Groundbreaking AI Research

Technion researchers are harnessing the power of artificial intelligence (AI) to tackle the world’s most-pressing challenges. Their extensive work in the field has positioned the Technion among the world’s leaders in AI research and development. CSRankings, the leading metrics-based ranking of top computer science institutions around the world, has ranked the Technion No. 1 in the field of artificial intelligence in Europe, and 15th worldwide.

In the subfield of machine learning, the Technion is ranked 11th worldwide. Over the years, the Technion has carried out outstanding research in the field of AI – much of which has developed into trailblazing commercial products. Collaborations with manufacturers, the high-tech industry, government agencies, R&D centers, healthcare providers and academic institutions, have all contributed to the Technion’s excellence in the field, and many alumni and researchers have gone on to found companies across the AI spectrum.

Technion AI Brochure – Fall 2021 Edition

During the coronavirus pandemic, Technion researchers and alumni have used a host of AI technologies, from detection to diagnostics, including testing for pre-symptomatic COVID-19 carriers; predicting the spread of COVID-19 around the globe; and analyzing the data of thousands of patients to show the effectiveness of the COVID-19 vaccine.

To learn about the Technion’s trailblazing AI research and technologies, click to read our Fall  2021 AI Brochure.

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AI Predicts Heart Conditions

What if a computer told you that you were going to develop a heart condition in five years? You would have time to change your lifestyle, and perhaps mitigate or avoid the condition. A team of Technion researchers taught a computer to do just that.

Shany Biton and Sheina Gendelman, two M.Sc. students working under the supervision of Assistant  Professor Joachim A. Behar, head of the Artificial Intelligence in Medicine laboratory (AIMLab.) in the Technion Faculty of Biomedical Engineering, wrote a machine learning algorithm capable of accurately predicting whether a patient will develop atrial fibrillation within five years. Conceptually, the researchers sought to find out whether a machine learning algorithm could capture patterns predictive of atrial fibrillation even though there was no atrial fibrillation diagnosed by a human cardiologist at the time.
AIMLab.
AIMLab.

Atrial fibrillation is an abnormal heart rhythm that is not immediately life-threatening, but significantly increases patients’ risk of stroke and death. Warning patients that they are at risk of developing it can give them time to change their lifestyle and avoid or postpone the onset of the condition. It may also encourage regular follow-ups with the patient’s cardiologist, ensuring that if and when the condition develops, it will be identified quickly, and treatment will be started without delay. Known risk factors for atrial fibrillation include sedentary lifestyle, obesity, smoking, genetic predisposition, and more.

Prof. Joachim Behar
Prof. Joachim Behar

Ms. Biton and Ms. Gendelman used more than one million 12-lead ECG recordings from more than 400,000 patients to train a deep neural network to recognize patients at risk of developing atrial fibrillation within 5 years. Then, they combined the deep neural network with clinical information about the patient, including some of the known risk factors. Both the ECG recordings and the patients’ electronic health record were provided by the Telehealth Network of Minas Gerais (TNMG), a public telehealth system assisting 811 of the 853 municipalities in the state of Minas Gerais, Brazil. The resulting machine learning model was able to correctly predict the development of atrial fibrillation risk in 60% of cases, while preserving a high specificity of 95%, meaning that only 5% of persons identified as being potentially at risk did not develop the condition.

“We do not seek to replace the human doctor – we don’t think that would be desirable,” said Prof. Behar of the results, “but we wish to put better decision support tools into the doctors’ hands. Computers are better equipped to process some forms of data. For example, examining an ECG recording today, a cardiologist would be looking for specific features which are known to be associated with a particular disease. Our model, on the other hand, can look for and identify patterns on its own, including patterns that might not be intelligible to the human eye.”

Doctors have progressed from taking a patient’s pulse manually, to using a statoscope, and then the ECG. Using machine learning to assist the analysis of ECG recordings could be the next step on that road.

Since ECG is a low-cost routine test, the machine learning model could easily be incorporated into clinical practice and improve healthcare management for many individuals. Access to more patients’ datasets would let the algorithm get progressively better as a risk prediction tool. The model could also be adapted to predict other cardiovascular conditions.

