the journal Frontiers in Robotics & AI.

The perception of taste is a complex process in humans that has evolved over millions of years: the appearance, smell, texture and temperature of food all affect how we perceive taste; the saliva produced during chewing helps carry chemical compounds in food to taste receptors mostly on the tongue; and the signals from taste receptors are passed to the brain. Once our brains are aware of the flavour, we decide whether we enjoy the food or not.

Taste is also highly individual: some people love spicy food, while others have a sweet tooth. A good cook, whether amateur or professional, relies on their sense of taste, and can balance the various flavours within a dish to make a well-rounded final product.

“Most home cooks will be familiar with the concept of tasting as you go – checking a dish throughout the cooking process to check whether the balance of flavours is right,” said Grzegorz Sochacki from Cambridge’s Department of Engineering, the paper’s first author. “If robots are to be used for certain aspects of food preparation, it’s important that they are able to ‘taste’ what they’re cooking.”

“When we taste, the process of chewing also provides continuous feedback to our brains,” said co-author Dr Arsen Abdulali, also from the Department of Engineering. “Current methods of electronic testing only take a single snapshot from a homogenised sample, so we wanted to replicate a more realistic process of chewing and tasting in a robotic system, which should result in a tastier end product.”

The researchers are members of Cambridge’s Bio-Inspired Robotics Laboratory run by Professor Fumiya Iida of the Department of Engineering, which focuses on training robots to carry out the so-called last metre problems which humans find easy, but robots find difficult. Cooking is one of these tasks: earlier tests with their robot ‘chef’ have produced a passable omelette using feedback from human tasters.

“We needed something cheap, small and fast to add to our robot so it could do the tasting: it needed to be cheap enough to use in a kitchen, small enough for a robot, and fast enough to use while cooking,” said Sochacki.

To imitate the human process of chewing and tasting in their robot chef, the researchers attached a conductance probe, which acts as a salinity sensor, to a robot arm. They prepared scrambled eggs and tomatoes, varying the number of tomatoes and the amount of salt in each dish.

CAPTION

The robot chef, which has already been trained to make omelettes based on human taster’s feedback, tasted nine different variations of a simple dish of scrambled eggs and tomatoes at three different stages of the chewing process, and produced ‘taste maps’ of the different dishes. The researchers found that this ‘taste as you go’ approach significantly improved the robot’s ability to quickly and accurately assess the saltiness of the dish over other electronic tasting technologies.

CREDIT

Bio-Inspired Robotics Laboratory, University of Cambridge

Using the probe, the robot ‘tasted’ the dishes in a grid-like fashion, returning a reading in just a few seconds.

To imitate the change in texture caused by chewing, the team then put the egg mixture in a blender and had the robot test the dish again. The different readings at different points of ‘chewing’ produced taste maps of each dish.

Their results showed a significant improvement in the ability of robots to assess saltiness over other electronic tasting methods, which are often time-consuming and only provide a single reading.

While their technique is a proof of concept, the researchers say that by imitating the human processes of chewing and tasting, robots will eventually be able to produce food that humans will enjoy and could be tweaked according to individual tastes.

“When a robot is learning how to cook, like any other cook, it needs indications of how well it did,” said Abdulali. “We want the robots to understand the concept of taste, which will make them better cooks. In our experiment, the robot can ‘see’ the difference in the food as it’s chewed, which improves its ability to taste.”

“Beko has a vision to bring robots to the home environment which are safe and easy to use,” said Dr Muhammad W. Chughtai, Senior Scientist at Beko plc. “We believe that the development of robotic chefs will play a major role in busy households and assisted living homes in the future. This result is a leap forward in robotic cooking, and by using machine and deep learning algorithms, mastication will help robot chefs adjust taste for different dishes and users.”

In future, the researchers are looking to improve the robot chef so it can taste different types of food and improve sensing capabilities so it can taste sweet or oily food, for example.

The research was supported in part by Beko plc and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI). Fumiya Iida is a Fellow of Corpus Christi College, Cambridge.

