Long-term stroke death rates are higher among Black Medicare patients

American Stroke Association International Stroke Conference -- presentation P655

AMERICAN HEART ASSOCIATION

Research News

 

DALLAS, March 11, 2021 — A long-term look at Medicare patients shows that Black patients who have an ischemic stroke (blocked blood flow to the brain) die at a higher rate than white patients, even after accounting for preexisting health conditions, according to preliminary research to be presented at the American Stroke Association’s International Stroke Conference 2021. The virtual meeting is March 17-19, 2021 and is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

“So much of what we know is limited to the early or acute phase — the first two weeks after a stroke,” said lead study author Judith H. Lichtman, Ph.D., M.P.H., professor and chair of the department of epidemiology at the Yale School of Public Health in New Haven, Connecticut. “When you have a stroke, it’s not just about the acute event, it’s about the early recovery period to secondary prevention visits that affect your long-term chances of survival.”

Researchers analyzed data on 744,044 Medicare beneficiaries (ages 65 and older) who had been treated at U.S. hospitals for ischemic stroke between 2005 and 2007. Overall, 85.6% were white, 9.9% were Black and 4.5% were of other races or ethnic groups. Black patients had higher rates of kidney failure, dementia and diabetes. Atherosclerosis and chronic obstructive pulmonary disease (COPD) were more common in white patients.

Patients were followed over a 10-year period, and analysis of the data found:

• Overall, the death rate was about 75%. Black patients had the highest death rate at 76.4%, followed by whites at 75.4%; and the death rate for those of other races or other ethnic groups was 70.3%.
• Even after adjusting for differences in preexisting health problems, the risk of death within 10 years after stroke was about 4% higher for Black patients than white patients. However, the stroke death risk was about 8% lower for those of other races.
• Importantly, within the first year after hospital discharge for ischemic stroke, the death rate for Black patients started to climb slightly in comparison to whites and other races, and these differences continued over the decade.

“These are racial differences in long-term stroke survivorship, and these differences start within the first year after a stroke,” Lichtman said. “We need to take a closer look at the recovery period and think about how we can optimize secondary prevention and post-stroke care for everybody. Stroke care during the first year after a stroke plays an important role in the long run.”

Future research will need to investigate the reasons behind these differences in death rates among Black patients and white patients. “Currently, much of the focus is on the acute stroke event, itself, yet we need to find out more – are there racial differences using rehab services, are some people not seeing neurologists and getting follow up care?” Lichtman said. “Stroke is an acute event, but it’s just as important to focus on early follow-up care that will support patients for better long-term outcomes and survival.”

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Co-authors are Erica C. Leifheit, Ph.D.; Yun Wang, Ph.D.; Andrew Arakaki, M.P.H.; and Larry B. Goldstein, M.D. The authors’ disclosures are available in the abstract.

The study was funded by the American Heart Association and the National Institute on Aging of the National Institutes of Health.

Additional Resources:

• Multimedia is available on the right column of release link https://newsroom.heart.org/news/long-term-stroke-death-rates-are-higher-among-black-medicare-patients?preview=61bb19ecbb6986bc5d17491112fb0285
• What is Brain Health?
• Stroke risk factors
• More stroke awareness, better eating habits may help reduce stroke risk for young adult African Americans
• Risk of stroke may more than double for African Americans who smoke
• African Americans live shorter lives due to heart disease and stroke
• For more news at ASA International Stroke Conference 2021, follow us on Twitter @HeartNews #ISC21.

Statements and conclusions of studies that are presented at the American Heart Association’s scientific meetings are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers are available here, and the Association’s overall financial information is available here.

The American Stroke Association’s International Stroke Conference (ISC) is the world’s premier meeting dedicated to the science and treatment of cerebrovascular disease. ISC 2021 will be held virtually, March 17-19, 2021. The 3-day conference will feature more than 1,200 compelling presentations in 21 categories that emphasize basic, clinical and translational sciences as they evolve toward a better understanding of stroke pathophysiology with the goal of developing more effective therapies. Engage in the International Stroke Conference on social media via #ISC21.

About the American Stroke Association

The American Stroke Association is devoted to saving people from stroke — the No. 2 cause of death in the world and a leading cause of serious disability. We team with millions of volunteers to fund innovative research, fight for stronger public health policies and provide lifesaving tools and information to prevent and treat stroke. The Dallas-based association officially launched in 1998 as a division of the American Heart Association. To learn more or to get involved, call 1-888-4STROKE or visit stroke.org. Follow us on Facebook, Twitter.