Shany Biton
Shany Biton
Sheina Gendelman
Sheina Gendelman

 

 

 

 

 

 

 

The study was conducted in collaboration with Antônio Ribeiro from the Uppsala University, Sweden and Gabriela Miana, Carla Moreira, Antonio Luiz Ribeiro from the Universidade Federal de Minas Gerais, Brazil.

The study was published in the European Heart Journal – Digital Health

Check out our AI Brochure

Tiny Lasers Acting Together as One

Israeli and German researchers have developed a way to force an array of vertical cavity lasers to act together as a single laser – a highly effective laser network the size of a grain of sand. The findings are presented in a new joint research paper that was published online by Science on Friday, September 24.

Cell phones, car sensors, or data transmission in fiber optic networks all use so called Vertical-Cavity Surface-Emitting Lasers (VCSELs) – semiconductor lasers that are firmly anchored in our everyday technology. Though widely used, the VCSEL device has miniscule size of only a few microns, which sets a stringent limit on the output power it can generate. For years, scientists have sought to enhance the power emitted by such devices through combining many tiny VCSELs and forcing them to act as a single coherent laser, but with limited success. The current breakthrough uses a different scheme: it employs a unique geometrical arrangement of VCSELs on the chip that forces the flight to flow in a specific path – a photonic topological insulator platform.

From topological insulators to topological lasers

Topological insulators are revolutionary quantum materials that insulate on the inside but conduct electricity on their surface, without loss. Several years ago, the Technion group led by Distinguished Professor Mordechai (Moti) Segev introduced these innovative ideas into photonics, and demonstrated the first Photonic Topological Insulator, where light travels around the edges of a two-dimensional array of waveguides without being affected by defects or disorder. This opened a new field, now known as “Topological Photonics,” where hundreds of groups currently have active research. In 2018, the Technion group also found a way to use the properties of photonic topological insulators to force many micro-ring lasers to lock together and act as a single laser. But that system still had a major bottleneck: the light was circulating in the photonic chip confined to the same plane used for extracting the light. That meant that the whole system was again subject to a power limit, imposed by the device used to get the light out, similar to having a single socket for a whole power plant. The current breakthrough uses a different scheme: the lasers are forced to lock within the planar chip, but the light is now emitted through the surface of the chip from each tiny laser and can be easily collected.

Circumstances and participants

This German-Israeli research project originated primarily during the Corona pandemic. Without the enormous commitment of the researchers involved, this scientific milestone would not have been possible. The research was conducted by PhD student Alex Dikopoltsev from the team of Distinguished Professor Mordechai (Moti) Segev of Technion’s Physics and Electrical & Computer Engineering Faculties, the Solid State Institute and the Russell Berrie Nanotechnology Institute at the Technion – Israel Institute of Technology, and Ph.D. student Tristan H. Harder from the team of Professor Sebastian Klembt and Professor Sven Höfling at the Chair of Applied Physics at the University of Würzburg, and the Cluster of Excellence ct.qmat – Complexity and Topology in Quantum Materials, in collaboration with researchers from Jena and Oldenburg. The device fabrication took advantage of the excellent clean room facilities at the University of Würzburg.

The long road to new topological lasers

“It is fascinating to see how science evolves,” said Distinguished Professor Moti Segev, the Dr. Robert J. Shillman Distinguished Professor of Physics and Electrical & Computer Engineering at the Technion. “We went from fundamental physics concepts to foundational changes therein, and now to real technology that is now being pursued by companies. Back in 2015, when we started to work on topological insulator lasers, nobody believed it was possible, because the topological concepts known at that time were limited to systems that do not, in fact, cannot, have gain. But all lasers require gain. So topological insulator lasers stood against everything known at that time. We were like a bunch of lunatics searching for something that was considered impossible. And now we have made a large step towards real technology that has many applications.”

פרופ'-מחקר מוטי שגב
Distinguished Professor Moti Segev

The Israeli and German team utilized the concepts of topological photonics with VCSELs that emit the light vertically, while the topological process responsible for the mutual coherence and locking of the VCSELs occurs in the plane of the chip. The end result is a powerful but very compact and efficient laser, not limited by a number of VCSEL emitters, and undisturbed by defects or altering temperatures.