CAPTION

Eggs and tomatoes made by a human cook

Indigenous peoples have shucked billions of oysters around the world sustainably

Global study of indigenous oyster fisheries finds evidence of huge harvests spanning hundreds and even thousands of years

Peer-Reviewed Publication

SMITHSONIAN

Eroding archaeological site on Maryland’s Eastern Shore 

IMAGE: ERODING ARCHAEOLOGICAL SITE ON MARYLAND’S EASTERN SHORE. SITES LIKE THIS CONTAIN MASSIVE QUANTITIES OF OYSTERS HARVESTED OVER 1,000 YEARS AGO AND WERE KEY TO FORMING THE FOUNDATION FOR THIS STUDY. THE DENSE ACCUMULATION OF OYSTERS ARE ALL ARCHAEOLOGICAL OYSTERS DATED TO OVER A MILLENNIA AGO, WITH INTACT DEPOSITS LYING UNDERNEATH THE MARSH TO THE RIGHT. A NEW GLOBAL STUDY OF INDIGENOUS OYSTER FISHERIES CO-LED BY SMITHSONIAN’S NATIONAL MUSEUM OF NATURAL HISTORY ANTHROPOLOGIST TORBEN RICK AND TEMPLE UNIVERSITY ANTHROPOLOGIST AND FORMER SMITHSONIAN POSTDOCTORAL FELLOW LESLIE REEDER-MYERS SHOWS THAT OYSTER FISHERIES WERE HUGELY PRODUCTIVE AND SUSTAINABLY MANAGED ON A MASSIVE SCALE OVER HUNDREDS AND EVEN THOUSANDS OF YEARS OF INTENSIVE HARVEST. THE STUDY’S BROADEST FINDING WAS THAT LONG BEFORE EUROPEAN COLONIZERS ARRIVED, THE INDIGENOUS GROUPS IN THESE LOCATIONS HARVESTED AND ATE IMMENSE QUANTITIES OF OYSTERS IN A MANNER THAT DID NOT APPEAR TO CAUSE THE BIVALVES’ POPULATIONS TO SUFFER AND CRASH. view more 

CREDIT: TORBEN RICK

A new global study of Indigenous oyster fisheries co-led by Smithsonian’s National Museum of Natural History anthropologist Torben Rick and Temple University anthropologist and former Smithsonian postdoctoral fellow Leslie Reeder-Myers shows that oyster fisheries were hugely productive and sustainably managed on a massive scale over hundreds and even thousands of years of intensive harvest. The study’s broadest finding was that long before European colonizers arrived, the Indigenous groups in these locations harvested and ate immense quantities of oysters in a manner that did not appear to cause the bivalves’ populations to suffer and crash.

The research, published May 3 in Nature Communications, suggests that studying these ancient, sustainable fisheries offers insights to help restore and manage estuaries today. Further, the authors write that these findings make plain that Indigenous peoples in these locations had deep connections to oysters and that their living descendants are long overdue to be involved in decisions about how to manage what is left of this precious coastal resource.

In places like the Chesapeake Bay, San Francisco Bay and Botany Bay near Sydney, oysters exist at tiny fractions of their former numbers. Oyster numbers declined in these places due to boom and bust exploitation—beginning with European colonizers establishing commercial fisheries that quickly raked in huge quantities of oysters, and ending with cratering oyster populations that were also being devastated by habitat alteration, disease and introduced species.

But these parables of ecological collapse wrought by colonization and capitalism often omit evidence of Indigenous fisheries that predated those of European settlers by thousands of years.

Rick said the new paper expands on a seminal 2004 paper that documented the collapses of 28 oyster fisheries located along the east and west coasts of North America and Australia’s east coast. But the 2004 paper’s timeline in each location begins with European colonists’ creation of commercial oyster fisheries.

The new study’s goal was to deepen the historical context of those modern declines by documenting the Indigenous oyster fisheries at the same locales that appeared in the 2004 paper. But stretching this ecological timeline deeper into the past was not the paper’s only aim, Rick said.