Black and Hispanic workers overrepresented in occupations with higher risk for COVID-19 exposure

Black workers are especially overrepresented in indoor jobs that require close proximity to others, while Hispanic workers are especially overrepresented in high proximity outdoor jobs, researchers report in the American Journal of Preventive Medicine

ELSEVIER

Research News 

Ann Arbor, March 11, 2020 - Black and Hispanic people experience a higher risk for COVID-19 and severe illness, influenced by factors such as discrimination, housing, and healthcare access and utilization. Now, a new study in the American Journal of Preventive Medicine, published by Elsevier, identifies specific job categories that put workers at risk because they require working in close contact with others. Some of these jobs have a disproportionately high number of Black or Hispanic workers. The findings should be used to inform workplace interventions to reduce the risk for these particularly vulnerable communities.

"About three-quarters of US workers have jobs either indoors or outdoors that involve contact with other people that is sufficiently close to put them at higher risk for COVID-19," explained co-investigators Jean M. Cox-Ganser, PhD, and Paul K. Henneberger, ScD, both of the Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA. "Our findings provide insight on where to reach the greatest number of workers who are potentially at risk for COVID-19 based on working close to others, including which occupations have larger numbers of minority workers."

Researchers used data from the Occupational Information Network (O*NET) and the Bureau of Labor Statistics (BLS) to classify the occupations of all US workers into six categories for risk of COVID-19 exposure at work: low, medium, or high proximity work indoors; and low, medium, or high proximity work outdoors. They studied the distribution of workers by occupation in the higher risk categories (medium or high proximity indoors and high proximity outdoors) and determined where Black and Hispanic workers were overrepresented.

Information on 772 detailed occupations and 144,525,054 workers was examined. Researchers found that a high proportion of US workers may be at greater risk for exposure to COVID-19 because their occupations involve either high proximity to others indoors or outdoors (25.2 percent, 36.5 million people) or medium proximity work indoors (48.0 percent, 69.6 million workers). A higher proportion of Black workers perform high proximity indoor work compared to all workers (27.5 percent vs 22.1 percent). In contrast, Hispanic workers had higher representation in outdoor work categories: 5.0 percent Hispanic vs 3.1 percent all workers in high proximity outdoor work and 7.0 percent vs 5.3 percent in medium proximity outdoor work.

Black workers were overrepresented in 103 of the 772 occupations. Eighty of those occupations were in the proximity and indoor/outdoor categories at higher risk for exposure and included 34.7 percent of all Black workers. Hispanic workers were overrepresented in 124 of the 772 occupations. Seventy-six of these occupations were in higher risk categories and included 21.5 percent of all Hispanic workers.

The authors highlighted the most populous occupations in each of the three higher risk exposure categories where Black or Hispanic workers were overrepresented. The indoor high proximity occupations for Black workers were Home Health Aides, Nursing Assistants, and Personal Care Aides, while for Hispanic workers they were Restaurant Cooks, Medical Assistants, and Dining Room/Cafeteria Attendants and Bartender Helpers. The outdoor high proximity occupations had many fewer Black than Hispanic workers. In this category large numbers of Hispanic workers were Landscaping and Groundskeeping Workers, Carpenters, and Cement Masons and Concrete Finishers. Looking at indoor medium proximity work, Laborers and Freight, Stock and Material Movers included large numbers of both Black and Hispanic workers. Additionally, large numbers of Black workers were Cashiers and Stock Clerks/Order Fillers, while large numbers of Hispanic workers were Hand Packers/Packagers and Food Preparation workers.

Prevention strategies should consider worksite conditions, and communication messages should be tailored to the languages and preferred media of the workforce.

Although there are recommendations for keeping a distance of at least six feet between people to minimize the spread of SARS-CoV-2, such social distancing may not be possible in indoor and outdoor occupations that require high physical proximity to perform work tasks.

"Efforts to control the spread of the virus that causes COVID-19 are still needed in all aspects of our lives, including at work. Becoming complacent in wearing a mask, physical distancing, and other prevention efforts during the rollout of the vaccine could have unfortunate consequences not only for ourselves, but also for our family members, co-workers, and friends," cautioned Dr. Cox-Ganser and Dr. Henneberger.

"We all have a role to play, including getting the COVID-19 vaccine when it is offered."