“The topological principle of this laser can generally work for all wavelengths and thus a range of materials,” explains German project leader Prof. Sebastian Klembt of the University of Würzburg, who is working on light-matter interaction and topological photonics within the ct.qmat cluster of excellence. “Exactly how many micro-lasers need to be arranged and connected would always depend entirely on the application. We can expand the size of the laser network to a very large size, and in principle it will remain coherent also for large numbers. It is great to see that topology, originally a branch of mathematics, has emerged as a revolutionary new toolbox for controlling, steering and improving laser properties.”

The groundbreaking research has demonstrated that it is in fact theoretically and experimentally possible to combine VCSELs to achieve a more robust and highly efficient laser. As such, the results of the study pave the way towards applications of numerous future technologies such as medical devices, communications, and a variety of real-world applications.

Click here for the paper in Science.

3D-Printing Blood Vessel Networks

Researchers led by Technion Professor Shulamit Levenberg, who specializes in tissue engineering, have succeeded in creating a hierarchical blood vessel network, necessary for supplying blood to implanted tissue. In the study, recently published in Advanced Materials, Dr. Ariel Alejandro Szklanny used 3D printing for creating big and small blood vessels to form for the first time a system that contained a functional combination of both. The breakthrough took place in Prof. Levenberg’s Stem Cell and Tissue Engineering Laboratory in the Technion’s Faculty of Biomedical Engineering.

Professor Shulamit Levenberg
Professor Shulamit Levenberg

In the human body, the heart pumps blood into the aorta, which then branches out into progressively smaller blood vessels, transporting oxygen and nutrients to all the tissues and organs. Transplanted tissues need similar support of blood vessels, and consequently so do tissues engineered for transplantation. Until now, experiments with engineered tissue containing hierarchical vessel networks have involved an intermediary step of transplanting first into a healthy limb, allowing the tissue to be permeated by the host’s blood vessels, and then transplanting the structure into the affected area. (e.g. this study by Idan Redenski about engineered bone grafts, published earlier this year.) With Dr. Szklanny’s new achievement, the intermediary step might become unnecessary.

An important step towards personalized medicine

To create in the lab a tissue flap with all the vessels necessary for blood supply, Dr. Szklanny combined and expanded on two separate techniques. First, he created a fenestrated polymeric scaffold that mimics the large blood vessel, using 3D printing technologies. The fenestration served to create not just a hollow tube, but a tube with side openings that allowed the connection of smaller vessels to the engineered larger vessel. Using a collagen bio-ink, tissue was then printed and assembled around that scaffold, and a network of tiny blood vessels formed within. Finally, the large vessel scaffold was covered with endothelial cells, which are the type of cells that constitute the inner layer of all blood vessels in the body. After a week of incubation, the artificial endothelium created a functional connection with the smaller 3D bio-printed vessels, mimicking the hierarchical structure of the human blood vessel tree.

The resulting structure was then implanted in a rat, attached to its femoral artery. Blood flowing through it did what we would want blood to do: it spread through the vessel network, reaching to the ends of the structure, and supplied blood to the tissue without leaking from the blood vessels.

One interesting point to note is that while previous studies used collagen from animals to form the scaffolds, here, tobacco plants were engineered by Israeli company CollPlant to produce human collagen, which was successfully used for 3D bioprinting the vascularized tissue constructs.

This study constitutes an important step towards personalized medicine. Large blood vessels of the exact shape necessary can be printed and implanted together with the tissue that needs to be implanted. This tissue can be formed using the patient’s own cells, eliminating rejection risk.

Dr. Ariel Alejandro Szklanny
Dr. Ariel Alejandro Szklanny

The study received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme.

For the full article in Advanced Materials, click here.

Video demonstrating the research:

New FoodTech Innovation Center

Forty-five years after the family’s first contribution to the Technion – Israel Institute of Technology, and now as part of a multigenerational initiative, the Carasso Family and Carasso Motors are contributing toward a new initiative, promoting cutting-edge food technologies, teaching and R&D in the Faculty of Biotechnology and Food Engineering. The building that until now has housed the Food Industries Center will be renamed the Carasso FoodTech Innovation Center. The donation will be used to renovate the building, as well as expand and upgrade the Center’s research infrastructure. Alongside this activity, a scholarship fund will be established for advanced research.