“Conservation today can’t just be seen as a biological question and can’t just be about undoing the environmental damage we’ve done in the modern era,” Rick said. “Instead, global conservation efforts should be coupled with undoing the legacies of colonialism which brought about the attempted erasure and displacement of Indigenous people all over the world.”

To document the Indigenous oyster fisheries in the same locations from the 2004 paper, Rick, Reeder-Myers and colleagues turned to the archaeological record, specifically to accumulations of oyster shells that are also known as middens. These middens come in many forms and are much more than trash piles as some archeologists once suggested. Some were small and perhaps only used seasonally, while others were monumental, towering up to 30 feet into the sky, serving as important ceremonial, sacred and symbolic spaces.

Rick and Reeder-Myers assembled a team of 24 other researchers who specialized in the relevant archaeological sites to gather all the data they could on these Indigenous oyster fisheries. These data came from published academic papers, gray literature (research not made readily available for publication) and the team’s own research.


CAPTION

Dense shell midden deposit spanning the past 1,000 years as exposed during excavation at a Tseshaht First Nation village in the Pacific Northwest. A new global study of Indigenous oyster fisheries co-led by Smithsonian’s National Museum of Natural History anthropologist Torben Rick and Temple University anthropologist and former Smithsonian postdoctoral fellow Leslie Reeder-Myers shows that oyster fisheries were hugely productive and sustainably managed on a massive scale over hundreds and even thousands of years of intensive harvest. The study’s broadest finding was that long before European colonizers arrived, the Indigenous groups in these locations harvested and ate immense quantities of oysters in a manner that did not appear to cause the bivalves’ populations to suffer and crash.

CREDIT

Iain McKechnie


After creating what amounted to a massive spreadsheet for these North American and Australian sites, the researchers assessed which pieces of information were available for the greatest number of locations and realized that the weight of the oyster shells or the number of individual oysters at a site were the two data sets that were most consistent.  

“Oyster harvesting didn’t start 500 years ago with the arrival of Europeans,” said study co-author Bonnie Newsom, an anthropologist at the University of Maine and citizen of the Penobscot Indian Nation. “Indigenous peoples had a relationship with and understood this species well enough to use it as part of their subsistence and cultural practices. Indigenous peoples have a lot to offer in terms of how to engage with this natural resource in ways that are sustainable.”

In North America, the highest single site totals come from Florida’s Gulf Coast. The study estimates that an island called Mound Key in Estero Bay contains the shells of some 18.6 billion oysters harvested by the region’s Calusa tribe. About 200 miles north in Cedar Key, Florida, a site known simply as Shell Mound features the remains of an estimated 2.1 billion oysters. On the Atlantic coast of the United States, the midden at South Carolina’s Fig Island boasts just under 75.6 million oysters, and a number of sites in the Chesapeake Bay total around 84 million of the shellfish remains. In Australia, Saint Helena Island near Brisbane is estimated to contain roughly 50 million oyster shells harvested by Indigenous peoples over more than 1,000 years.

“We knew there were big sites in the southern U.S., but when we started to calculate just how many oysters were in these sites we were astonished,” Rick said.

Some of the oldest oyster middens are found in California and Massachusetts and date back more than 6,000 years. The longest-utilized single sites (though not necessarily with perfect continuity) span some 5,000 years. 

CAPTION

Crystal River site in Florida with massive shell mounds, dominated by oysters, pictured here during archaeological mapping and showing the modern staircase and platform built on top of one of the mounds. A new global study of Indigenous oyster fisheries co-led by Smithsonian’s National Museum of Natural History anthropologist Torben Rick and Temple University anthropologist and former Smithsonian postdoctoral fellow Leslie Reeder-Myers shows that oyster fisheries were hugely productive and sustainably managed on a massive scale over hundreds and even thousands of years of intensive harvest. The study’s broadest finding was that long before European colonizers arrived, the Indigenous groups in these locations harvested and ate immense quantities of oysters in a manner that did not appear to cause the bivalves’ populations to suffer and crash.

