It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Saturday, January 06, 2024
Pollution-tracking citizen science project offers New York students a breath of fresh air
Fordham University researchers partner with Bronx schools to collect air quality data, highlight impacts of climate change and economic inequality
LEFT: INCIDENCE OF ASTHMA-RELATED EMERGENCY ROOM VISITS BY CHILDREN IN NEW YORK CITY NEIGHBORHOODS, ALONG WITH AIR QUALITY DATA COLLECTED BY A FRESH AIR SITE IN ONE OF THOSE NEIGHBORHOODS. RIGHT: ONE OF THE SENSORS DISTRIBUTED AMONG SCHOOLS AND COMMUNITY CENTERS AS PART OF FRESH AIR.
WASHINGTON, Jan. 4, 2024 – Climate change is one of the biggest issues of the 21st century, a crisis that affects the fate of the entire world as well as our place in it. A warming Earth will destroy ecosystems, flood cities, and lead to countless suffering and death for people worldwide. Part of the challenge of dealing with climate change is helping people understand its complex impacts.
In The Physics Teacher, co-published by AIP Publishing and the American Association of Physics Teachers, researchers from Fordham University partnered with middle and high schools in the Bronx and Manhattan in a citizen science project to collect real-time air quality data. Their project, Fordham Regional Environmental Sensor for Healthy Air (FRESH Air) seeks to improve air quality data while educating the community about the effects of climate change.
The researchers supplied students with commercial air quality sensors along with kits to build their own, which collected indoor and outdoor air pollution measurements at their schools. In the process, those students learned about one of the most immediate effects of climate change.
“We identified asthma, especially childhood asthma, as being a major concern among members of the Bronx community,” said author Stephen Holler. “Respiratory diseases like asthma have a strong connection to air quality, which is negatively impacted by the changing climate. This became the focal point for the project: to educate the Bronx community about climate change through the negative impacts of air quality that are adversely affecting them on a daily basis.”
Thanks to the air quality sensors and the data they produced, students could draw connections between the quality of their air and the health of their planet.
“In June 2023, the students witnessed an orange haze over New York City due to extensive wildfires in eastern Canada, which were a consequence of the warming climate,” said Holler. “This provided a first-hand experience of the connection between the changing climate and the air they breathe.”
The data collected thanks to FRESH Air has revealed more than just impacts from climate change. This study also highlighted disparities between schools in low-income and high-income communities.
“As we partner with the schools and community organizations, we are getting a picture of the asymmetric distribution of pollution,” said Holler. “At some locations, indoor air quality closely tracks outdoor air quality, indicating that some schools are ‘leaky’ and not filtering out particulate matter, exposing students and staff to potential respiratory and cardiovascular disease.”
Ultimately, the researchers at Fordham hope to inspire more students to develop an interest in science.
“The citizen science aspect of the project enables the students and communities to feel they are part of a scientific endeavor and one that has a direct impact on their lives,” said Holler. “Many people do not understand that the scientific process is fundamentally a shared experience. As one of my colleagues is fond of saying, ‘Science is something we do all together.’”
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The article “Project FRESH Air: A community engagement project about health and climate” is authored by Stephen Holler, Usha Sankar, Mark McNeil, Melanie Knuts, and Jahred Jack. It appears in The Physics Teacher on Jan. 4, 2024 (DOI: 10.1119/5.0136945) and can be accessed at https://doi.org/10.1119/5.0136945.
ABOUT THE JOURNAL
Dedicated to the strengthening of the teaching of introductory physics at all levels, The Physics Teacher includes tutorial papers, articles on pedagogy, current research, and news in physics, as well as history, philosophy, and biography. See https://aapt.scitation.org/journal/pte.
ABOUT AAPT
AAPT is an international organization for physics educators, physicists, and industrial scientists with members worldwide. Dedicated to enhancing the understanding and appreciation of physics through teaching, AAPT provides awards, publications, and programs that encourage teaching practical application of physics principles, support continuing professional development, and reward excellence in physics education. AAPT was founded in 1930 and is headquartered in the American Center for Physics in College Park, Maryland.
Air pollution significantly impacts human health, with Hainan Province in China aiming to achieve world-leading ambient air quality by 2035, despite already having relatively good air quality in China. The existing Ambient Air Quality Standards (AAQS) offer insufficient guidance for further enhancing air quality in Hainan, which stands at the forefront of China's environmental protection efforts. Consequently, it is imperative to develop Hainan's local AAQS. This initiative, responding to WHO's strengthened guidelines, aims to address unique regional challenges in air quality assessment, like high background pollutant levels and other complex environmental factors. The development of these tailored standards is crucial for further improving air quality and health outcomes in Hainan and can serve as a model for other regions seeking to surpass national benchmarks and achieve global air quality leadership.