The gift, which will enhance Israel’s research presence in the global food industry, is part of the family’s legacy – which emphasizes Zionism, excellence in science education, closing gaps in the Israeli society, and investment in infrastructure.

The expanded and upgraded building will be one of its kind in Israel and one of the most advanced in the world; it will feature an R&D center for industrial production, a packaging laboratory, an industrial kitchen, as well as tasting and evaluation units that will be used for teaching and research in the Faculty of Biotechnology and Food Engineering. The Carasso FoodTech Innovation Center will be housed in an existing, dedicated structure alongside the faculty, and will include a visitor area that will expose high-school students to the world of FoodTech, and serve as a hub for startups, where they can benefit from R&D services.

“Eradicating world hunger and improving food security are among the main challenges facing humanity in the 21st century, as defined by the UN’s Sustainable Development Goals,” said Technion President Prof. Uri Sivan. “The Technion has the only faculty in Israel for research in food engineering, a faculty that leads the Israeli FoodTech industry. We are grateful to the Carasso Family for their generous contribution, which will establish the Carasso FoodTech Innovation Center, and will help us promote groundbreaking scientific research in the field, train the next generation of the Israeli FoodTech industry, and maintain the faculty’s position at the global forefront of research and development.”

Yoel Carasso (left), Chairman of Carasso Motors, with Technion President Prof. Uri Sivan

Yoel Carasso, Chairman of Carasso Motors, said: “In 1924, our Grandfather Moshe immigrated with his family to Israel from Thessaloniki, where he was one of the leaders of the Jewish community. In Israel, he cofounded Discount Bank, Ophir Cinema (one of the first movie theaters in Tel Aviv), and of course Carasso Motors Company. For me and for my uncle Shlomo and my cousins – Ioni, Orli, Sarah, Tzipa and Arik – this is coming full circle from a century ago. We chose to support the Carasso FoodTech Innovation Center since the Technion is synonymous with excellence. The Technion is an engine for combining basic and applied science in the Galilee and in Israel as a whole. We believe the Carasso FoodTech Innovation Center will contribute to the industry, and to collaborative work in this field, and thus strengthen the Israeli economy and society. Our family has a history of supporting the Technion, and when the opportunity to establish this center sprang, we knew it was our calling to lead.”

Prof. Marcelle Machluf, Dean of the Faculty of Biotechnology and Food Engineering at the Technion, said “the faculty is one of the only ones in the world that combines the disciplines of bioengineering, technology, food sciences and life sciences. Coping with the COVID-19 pandemic has only emphasized the importance of food and biotechnology in maintaining our existence and meeting future existential challenges. To address the many challenges in this field, including access to healthy, affordable food and innovative medical treatments, we need advanced infrastructure that will enable the integration of new engineering and scientific tools; these will enable us to develop the necessary technologies, as well as the infrastructure and equipment that will support the development and assimilation of the knowledge required to tackle tomorrow’s food challenges. I would like to thank the Carasso Family for their generous contribution, which will allow the faculty to upgrade the infrastructure and equipment needed for the development and integration of the knowledge required to tackle future food challenges.”

Yoel Carasso (left), with Prof. Marcelle Machluf, Dean of the Faculty of Biotechnology and Food Engineering 

Izaac Weitz, CEO of Carasso Motors: “Carasso Motors, with its various brands – Renault, Nissan, Infinity, and Dacia – is committed to innovation and connection with our diverse customer base in Israel. Food technology is an evolving field that brings value in many ways to our stakeholders. Food research tackles environmental and global warming challenges, providing food security and a balanced diet, accelerating paramedical developments that combine medicine and food, and of course contributing to the development of innovative solutions that will put Israel at the forefront of science globally. At Carasso Motors, we jumped at the opportunity to make such a significant contribution to the establishment of this advanced research center, which will also improve and advance Israel’s education and society.”