CREDIT

Victor Thompson

In many of these places, prior studies have suggested that Indigenous harvests remained sustainable despite their long tenure and significant numbers. The most common way of determining this, Rick said, is by looking for changes in the oysters’ shell sizes in the middens. If the fishery is overextended, the shells tend to get smaller. But studies of Indigenous oyster fisheries have not found widespread evidence of this shrinking shell pattern, suggesting the shellfish populations were generally healthy.

“The fact that there are so many oysters at archaeological sites in so many different regions is an important lesson,” said Reeder-Myers. “These systems have a ton of potential and huge quantities of oysters can be sustainably harvested over long time periods if the ecosystem is healthy.”

Rick said he hopes that their findings are heeded by biologists and environmental managers and heighten public awareness about the deep connections of Indigenous peoples to coastal ecosystems around the world.

“What this study does is it says we need to start a broader dialogue when we look to restore an ecosystem or make conservation decisions,” Rick said. “In this case, that dialogue needs to include the Indigenous peoples whose ancestors stewarded these ecosystems for millennia. This broadening of perspectives can enhance biological conservation and help restore connections between Indigenous peoples and their ancestral homelands.”

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Green roofs are worth the cost for urban residents

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

green roofs in Portland, Oregon 

IMAGE: GREEN ROOFTOPS IN PORTLAND, OREGON view more 

CREDIT: NOELWAH NETUSIL.

URBANA, Ill. ­– Plant-covered roofs have become a regular sight in Portland, Oregon. The city is a leader in incorporating green infrastructure for stormwater management, including free street trees, rebates for small residential housing footprints, and green roofs.

Green roofs, also known as rooftop gardens or ecoroofs, typically have a layer of plants growing in soil on top of the roof, as well as material for waterproofing, structural support, and insulation. A new study from Reed College in collaboration with the University of Illinois and Portland State University explores the benefits of green roofs and how much Portland residents are willing to pay to increase the number of green roofs across the city.

“Countries around the world are investing significant public resources to reduce the impact of stormwater runoff,” explains Amy Ando, professor of agricultural and consumer economics at U of I, and a co-author on the study. “Green roofs are part of that solution because they capture some of the rain that would otherwise end up in sewage systems. Knowing the benefits from investing in green roofs is important for implementing sound public policies.”

The study investigates how much people would pay for benefits that include reduced sewer overflow events (CSOs), reduced urban heat island effect, and increased presence of pollinators like bees and butterflies. Like many cities, extreme rainfall events in Portland can quickly overwhelm old sewer systems and lead to flooding, which impacts water quality as well as transportation and properties.

“Although CSO events have declined dramatically in Portland after a major system upgrade ($1.4 billion “Big Pipe Project”), they still happen,” says Noelwah Netusil, professor of economics at Reed College and lead author on the paper. “Our findings show that survey respondents place the largest value on reducing CSO events further and are willing to support additional funding for this.”

Since 2018, the city of Portland has required new buildings in the central city with a footprint over 20,000 square feet to have an ecoroof covering 100% of the area (minus a few exceptions like solar panels and evacuation routes) to further protect the city from flooding. Most green roofs are concentrated in the city center, covering 1.4 million square feet.

Survey respondents indicated how much they would pay for a green roof to result in a scale of benefits. For example, it would cost more to decrease sewer overflows three times per year rather than two, lower the air temperature by over one degree rather than half a degree, and bring in a significant amount of bees, birds, and butterflies rather than keep pollinators at the same level.

For green roofs to reduce average temperatures by more than 1 degree Fahrenheit, reduce sewer overflows by three per year, and increase pollinators by 150%, respondents were willing to pay $442.40 per household. That amounts to $116.8 million for the city of Portland. For green roofs to reduce summer temperatures by less than 0.5 degrees, reduce sewer overflow by one, and increase pollinators by 50%, residents were willing to pay $202.40 per household or $54.4 million total for Portland. The cost would be added in monthly installments to their sewage and stormwater utility bill for one year and green roofs would be installed a year after the program was fully funded. 