In a landmark study published in Eco-Environment & Health on 28 October 2023, a team from Tsinghua University and several other Chinese institutions presents a comprehensive approach to developing local AAQS tailored for Hainan Province, China. This initiative is part of Hainan's broader effort to enhance its ecological environment and achieve world-class air quality by 2035.
The study began by looking at air quality standards from different countries and regions, focusing on how they measure and limit pollution. For Hainan, the researchers suggested new, realistic goals for reducing common pollutants, considering health effects over both short and long periods. They used these goals, along with local data and international guidelines, to create Hainan's own standards.
To predict if Hainan can meet these goals, the researchers used a computer program called the Community Multiscale Air Quality (CMAQ) model. This program helped them see how the air quality might change by 2035 with different ways of controlling pollution. They found that with strong policies, Hainan could indeed meet these new, stricter air quality goals by 2035.
Lead researcher Bin Zhao from Tsinghua University emphasizes, "Developing local AAQS is critical for regions like Hainan, where the standard needs to reflect local conditions while aiming for global leadership in air quality. Our research is a step towards achieving that delicate balance."
The pioneering work of establishing local AAQS in Hainan Province represents a significant step towards a healthier environment and serves as a model for regions worldwide. As the province moves towards implementing these standards, it embarks on a path to achieving world-leading air quality by 2035.
The study estimates that adhering to the new standards could prevent thousands of premature deaths annually by 2035 due to reduced long-term exposure to PM2.5 and O3. This proactive approach not only promises a healthier future for Hainan's residents but also sets a precedent for other regions to develop their own localized air quality standards.
The National Key R&D Program of China (2022YFC3700702); The Energy Foundation, and the Tsinghua-Toyota Joint Research Institute Inter-disciplinary Program.
Eco-Environment & Health (EEH) is an international and multidisciplinary peer-reviewed journal designed for publications on the frontiers of the ecology, environment and health as well as their related disciplines. EEH focuses on the concept of "One Health" to promote green and sustainable development, dealing with the interactions among ecology, environment and health, and the underlying mechanisms and interventions. Our mission is to be one of the most important flagship journals in the field of environmental health.
The pathogenic potential of inhaling the inert fibrous nanomaterials used in thermal insulation (such as asbestos or fibreglass) is actually connected not to their chemical composition, but instead to their geometrical characteristics and size. This was revealed by a study, published on 3 January 2024 in the journal Nature Nanotechnology, conducted on glass nanofibers by a French-Chinese team including a CNRS chemist.1
The reason for this is the inability of the macrophages2 naturally present in pulmonary alveolar tissue to eliminate foreign bodies that are too large. The study was initially conducted in vitro with electrochemical nanosensors, and revealed that when confronted with inert nanofibers over 15 microns in length,3 the cells are unable to distend enough to entirely encapsulate them within their “digestive” vesicle. This results in leaked secretions that are very harmful for the alveolar walls, which this study detected, characterised, and quantified for the first time.4 An experiment on rats subsequently showed that regular unprotected inhalation of similar inert fibrous nanometerials, whatever they may be, causes repeated pulmonary lesions that can eventually lead to the development of fibroma.
This discovery poses a challenge for the use of inert nanofibre felts in construction, which had heretofore been deemed to be less harmful than the asbestos it replaced, but that in reality could present the same health risks for those handling it.
Notes :
1 From the Selective Activation Processes via Uni-Electronic or Radiative Energy Transfer Laboratory (CNRS/ École normale supérieure – PSL/Sorbonne Université), in collaboration with Wuhan University.
2“Big eater” cells belonging to groups of white blood cells whose primary role is to eliminate cell debris and pathogenic biological agents throughout the body.
3 Or 0.015mm, a micron measuring 10-3 mm.
4 The ROS and RNS species (species reactive to oxygen and nitrogen) secreted by macrophages are known for attacking the bioorganic components of healthy cells, and cause inflammation and mutations that are often cancerous. While the phenomenon of “frustrated phagocytosis” had already been observed, its role in the pathogenesis of the concerned diseases had not yet been clearly established.
Transmission electron microscopy (TEM) image
tip of an electrochemical nanosensor positioned at the invagination of the phagocytal sac of a RAW 264.7 mouse macrophage after 12 h of inhibited phagocytosis; scale bar, 10 μm.