100 Sunrises a Day

One Hundred Sunrises a Day is a public art exhibition showcasing the work of 12 Israeli artists of Ethiopian descent who deal with social issues through a variety of artistic techniques. The artists originate from the Jewish community of Ethiopians who have made Aliyah over the years. It is currently on display in the new gallery at the entrance to the Ullman Building, on the main campus of the Technion – Israel Institute of Technology in Haifa, and will be open, free of charge, through the end of November 2021.

The exhibition was originally shown in Haifa this past spring, across 100 municipal billboards as part of the “Cultural Touches” program – a series of events produced by the Haifa-Boston Connection. In August 2021, the exhibition opened at the Technion in partnership with Tikva Israelit as a way of bringing art into the public space and making it accessible.

“Israeli Hope” is an initiative of Israel’s President; the program aims to establish partnerships among the four main sectors that comprise Israeli society: secular, religious, ultra-Orthodox, and Arab-Israeli. “100 Sunrises a Day” is part of “Israeli Hope in Academia“, an initiative to increase diversity and representation of different populations, while creating a common space for all of them and preserving each group’s unique identity.

נשיא הטכניון פרופ' אורי סיון בסיור בתערוכה.
Technion President Prof. Uri Sivan taking a tour of the exhibition 

“Promoting multicultural activity on campus and increasing awareness of diversity”

According to Efi Barkai Goral, who heads Tikva Israelit at the Technion, “the program is intended to promote multicultural activity on campus and increase awareness of diversity and cultural competence. The exhibition itself invites us to look at life through the lens of the other. With this in mind, and as part of staff training on cultural competence, meetings are held between artists and faculty members to stimulate thinking and to create dialogue about the place of others within us, as an organization and as individuals.”

Valeria Geselev, curator of the exhibition, said: “In March 2021, my city, Haifa, changed not only because art appeared in spaces dedicated for advertisements. The city changed because it gave room and attention to faces and voices that do not take up space in the public sphere… This is an exhibition that was born on the street, and which expresses the influence of art in the public space. It is not obvious that an academic institution chooses to put on such an exhibition. In doing so, a platform is given to narratives that have not yet been heard.”

Curator Valeria Geselev with two paintings by Haifa-based artist Shimon Wanda: “Lucky” (left) and “Secrets”

Eden Yilma, one of the featured artists, presented her work during a recent Technion tour and spoke of the importance for her of showing art in public spaces, and specifically exhibiting her work at the Technion – a space where academia meets dialogue; she also spoke of the opportunity to interact with the future generation. She presents her compelling story and trajectory as a third-generation Ethiopian in Israel, and her identity search through art.

Story by Deborah Dwek

Producing clean hydrogen fuel from water

Water electrolysis is an easy way to produce hydrogen gas. While hydrogen is considered a clean, renewable fuel, efficient electrolysis requires high electric potential, high pH and in most cases, catalysts based on ruthenium and other expensive metals. Due to the inherent promise of hydrogen, many research groups are striving to develop electrolysis technologies that will make it possible to produce hydrogen fuel at a low electric potential, at a pH between 7-9 and with catalysts based on available and inexpensive metals such as copper, manganese, and cobalt.

Prof. Galia Maayan
Prof. Galia Maayan

Now, Technion researchers have developed a unique system for producing hydrogen from water using little energy and inexpensive materials, as recently reported by The Journal of the American Chemical Society. It is the fastest system of its kind reported so far that operates with available metal (copper) catalysts. The research was led by Professor Galia Maayan, Head of the Biomimetic Chemistry Laboratory at the Schulich Faculty of Chemistry, along with doctoral student Guilin Ruan.

הדוקטורנט גווילין רואן
Doctoral student Guilin Ruan

The researchers designed and developed a homogeneous electrolysis system, or in other words, a system in which the catalyst is soluble in water, so that all components of the system are in the same medium. The innovative and original system is based on (1) copper ions; (2) a peptide-like oligomer (small molecule) that binds the copper and maintains its stability; and (3) a compound called borate whose function is to maintain the pH in a limited range. The main discovery in this study is the unique mechanism that the researchers discovered and demonstrated: the borate compound helps stabilize the metallic center and participates in the process so that it helps catalyze it.