While survey respondents who had visited or seen a green roof had the highest estimated willingness to pay to support the program described in the survey, respondents who knew nothing about green roofs prior to taking the survey were still supportive of the green roof program. Furthermore, people generally preferred ecoroofs to be more equally spread out across the city rather than concentrated in the city center.

“Reducing CSO events had the largest value for all survey respondents – whether they had visited, seen, heard, or knew nothing about green roofs prior to taking the survey,” Netusil explains. “The total estimated benefits from the programs we examined would be sufficient to more than double the number of green roofs on commercial and industrial properties in our study area (Portland).”

Eliana Brown, University of Illinois Extension and Illinois-Indiana Sea Grant water quality specialist, says the study’s results will be included on a new green stormwater infrastructure website.

“When municipalities in Illinois contact us because they’re interested in applying green infrastructure, they want to know how the public will benefit from their investment,” Brown states. “This new research on green roofs goes beyond Portland, giving gives stormwater professionals more tools to advocate for practices that are valuable for communities across Illinois and elsewhere.” 

The paper, “Valuing the public benefits of green roofs,” is published in Landscape and Urban Planning [https://doi.org/10.1016/j.landurbplan.2022.104426]. Authors include Noelwah Netusil, Lauren Lavelle, Sahan Dissanayake, and Amy Ando.

The research is funded by the Bernard Goldhammer Grant for Research on Economics and Natural Resources, Reed College and the Stendal Fund for Economics, Reed College. This paper is also based in part on work funded by the USDA-NIFA W4133 Multistate Research Grant 1008843.

A Concordia-made tool assessing indoor COVID-19 transmission risks expands across North America

Leon Wang’s web tool CityRPI can help locals determine the risks of airborne infection using customizable assessments based on building type and mitigation measures

Peer-Reviewed Publication

CONCORDIA UNIVERSITY

Leon Wang 

IMAGE: LEON WANG: “WE NEED TO EVALUATE WHICH STRATEGIES ARE MOST EFFECTIVE ON A CASE-BY-CASE, BUILDING-BY-BUILDING BASIS.” view more 

CREDIT: CONCORDIA UNIVERSITY

It is becoming increasingly likely that humanity will have to learn to live with COVID-19. But that does not mean we should be letting our guards down or ignoring the way it spreads throughout the population.

As our understanding of the virus’s transmissibility increases, so too does the range of tools available to mitigate it. Among them is the City Reduced Probability of Infection (CityRPI), a web-based tool developed by Leon Wang. The associate professor of building, civil and environmental engineering at the Gina Cody School of Engineering and Computer Science came up with it alongside his PhD students Ali Katal and Maher Albettar. Originally unveiled in the fall of 2020, CityRPI — pronounced “City-R-Pi”— calculates the probability of COVID-19 infection through aerosol transmission in indoor spaces in Montreal.

In a new paper published in the journal Sustainable Cities and Society, Katal, Wang and Albettar show how their tool can be expanded to project this likelihood in cities across North America. The site’s scope grew as the initial project became better known across Canada and the United States and the initial development team began collaborations with other researchers.

CityRPI relies on technical data such as air exchange rates, ventilation and air filtration conditions provided by local users to determine transmission likelihood. Specific building types such as offices, university buildings or retail stores are added to make results even more customizable. So too are in-place mitigating efforts, for instance the wearing of facemasks, the presence of new air filtration systems, reducing time spent on location, opening windows and more. Data of daily COVID-19 cases is provided in real time.

This, the researchers say, can help health officials and the public compare strategies to curb indoor transmission risks as health restrictions loosen and in-person socialization resumes.


CAPTION

CityRPI screen shot

CREDIT

Leon Wang

Different solutions for different buildings

Besides getting fully vaccinated, the wearing of facemasks is still the single most effective method of cutting down the transmission of COVID-19. But as Wang notes, there is a range of complementary strategies that can also be used to reduce the risk even further – but not all of them are equally effective in all types of buildings.