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Experiences of Latinx Individuals Hospitalized for COVID-19

A Qualitative Study

Lilia Cervantes, MD^1,2,3; Marlene Martin, MD⁴; Maria G. Frank, MD^1,3; et alJulia F. Farfan, BS⁵; Mark Kearns, MD^1,3; Luis A. Rubio, MD⁴; Allison Tong, PhD^6,7; Andrea Matus Gonzalez, BNutrSc^6,7; Claudia Camacho, BS¹; Adriana Collings, MPH²; William Mundo, MPH³; Neil R. Powe, MD⁴; Alicia Fernandez, MD⁴

Author Affiliations Article Information

JAMA Netw Open. 2021;4(3):e210684. doi:10.1001/jamanetworkopen.2021.0684

 March 11, 2021

editorial comment icon 

Editorial

Comment

Key Points

Question  Can experiences of Latinx adults hospitalized with coronavirus disease 2019 (COVID-19) inform improvements to public health and health care?

Findings  In this qualitative study of 60 Latinx adults, participants reported COVID-19 misinformation, felt COVID-19 compounded existing social disadvantage, and risked infection because of the need to work. Participants hesitated to seek hospital care because of immigration and economic concerns.

Meaning  These findings suggest that to contain community spread and reduce unnecessary morbidity, immigration, employment, and economic distress must be addressed through tailored public health messaging and public policy interventions that improve economic conditions.

Abstract

Importance  Latinx individuals, particularly immigrants, are at higher risk than non-Latinx White individuals of contracting and dying from coronavirus disease 2019 (COVID-19). Little is known about Latinx experiences with COVID-19 infection and treatment.

Objective  To describe the experiences of Latinx individuals who were hospitalized with and survived COVID-19.

Design, Setting, and Participants  The qualitative study used semistructured phone interviews of 60 Latinx adults who survived a COVID-19 hospitalization in public hospitals in San Francisco, California, and Denver, Colorado, from March 2020 to July 2020. Transcripts were analyzed using qualitative thematic analysis. Data analysis was conducted from May 2020 to September 2020.

Main Outcomes and Measures  Themes and subthemes that reflected patient experiences.

Results  Sixty people (24 women and 36 men; mean [SD] age, 48 [12] years) participated. All lived in low-income areas, 47 participants (78%) had more than 4 people in the home, and most (44 participants [73%]) were essential workers. Four participants (9%) could work from home, 12 (20%) had paid sick leave, and 21 (35%) lost their job because of COVID-19. We identified 5 themes (and subthemes) with public health and clinical care implications: COVID-19 was a distant and secondary threat (invincibility, misinformation and disbelief, ingrained social norms); COVID-19 was a compounder of disadvantage (fear of unemployment and eviction, lack of safeguards for undocumented immigrants, inability to protect self from COVID-19, and high-density housing); reluctance to seek medical care (worry about health care costs, concerned about ability to access care if uninsured or undocumented, undocumented immigrants fear deportation); health care system interactions (social isolation and change in hospital procedures, appreciation for clinicians and language access, and discharge with insufficient resources or clinical information); and faith and community resiliency (spirituality, Latinx COVID-19 advocates).

Conclusions and Relevance  In interviews, Latinx patients with COVID-19 who survived hospitalization described initial disease misinformation and economic and immigration fears as having driven exposure and delays in presentation. To confront COVID-19 as a compounder of social disadvantage, public health authorities should mitigate COVID-19–related misinformation, immigration fears, and challenges to health care access, as well as create policies that provide work protection and address economic disadvantages.

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Experiences of Latinx Individuals Hospitalized for COVID-19: A Qualitative Study | Research, Methods, Statistics | JAMA Network Open | JAMA Network

Differences found in stroke severity and post-stroke care among Black and Hispanic women

American Stroke Association International Stroke Conference - Presentation 51

AMERICAN HEART ASSOCIATION

Research News

 

DALLAS, March 11, 2021 -- Black and Hispanic women ages 65-74 years old hospitalized with stroke had more severe strokes than their white counterparts, according to preliminary research to be presented at the American Stroke Association International Stroke Conference 2021. The virtual meeting is March 17-19, 2021 and is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

According to the American Heart Association, Black women have a higher rate of stroke (3.8%) when compared to white women (2.5%) of similar age, which could lead to a higher death rate or worse quality of life.

"The Black and Hispanic female stroke survivors 65-84 years old were younger and had a greater chance of being sent to a skilled nursing or rehabilitation center when compared to older white females who were discharged home after their stroke," said study author Trudy R. Gaillard, Ph.D., R.N., an associate professor at Florida International University's College of Nursing and Health Sciences in Miami, Florida.