In previous studies, the research group demonstrated the efficacy of using peptide-like oligomers to stabilize metal ions exposed to oxygen – exposure that may oxidize them in the absence of the oligomer and break down the catalyst. Now, the researchers are reporting on the success in creating a very efficient and fast electrolysis system. The stable system oxidizes the water into hydrogen and oxygen under the same desired conditions: low electric potential, pH close to 9 and inexpensive catalysts.

According to Prof. Maayan, the system was inspired by enzymes (biological catalysts) that use the protein’s peptide chain to stabilize the metallic center and by natural energetic processes such as photosynthesis, which are driven by units that use solar energy to transport electrons and protons.

The research was supported by the Israel Science Foundation (ISF) and the Nancy and Stephen Grand Technion Energy Program.

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Not Just COVID: Viruses Spread by Aerosols

SARS-CoV-2, the virus behind today’s global coronavirus pandemic, spreads primarily by inhalation of virus-laden aerosols at both short and long ranges, and a comprehensive new assessment of respiratory viruses finds that many others probably do as well. SARS-CoV, MERS-CoV, influenza, measles, and the rhinoviruses that cause the common cold can all spread via aerosols that can build up in indoor air and linger for hours, an international, interdisciplinary team of researchers has reported in a review published in Science.

Over the last century and at the beginning of this pandemic, it was widely believed that respiratory viruses, including SARS-CoV-2, mainly spread through droplets produced in coughs and sneezes of infected individuals or through touching contaminated surfaces. However, droplet and fomite transmission of SARS-CoV-2 fails to account for the numerous superspreading events observed during the COVID-19 pandemic, or the much higher transmission that occurs indoors versus outdoors.

Airborne transmission is the most likely route, not surface contacts or contact with large droplets

Motivated by a desire to understand the factors leading to the COVID-19 pandemic, researchers from Taiwan, the U.S., and Israel sought to identify as clearly as possible how the coronavirus and other respiratory viruses spread. For example, the team reviewed numerous studies of superspreading events observed during the COVID pandemic, and found the studies consistently showed that airborne transmission is the most likely transmission route, not surface contacts or contact with large droplets. One common factor at these superspreading events was the shared air people inhaled in the same room. Many were linked to crowded locations, exposure durations of one hour or more, poor ventilation, vocalization, and lack of properly worn masks.

The researchers also reviewed evidence collected from many other types of studies — air sampling, polymerase chain reaction (PCR)-based and/or cell culture studies, epidemiological analysis, laboratory and clinical studies, and modeling work — and concluded that airborne transmission is a major, or even dominant transmission pathway for most respiratory diseases, not just COVID-19. “Transmission through inhalation of virus-laden aerosols has been long underappreciated. It is time to revise the conventional paradigms by implementing aerosol precautions to protect the public against this transmission route”, said Chia C. Wang, director of the Aerosol Science Research Center and an aerosol physical chemist at National Sun Yat-sen University, Taiwan, who led the review.

Prevailing paradigms about respiratory disease transmission date back as much as a century, the team noted. Airborne transmission was paternalistically dismissed in the early 1900s by prominent public health figure Charles Chapin due to a concern that mentioning transmission by air would scare people into inaction and displace hygiene practices. An unsupported assumption that erroneously equated infections at close range with droplet transmission has shaped the current paradigm for controlling respiratory virus transmission. However, “this assumption neglects the fact that aerosol transmission also occurs at short distances, because the concentration of exhaled aerosols is higher when one is closer to the infected person emitting them”, said Kim Prather, director of the National Science Foundation Center for Aerosol Impacts on Chemistry of the Environment at UC San Diego’s Scripps Institution of Oceanography at UC San Diego and an aerosol chemist who co-led the review.