As concerns over the world’s declining bird population mount, animal ecologists developed an analytical approach to better understand one of the latest threats to feathered creatures: the rise of wind and solar energy facilities.
“Bird mortality has become an unintended consequence of renewable energy development,” said Hannah Vander Zanden, an assistant professor of biology at the University of Florida. “If we want to minimize or even offset these fatalities, especially for vulnerable populations, we need to identify the geographic origin of affected birds. In other words, are the dead birds local or are they coming from other parts of North America?”
Birds can be killed when they collide with wind turbines, fly into solar panels they mistake for bodies of water or become singed by the intense heat from concentrating solar power plants. While the death rate of birds due to these energy facilities is far less than deaths due to domestic cats and collisions with building, efforts to mitigate this problem is important, scientists say.
Vander Zanden and colleagues performed geospatial analyses of stable hydrogen isotope data obtained from feathers of 871 individual birds found dead at solar and wind energy facilities in California, representing 24 species.
Their analysis of natural-occurring markers in the feathers provided information about where the feathers were grown based on the water the birds consumed.
“With these markers, we could determine whether the bird was local or if it was migrating from somewhere else,” said Vander Zanden, who is the principal investigator of UF’s Animal Migration and Ecology Lab.
Results from the study, which were published Friday in the journal Conservation Biology, show that the birds killed at the facilities were from a broad area across the continent. Their geographical origins varied among species and included a mix of local and nonlocal birds.
Researchers found most birds killed at solar facilities were nonlocal and peaked during the migratory periods of April and September through October. The percentage of migratory birds found at wind facilities nearly matched that of local birds, at 51%, Vander Zanden said.
“This kind of data can help inform us about best strategies to use to minimize or mitigate the fatalities,” she said. “For example, facilities management could work with conservationists to improve the local habitat to help protect local birds or improve other parts of the species’ range where the migratory birds originate.”
The results also illustrate the power of stable isotope data to assess future population growth or decline patterns for birds due to a variety of reasons.
“Studying the remains of animals is a noninvasive approach to get information that is otherwise hard to track and apply to conservation,” Vander Zanden said. “It’s a great way to understand the mysteries about animals.”
THE UPPER PANEL DEPICTS THE COASTAL FOREST PRE-TSUNAMI, WHILE THE LOWER PANEL ILLUSTRATES THE FOREST POST-TSUNAMI. EACH COLUMN REPRESENTS THE PERCENTAGE DECREASE IN COASTAL TREE COVER RESULTING FROM THE TSUNAMI EVENT (1: NO CHANGE, 5: 41-50%, 10: 91-100%). IN CASES WHERE THERE WAS A 91-100% DECREASE IN TREE COVER, INDICATED BY THE INSET WITH THE BLACK FRAME IN THE BOTTOM RIGHT IMAGE, NEARLY ALL TREES WERE TOPPLED BY THE TSUNAMI. IT IS IMPORTANT TO NOTE THAT WE MAGNIFIED THE SATELLITE IMAGES/AERIAL PHOTOGRAPHS TO ASSESS THE PERCENTAGE DECREASE IN COASTAL FOREST COVER ATTRIBUTABLE TO THE TSUNAMI EVENT.
Coastal forests in Japan had predominantly been afforested with black pine (Pinus thunbergii), a shade-tolerant tree species that can withstand dry land ecosystems and harsh coastal environments. This afforestation initiative, dating back to the Edo period (1603~1867), aimed to mitigate the deleterious effects of robust winds and sand blowing. Subsequent to the Great East Japan Earthquake in 2011, interest shifted to the potential protective effects of coastal forests in reducing the destructive power of tsunamis.
The Great East Japan Earthquake tsunami damaged a total of 2,800 hectares (ha; 10,000 square meters) of coastal forest. While the damage was immense, the devastation provided an opportunity to study which coastal forests withstood the tsunami impact and why some forests fared better than others. The forests can only mitigate tsunami effects if trees remain intact during the tsunami. Recently, scientists from Yokohama National University discovered that coastal forests that contained mixed tree species bore the tsunami forces better and with less damage than monoculture forests made up exclusively of black pine.
“Prior studies have established that coastal forests decrease the hydrodynamic forces exerted by tsunami on structures and alter inland debris dispersion based on the density and size structure of trees. However, limited attention has been devoted to exploring the role of species diversity in coastal forests. We revealed that mixed coastal forests with black pine exhibited a diminished vulnerability to tsunami impacts when contrasted with monoculture forests,” said Yuki Iwachido, first author of the study paper and assistant professor at Yokohama National University.