Researchers analyzed Get With The Guidelines® Stroke health information in 1,587 female patients who were discharged after a stroke from Baptist Hospital of Miami from April 2014 to March 2019. The female stroke patients were categorized by age group: 65-74 years old (young), 75-84 years old (middle) and 85 years or older (older). The data analyzed included stroke type and severity; other health issues; age; race/ethnicity; and discharge information - whether patients were discharged home, to a skilled nursing center or to a rehabilitation facility. Black women with stroke accounted for about 27% of all patients; while 37.5% were Hispanic and about 35% were white. Among the participants ages 85 years or older hospitalized for stroke, 18.4% were Black women, 36% were Hispanic women and about 40% were white women.

Researchers found:

• Black and Hispanic women ages 65-74 years old hospitalized with stroke had more severe strokes than white women of the same age group. Nearly 99% of the women had health insurance, although Black women were the most likely to be without health insurance. After controlling for age, race, and stroke severity, Black and Hispanic women in the younger (65-74 years) and middle age (75-84 years) groups had a greater chance of being sent to a skilled nursing or rehabilitation center when compared to white women in the oldest age group (85 years and older).

"Future studies are needed to explore the type of health care facilities that women are discharged to after stroke and to examine the quality of care received," Gaillard said. "This type of study should be done in multiple cities, across care settings, including inpatient rehabilitation facilities, skilled nursing facilities or home with or without home health and outpatient rehabilitation services."

Limitations of the study include that it was done in only one hospital and the researchers did not examine patients' outcomes after discharge.

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Co-authors are Joan Vaccaro, Ph.D.; Amy K. Starosciak, Ph.D.; Starlie Belnap, Ph.D.; and Felipe De Los Rios La Rosa, M.D., FAHA. Author disclosures are in the abstract.

The Nicole Wertheim Innovation Opportunity Endowment Fund of the Nicole Wertheim College of Nursing and Health Science at Florida International University funded this study.

Additional Resources:

Multimedia is available on the right column of release link https://newsroom.heart.org/news/differences-found-in-stroke-severity-and-post-stroke-care-among-black-and-hispanic-women?preview=a487f17d6a8df78d87bbb89cc52490f0

What is brain health?
Women's lifestyle changes, even in middle age, may reduce future stroke risk
Blacks, Hispanics of Caribbean descent have higher stroke risk than white neighbors
Get With The Guidelines Patient Education Materials

For more news at ASA International Stroke Conference 2021, follow us on Twitter @HeartNews #ISC21.

Statements and conclusions of studies that are presented at the American Heart Association's scientific meetings are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers are available here, and the Association's overall financial information is available here.

The American Stroke Association's International Stroke Conference (ISC) is the world's premier meeting dedicated to the science and treatment of cerebrovascular disease. ISC 2021 will be held virtually, March 17-19, 2021. The 3-day conference features more than 1,200 compelling presentations in 21 categories that emphasize basic, clinical and translational sciences as they evolve toward a better understanding of stroke pathophysiology with the goal of developing more effective therapies. Engage in the International Stroke Conference on social media via #ISC21.

About the American Stroke Association

The American Stroke Association is devoted to saving people from stroke -- the No. 2 cause of death in the world and a leading cause of serious disability. We team with millions of volunteers to fund innovative research, fight for stronger public health policies and provide lifesaving tools and information to prevent and treat stroke. The Dallas-based association officially launched in 1998 as a division of the American Heart Association. To learn more or to get involved, call 1-888-4STROKE or visit stroke.org. Follow us on Facebook, Twitter.

The world's oldest crater from a meteorite isn't an impact crater after all

UNIVERSITY OF WATERLOO

Research News

 

Several years after scientists discovered what was considered the oldest crater a meteorite made on the planet, another team found it's actually the result of normal geological processes.

During fieldwork at the Archean Maniitsoq structure in Greenland, an international team of scientists led by the University of Waterloo's Chris Yakymchuk found the features of this region are inconsistent with an impact crater. In 2012, a different team identified it as the remnant of a three-billion-year-old meteorite crater.

"Zircon crystals in the rock are like little time capsules," said Yakymchuk, a professor in Waterloo's Department of Earth and Environmental Sciences. "They preserve ancient damage caused by shockwaves you get from a meteorite impact. We found no such damage in them."

Additionally, there are multiple places where the rocks melted and recrystallized deep in the Earth. This process--called metamorphism--would occur almost instantaneously if produced from an impact. The Waterloo-led team found it happened 40 million years later than the earlier group proposed.