Respiratory aerosols are formed by expiratory activities, such as breathing, talking, singing, shouting, coughing, and sneezing. Before COVID-19, the traditional size cut-off between aerosols which float like smoke and droplets which drop had been set at 5 µm, however, 100 µm is a more appropriate size distinction. This updated size better represents the largest particles that can remain suspended in still air for more than five seconds (from a height of 1.5 meters), travel beyond one meter from the infected person, and be inhaled. The physical size predominantly determines how long they can stay suspended in the air, how far they can reach, whether they are inhalable, and how deep they can enter into the respiratory tract if inhaled. “The majority of aerosols produced by respiratory activities are smaller than 5 µm, which allows them to travel deep into the bronchiolar and alveolar regions and deposit there. Studies find that viruses are more enriched in aerosols smaller than 5 µm”, said Prof. Josué Sznitman, an associate professor and head of the Biofluids Laboratory at the Technion’s Faculty of Biomedical Engineering.

Prof. Josué Sznitman

Another distinct behavior of aerosols that should be taken into serious consideration is their capacity to be influenced by airflow and ventilation. Ensuring sufficient ventilation rates, filtration, and avoiding recirculation help reduce airborne transmission of infectious virus-laden aerosols. “Monitoring CO2 with portable meters helps verify that ventilation is sufficient, and implementing portable HEPA (high efficiency particulate air) purifiers and upper room UV disinfection systems also help reduce the concentrations of virus-laden aerosols”, added Jose-Luis Jimenez, an atmospheric aerosol chemist of the University of Colorado Boulder. On the other hand, the plexiglass barriers commonly used to block droplet spray from coughs and sneezes in indoor spaces may “impede proper ventilation and create higher exposures for some people,” said Linsey Marr of Virginia Tech, who has studied airborne transmission of pathogens for years. “They are not recommended except for brief, face-to-face transactions, but even then, masks are better because they help remove aerosols, while barriers just divert them.”

With the surge in infections caused by the Delta variant and the increasing occurrence of “COVID-19 breakthrough cases” (infections among people who have been fully vaccinated), many governments and national disease control agencies have resumed universal masking in public. Universal masking is an effective and economic way to block virus-laden aerosols, reported in the review. However, “we need to consider multiple barriers to transmission such as vaccination, masking, and ventilation. One single strategy is unlikely to be strong enough to eliminate transmission of emerging SARS-CoV-2 variants”, added Seema S. Lakdawala, a virologist of the University of Pittsburgh.

Health benefits extend well beyond the COVID-19 pandemic

As the evidence for airborne transmission of SARS-CoV-2 has increased over time and become particularly strong, agencies have taken notice. In April and May 2021, the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) acknowledged inhalation of virus-laden aerosols as a main route in spreading COVID-19 at both short and long ranges. This means that to mitigate transmission and end this pandemic, decision makers should consider implementing aerosol precautionary measures, including universal masking with attention to mask fit, improving ventilation rates in indoor spaces, avoiding recirculation of contaminated indoor air, installation of air filtration such as HEPA purifiers that can effectively remove airborne particles, and using UV disinfection lamps. “What are traditionally called droplet precautions are not replaced wholesale, but instead are modified, expanded and deployed in a more effective manner in accordance with actual transmission mechanisms,” noted Zeynep Tufekci, a sociologist at the University of Columbia who studies societal challenges in COVID-19 pandemic. Having the correct mental model of transmission of this disease and other respiratory diseases will also allow ordinary people to make better decisions in everyday situations and administrators and officials to create better guidelines and working and socializing environments even after the pandemic, she added.

This pandemic vividly illuminates the importance of the long underestimated airborne transmission route and the necessity of preserving people’s right to breathe clean and pathogen-free air. “What we have learned from this pandemic also lights up the ways for us to make appropriate changes to enter the post-epidemic era,” said Wang. As addressed at the end of this review, these aerosol precautionary measures will not only protect against airborne transmission of respiratory diseases, but also improve indoor air quality and result in health benefits extending well beyond the COVID-19 pandemic.

Read the Science article here.

‘Technion LIVE’ September 2021

Technion – Israel Institute of Technology wishes you a happy and healthy new year, a year to create, develop, research, study, and inspire one another.

To watch our Rosh Hashana video and read about charging electric cars faster, a solution to the oldest conundrums in physics, and other exciting news, check out our September 2021 newsletter, by clicking here.

To read previous issues of Technion LIVE, click here. To subscribe, click here