The research team determined the effects of species diversity in coastal forests by analyzing satellite images and aerial photographs of coastal forests before and after the Great East Japan Earthquake tsunami on 11 March 2011. The degree of damage between forests that contained only black pine trees was compared to the damage experienced in mixed species forests made up of black pine and other broad-leaved trees.
The researchers hypothesize that mixed forests are less susceptible to tsunami damage because the root morphologies of different tree species utilize more soil space and resources than a single species of tree. In theory, this could enhance aboveground tree growth and overall stability of the mixed species forests. One limitation of the research was that the scientists couldn’t compare their results to a monoculture of broad-leaved trees and therefore could not remove the impact of coniferous trees.
The study also found a benefit in complex tree planting arrangements compared to simple arrangements. Analysis of the visual impact of the Great East Japan Earthquake tsunami suggests that forests with complex spatial structures were more able to withstand tsunami forces.
The research team acknowledges that more studies are required to better understand the capacity of coastal forest tsunami protection and how to maximize its safeguarding effect. “This study primarily focused on analyzing only damage patterns to coastal forests caused by tsunami impacts utilizing satellite images. There is a pressing need to elucidate the mechanisms by which mixed coastal forests alleviate the impacts of tsunamis,” said Takehiro Sasaki, senior author of the study paper and the professor at Yokohama National University.
Minori Kaneko from the Graduate School of Environment and Information Sciences at Yokohama National University in Yokohama, Japan also contributed to the research study.
This work was financially supported by a Fostering Joint International Research A grant (no. 19KK0393) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
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Yokohama National University (YNU or Yokokoku) is a Japanese national university founded in 1949. YNU provides students with a practical education utilizing the wide expertise of its faculty and facilitates engagement with the global community. YNU’s strength in the academic research of practical application sciences leads to high-impact publications and contributes to international scientific research and the global society. For more information, please see: https://www.ynu.ac.jp/english/
Compounds that obstruct the "landing gear" of a range of harmful viruses can successfully protect against infection by the virus that causes COVID-19, a study published today and led by Dana-Farber Cancer Institute scientists shows. Based on the findings, researchers have launched a human clinical trial of one such compound made by chemically stabilizing a key coronavirus peptide.
If the compound, called a stapled lipopeptide, proves effective as a nasal spray in the trial, it could be the basis for a new drug modality to prevent or treat COVID-19, say the authors of the study, posted online today in the journal Nature Communications. Because such compounds foil a mechanism used by many types of viruses to enter and infect cells, stapled lipopeptides may also be effective against dangerous and potentially deadly viruses such as RSV, Ebola, and Nipah, as the authors also demonstrate in their study.
"Although vaccines, monoclonal antibodies, and small molecule drugs have played a crucial role in protecting people from life-threatening COVID-19 infection, there remains a critical gap in the treatment arsenal," says Loren Walensky, MD, PhD, Physician and Principal Investigator, Linde Program in Cancer Chemical Biology at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. He led the research with Gregory Bird, PhD, of Dana-Farber and Robert Davey, PhD, of Boston University’s National Emerging Infectious Diseases Laboratories (NEIDL).
“The constant evolution of the virus and the emergence of new variants has markedly decreased the effectiveness of immune-based approaches, requiring periodic reformulation of vaccines. What has been missing are fast-acting, easy-to-administer, and resistance-proof agents that can be used before or after exposure to the virus to directly prevent infection or reduce symptoms. Our study is an encouraging indication that stapled lipopeptides offer that potential,” Walensky added.
Unlike mRNA vaccines, which are a form of immune-based therapy that provides delayed protection and also requires periodic administration due to viral mutation and/or waning immunity, the stapled lipopeptides developed by Walensky's lab act directly on SARS-CoV-2, the coronavirus responsible for COVID-19, interfering with its ability to infect healthy cells. Because this approach does not use the immune system as an intermediary, it is especially promising for people with weakened immune systems, either due to their disease or treatment with immunosuppressive agents, such as chemotherapy.
Walensky's lab has pioneered the development and application of stapled peptides for nearly 20 years. These unique agents consist of natural peptides – a stretch of amino acids in a defined sequence – whose bioactive structure is chemically stabilized by an installed “staple” and, in this case, further linked to a lipid, which is believed to help concentrate the stapled peptide at the site of viral infection – the membrane surface of the otherwise healthy cell. The new study shows that stapled lipopeptides are exceptionally stable, resisting extremes of temperature and chemical conditions, an important feature for persistence both inside and outside the body. The design strategy not only prevents peptide degradation in the body upon administration, but also remedies prior challenges with shipment and storage, such as the required cold chain for COVID-19 vaccines.