"We went there to explore the area for potential mineral exploration, and it was through close examination of the area and data collected since 2012 that we concluded the features are inconsistent with a meteorite impact," Yakymchuk said. "While we were disappointed that we weren't working in a structure that was the result of a meteorite hitting the planet three billion years ago, science is about advancing knowledge through discovery, and our understanding of the Earth's ancient history continues to evolve. Our findings provide scientific data for resource companies and Greenlandic prospectors to find new mineral resources."

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The study, Stirred not shaken; critical evaluation of a proposed Archean meteorite impact in West Greenland, by Yakymchuk and an international team of scientists from Canada, Australia, Denmark, Greenland and the United Kingdom, appears in the journal Earth and Planetary Science Letters.

The narwhal's tusk reveals its past living conditions

AARHUS UNIVERSITY

Research News

 NEWS RELEASE 11-MAR-2021

 

IMAGE: NARWHALS WITH THEIR CHARACTERISTIC SPIRALLED TUSKS IN DENSE PACK ICE. view more 

CREDIT: PHOTO: ©PAUL NICKLEN / PAULNICKLEN.COM

Every year, a new growth layer is added to the narwhal's spiralled tusk. The individual layers act as an archive of data that reveals what and where the animal has eaten, providing a glimpse of how the ice and environmental conditions have changed over its long life span (up to 50 years).

Same as rings in a tree trunk, every year a new growth layer is added to the narwhal's tusk, which grows longer and thicker throughout the animals life. Because the tusk is connected to the rest of body through blood, each new growth layer records aspects of animal physiology during the year it was formed.

An international team of researchers has now studied each individual growth layer of the tusks from ten narwhals from North-West Greenland. They specifically analysed mercury and stable isotopes of carbon and nitrogen to give information on what the whales have eaten in each year of their life and how the ice cover and the impact of potential toxic compounds such as mercury have changed over time.

A historical archive

Most people are familiar with the narwhal's impressive unicorn-like tusk (a canine tooth) that projects from the left side of the upper jaw of the males.

Researchers do not fully agree on the purpose of the impressive narwhal tusk. Indications from recent years' research suggest that the tusk may be used when the narwhals search for food. But presumably the males also use the long tusk to impress the females. And it is, indeed, impressive - this spiralled, pointed tusk can reach up to three metres long.

Researchers have now shown that each layer of the tusk offers valuable data on the animals' living conditions from when they are born until they die.

"It is unique that a single animal in this way can contribute with a 50-year long-term series of data. It is often through long time series that we as researchers come to understand the development of biological communities, and such series of unbroken data are very rare. Here, the data is a mirror of the development in the Arctic," tells Professor Rune Dietz from the Department of Bioscience and the Arctic Research Centre, Aarhus University, Denmark, who headed the studies.

The sensational data is just published in the journal Current Biology.

CAPTION

Cut-through narwhal tusk displaying the individual year rings. Analyses of the individual layers of narwhal tusks have provided information about their food choice and their exposure to mercury throughout their life.

CREDIT

Photo: Rune Dietz.

Mercury and climate change affect the top link in the food chain

Among the biggest threats to Arctic top predators, such as the polar bear, white whale and narwhal are climate change and the amount of mercury consumed by the animals.

"The higher you are in the food chain, the more mercury you accumulate into your body throughout your life. Heavy metals and other environmentally contaminants accumulate at each link in the food chain, so if you are at the top of the food chain, you end up consuming the greatest amount of mercury at each meal" explains Post-Doctoral Research Fellow Jean-Pierre Desforges, Natural Resource Department, McGill University, Canada, who has co-headed the study.

Elevated amounts of heavy metals in the body are toxic and affect the cognitive functions, behaviour and ability of a species to reproduce and defend against infections.

In 2017, the UN adopted the Minamata Convention, which attempts to limit global mercury pollution.

In the Arctic, climate change over the past 30-40 years has led to less sea ice. Many species depend on the ice when searching for food, for example polar bears, while other species use the ice as important breeding grounds, for example seals. For the narwhal, the ice acts as a protection against enemies like killer whales.

Changes in temperature and the cover of sea ice also lead to invasion by new species from warmer areas. This affects the entire Arctic food chain and thus the living conditions of the individual species.

CAPTION

Data on δ13C, δ15N and mercury in narwhal tusks measured in layers corresponding to the period 1968-2010. The cover of summer sea ice for the same period is also shown.