“As we see on the website, each building is different,” he says. “And so the risks associated with each are different. The effectiveness of different strategies should not be evaluated only in an absolute sense. We need to evaluate which strategies are most effective on a case-by-case, building-by-building basis. An air purifier may be very effective in a classroom, but much less so in a large indoor space like a concert hall.”

Wang does not think CityRPI’s potential ends with buildings. He envisions several other functionalities: one example is developing a method of calculating dynamic mitigation and risk assessment based on an individual’s daily movements, allowing them to identify potential exposure during their daily commute; another is using public data to assess CO2 levels and report ventilation conditions in local schools. It can also be adapted to track other airborne viral transmissions.

“The website can be extended to provide information not only about COVID but also, for example, influenza,” he says. “The methodology is similar. We would be able to provide some guidelines and inputs for those who want to reduce their chances of catching the flu or other airborne diseases.”

This research was supported by the Natural Sciences and Engineering Research Council of Canada and the Advancing Climate Change Science in Canada Program.

Read the cited paper: “A real-time web tool for monitoring and mitigating indoor airborne COVID-19 transmission risks at city scale

Hidden benefit: Facemasks may reduce severity of COVID-19 and pressure on health systems, researchers find


Peer-Reviewed Publication

MCMASTER UNIVERSITY

Masks 

IMAGE: A NEW MATHEMATICAL MODEL SUGGESTS EFFECTIVE MASKING COULD DRASTICALLY SLOW THE SPREAD OF COVID-19. view more 

CREDIT: MCMASTER UNIVERSITY, HAMILTON, ONTARIO, CANADA

HAMILTON, May 4, 2022 — McMaster University researchers who study the dynamics of infectious disease transmission have investigated the population-level consequences of a potentially significant––and unobvious––benefit of wearing masks.

For the study, the researchers developed a model to investigate COVID-19 “variolation”––an incidental but potentially beneficial form of immunization achieved by inhaling smaller doses of the virus than would be inhaled without a mask.

A form of variolation was deliberately used in the 18th century to control smallpox. It involved infecting a healthy individual with small doses of the live virus taken from a dried scab or pustule of a person infected with smallpox.  Variolated individuals often experienced far less severe disease than those who were infected naturally, but nevertheless were immune to further infection.

Early in the COVID-19 pandemic, it was suggested that people who were infected while masked might experience mild illness and could be considered “variolated”.

The new mathematical model allows researchers to estimate the potential impact of this effect on the population as a whole.

“If the variolation effect is strong, then the number of severe cases, and consequently pressure on health-care systems, could be substantially reduced if most people wear masks –– even if masks don't prevent them from being infected,” says senior author David Earn, Faculty of Science Research Chair in Mathematical Epidemiology and Professor of Mathematics at McMaster and Canada’s Global Nexus for Pandemics & Biological Threats.

The model suggests effective masking could drastically slow the spread of COVID-19, reduce the magnitude of the pandemic peak by “flattening the curve,” and reduce the prevalence of severe cases from that point forward.

“Our qualitative findings are that the value of masking is under-appreciated in a public health context, especially as COVID-19 transitions from pandemic to endemic, and we should think twice about getting rid of mask mandates,” says Zachary Levine, lead author of the study and a former undergraduate in the Arts and Science programme at McMaster. Levine is now a graduate student at the Weizmann Institute of Science in Israel. 

“As we prepare for the next pandemic, understanding how different infection control strategies could affect disease dynamics could help us understand which policies are worth pursuing,” he says.

The results of this research are potentially applicable to any respiratory infection that is transmitted by inhaling infectious particles. For future COVID variants or other infectious diseases, the model can be used to study how increasing the proportion of mild cases affects the overall dynamics of disease spread.

“If wearing a mask protects you in addition to those in the room around you, it could also have significant impacts for everyone who may not be in the room,” says Levine.

The study was published online in the Journal of the Royal Society Interface.

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