In 2010, Walensky's lab first developed double-stapled peptides that target the same key step in the process by which the human immunodeficiency virus (HIV) binds to, and then infects, human cells, causing AIDS. The stapled peptides mimicked the virus's "landing gear," a bundle of six coils or “helices” of the virus that comes together, enabling the virus to fuse with the membrane of the host cell. The therapeutic approach, known as fusion inhibition, prevents the virus from entering the cell to off-load its nucleic acid blueprint, which otherwise turns the cell into a virus-producing factory. The stapled peptide, which mimics one of the coiled regions, disrupts formation of the fusion apparatus, halting infection at its source.
In 2014, Walensky's team developed analogous stapled peptides targeting this same feature of the RSV virus, which can cause severe respiratory illness and even respiratory failure in the elderly and very young alike. They showed that administering the stapled peptide as a nose drop could prevent RSV infection in mice and also prevent the spread of established nasal infection from migrating to the lungs. When the COVID-19 pandemic broke out in early 2020, Walensky's lab promptly converted one of the coiled motifs of the SARS-CoV-2 six-helix bundle into a stapled peptide in an effort to develop a therapeutic for pre- and post-exposure prophylaxis.
"Remarkably, the viral peptide sequence that we use to block the fusion apparatus is 100% identical between SARS-CoV-2 and SARS1, which emerged as a deadly respiratory virus in 2003,” notes Walensky. He points out that, in contrast to the viral sequences that mutate frequently to evade immune-based therapies, the virus’s fusion sequences are rarely altered due to the critical role of six-helix bundle assembly in promoting viral infection. In cooperation with researchers expert in highly pathogenic viruses at the NEIDL, Walensky's team began developing dozens of stapled peptide fusion inhibitors for anti-viral testing, altering the location of the staple and the linker between the staple and the lipid, to determine which version worked best against the broadest spectrum of SARS-CoV-2 variants. Ironically, as the virus evolved to evade vaccines and monoclonal antibodies, the more effective the stapled lipopeptides became, owing to the essential nature of the fusion mechanism they target.
Then, in partnership with the laboratory of Richard Bowen, DVM, PhD, of Colorado State University and the newly formed Red Queen Therapeutics of Cambridge, Massachusetts that licensed the Dana-Farber technology, the Walensky lab began testing the inhibitors in hamsters. The studies evaluated a lead stapled lipopeptide as a preventive and therapeutic agent. The animals were randomly selected to receive an inhibitor before and/or after nasal inoculation with SARS-CoV-2.
The results were very encouraging, Walensky remarks. The animals in each group that received the inhibitor maintained their weight, an indication that they remained well despite viral exposure. Examination of their noses showed a relative drop in viral titers compared to the untreated control group and evaluation of their lung tissue found that the animals were significantly protected from severe pneumonia, a common complication of COVID-19.
"Similar to what we saw with RSV, nasal treatment with a stapled peptide fusion inhibitor – even if given after inoculation with SARS-CoV-2 – prevented the infection from adversely affecting the lungs and causing severe disease," Walensky comments.
A second set of studies explored whether the inhibitors could help reduce transmission of the virus from one hamster to another. Again, the results were encouraging. "Animals that weren't treated consistently lost weight. Those that received treatment, either before or after exposure to an infected hamster, preserved their weight," Walensky notes. Correspondingly, viral loads in the noses and lungs of treated animals were lower than in untreated animals.
The fact that many viruses with pandemic potential rely on the six-helix bundle to enter and infect cells suggests that stapled lipopeptides developed by Walensky's lab can be adapted to block or reduce infection by other viruses “on demand.”
“Red Queen Therapeutics was founded on the conviction that this novel technology from the Walensky lab would be broadly applicable in successfully combating viral threats, using a pre- and post-exposure prophylaxis paradigm, and COVID presents a proving ground as well as an important opportunity in its own right,” said Ron Moss, M.D., CEO of Red Queen Therapeutics. “We are excited to validate data in this publication with our human trials in SARS-CoV-2 now under way and anticipate having data to share later this quarter,” he added.
"This approach has the potential to fill an important gap in our arsenal against COVID-19 and other viruses that cause severe respiratory and hemorrhagic diseases," Walensky relates. "Imagine being able to protect yourself from COVID-19 or other disruptive respiratory viruses with a simple nasal spray that you could use to avoid infection at a large gathering or after exposure to a close contact who turns out to test positive for SARS-CoV-2. That is the promise this work holds, not only for otherwise healthy individuals, but especially for immunocompromised patients who remain most at risk of severe infection. As a Dana-Farber chemical biology lab that specializes in studying mechanisms of cancer chemoresistance in children, my group has also been interested in tackling the secondary causes of morbidity and mortality in our patients, and that includes life-threatening infections by treatment-resistant bacteria and viruses.
The research was supported by the Dana-Farber Cancer Institute, a grant from the Massachusetts Consortium on Pathogen Readiness and the National Institutes of Health to the NEIDL, and the Pre-clinical Services Program of the National Institute for Allergy and Infectious Diseases, which funded in part the animal testing performed at Colorado State University.
JOURNAL
Nature Communications
METHOD OF RESEARCH
Experimental study
ARTICLE PUBLICATION DATE
4-Jan-2024
UofL study shows nicotine in e-cigarettes may not be harmless, as some claim
Pod-based e-cigarettes with higher nicotine more likely to cause irregular heartbeat
With the start of a new year, smokers and vapers may have resolved to quit or cut back on the habit to improve their health. They may want to use caution, however, if their strategy involves switching from cigarettes to e-cigarettes, considered by some to be a less harmful alternative.
A new study from the University of Louisville shows the nicotine in certain types of e-cigarettes may be more harmful than others, increasing risk for irregular heartbeat, or heart arrhythmias.
A popular claim is that nicotine in e-cigarettes is relatively harmless, whereas additives and combustion products largely account for the harms of traditional cigarettes. The UofL research, which tested the effects of e-cigarettes with various types and doses of nicotine in animal models, showed that the nicotine form contained in pod-based e-cigarettes, nicotine salts, led to heart arrhythmias, particularly at higher doses.
In the study, published in Nicotine and Tobacco Research, researchers compared heart rate and heart rate variability in mice exposed to vape aerosols containing different types of nicotine. The aerosols contained either freebase nicotine, used in older types of e-cigarettes; nicotine salts, used in Juul and other pod-based e-cigarettes; or racemic freebase nicotine, simulating the recently popularized synthetic nicotine; and their effects were compared to nicotine-free e-cigarette aerosols or air. In addition, the research team delivered increasing concentrations of the nicotine over time, from 1% to 2.5% to 5%.
The nicotine salts induced cardiac arrhythmias more potently than freebase nicotine, and the cardiac arrhythmias increased with the higher concentrations of nicotine.
“This suggests the nicotine is harmful to the heart and counters popular claims that the nicotine itself is harmless,” said Alex Carll, assistant professor in UofL’s Department of Physiology, who led the study. “Our findings provide new evidence that nicotine type and concentration modify the adverse cardiovascular effects of e-cigarette aerosols, which may have important regulatory implications.”
The study also revealed that the higher levels of nicotine salts increased sympathetic nervous system activity, also known as the fight-or-flight response, by stimulating the same receptor that is inhibited by beta blockers, heart medications which are prescribed to treat cardiac arrhythmias. In the autonomic nervous system, sympathetic dominance increases the fight-or-flight response in bodily functions, including heart rate.
“The nicotine in e-cigarettes causes irregular heartbeats (arrhythmias) in a dose-dependent manner by stimulating the very receptor that many heart medications are designed to inhibit,” Carll said.
The findings conclude that inhalation of e-cig aerosols from nicotine-salt-containing e-liquids could increase cardiovascular risks by inducing sympathetic dominance and cardiac arrhythmias.
This work is part of a growing body of research on the potential toxicity and health impacts of e-cigarettes reported by the American Heart Association Tobacco Regulation and Addiction Center, for which UofL serves as the flagship institute. The team’s previous research found that exposure to e-cigarette aerosols containing certain flavors or solvent vehicles caused ventricular arrhythmias and other conduction irregularities in the heart, even without nicotine, leading Carll to speculate that the arrhythmias may not be the result of the nicotine alone, but also by the flavors and solvents included in the e-cigarettes.
The researchers concluded that, if these results are confirmed in humans, regulating nicotine salts through minimum pH standards or limits on acid additives in e-liquids may mitigate the public health risks of vaping.
Even without regulatory changes, however, the research suggests that users may reduce potential harm by opting for e-cigarettes with freebase nicotine instead of nicotine salts or using e-cigarettes with a lower nicotine content.