CREDIT

Aarhus University, Denmark

Revealing analyses

"We have been able to trace this development in the narwhals' tusks. In each layer of the tusk, we measured the amount of mercury, just as we measured stable isotopes of carbon and nitrogen - the so-called delta 13C (δ13C) and delta 15N (δ15N)," says Rune Dietz.

The composition of the carbon and nitrogen isotopes in a layer of the tusk provides insight into the diet of each narwhal in the year from which the actual layer originated. Or rather, how high in the food the prey was, and in which part of the ocean the animals lived.

A low δ15N value indicates how high in the food chain the animal sits. A high δ13C value reflects that the prey is closely linked to the surrounding sea ice, while a low delta δ13C value reflects that the prey has lived in the open sea.

Changing conditions for Arctic top predators

The tusks analysed by the researchers were 150 to 248 cm long and contained data from 1962 to 2010.

"What we found in narwhal of Northwest Greenland is consistent with a more general trend across the Arctic where sea-ice is declining and changing the spatial distribution of sub-Arctic and Arctic fish as well as top predators. The big question now is how these changes will affect the health and fitness of key Arctic species in the years to come," says Jean-Pierre Desforges

The analyses of the tusks revealed three things in particular:

Up until around 1990, the narwhals' food consisted particularly of prey linked to the sea ice, such as halibut and Arctic cod. During this period, the ice cover was extensive but varying.

After 1990, the ice cover in North-West Greenland decline consistently year after year and the diet of the narwhals changed to a dominance of open ocean prey like capelin and polar cod. From 1990 until 2000, narwhals also accumulated relatively small quantities of mercury as the new items of prey sat lower in the food chain.

However, from around 2000, the amount of mercury increased significantly in the narwhal tusks without a simultaneous shift in food items. The researchers have also measured higher levels of mercury in other Arctic animals over the past few decades, and they attribute this to extensive emission of mercury primarily from the coal combustion in South-East Asia. The rise in mercury might also be due to changing sea ice conditions in the Arctic as the climate is warming, causing changes in the environmental mercury cycle in the Arctic.

A bank of data

The development worries Rune Dietz and Jean-Pierre Desforges.

"The narwhal is the Arctic mammal most affected by climate change. At the same time, whales lack the physiological properties to eliminate environmentally contaminants. They don't get rid of mercury by forming hair and feathers like polar bears, seals and seabirds, just as their enzyme system is less efficient at breaking down organic pollutants," explains Rune Dietz.

However, the researchers behind the study see it as a positive sign that the narwhal has a greater ability to change its food basis than previously believed.

"With our new discoveries, we now know that there is a bank of data in the narwhal tusks found in museums around the world. By analysing them, we can hopefully get an insight into the narwhals' food strategy from different areas and periods many years back in time. This will provide us with a solid basis for evaluating how the species copes with the changed conditions that it now encounters in the Arctic," says Rune Dietz.

The research team points out that valuable, chronological information is also waiting in other types of biological material, for example from the teeth of other species, hair, whale baleen, whale earwax plugs, shells from shellfish and year rings in trees.

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By Peter Bondo

Further information:

Professor Rune Dietz, Department of Bioscience - Marine Mammals Research, Aarhus University; Denmark, E-mail: rdi@bios.au.dk; tel.: +45 2125 4035.

Post-Doctoral Research Fellow Jean-Pierre Desforges, Natural Resource Department, McGill University, Canada; E-mail: jean-pierre.desforges@mcgill.ca.

Cheaper carbon capture is on the way

PNNL-developed solvent breaks barriers, 

captures carbon for less than industrial counterparts

DOE/PACIFIC NORTHWEST NATIONAL LABORATORY

NEWS RELEASE 11-MAR-2021

Research News

     

IMAGE: THIS ANIMATION DEPICTS THE TWO-STAGE FLASH CONFIGURATION, ONE OF SEVERAL PROCESSES DESCRIBED IN A NEW STUDY DETAILING HOW EEMPA, A PACIFIC NORTHWEST NATIONAL LABORATORY-DEVELOPED SOLVENT, CAN CAPTURE CARBON FROM FLUE... view more CREDIT: (ANIMATION BY MICHAEL PERKINS | PACIFIC NORTHWEST NATIONAL LABORATORY)

RICHLAND, Wash.--As part of a marathon research effort to lower the cost of carbon capture, chemists have now demonstrated a method to seize carbon dioxide (CO2) that reduces costs by 19 percent compared to current commercial technology. The new technology requires 17 percent less energy to accomplish the same task as its commercial counterparts, surpassing barriers that have kept other forms of carbon capture from widespread industrial use. And it can be easily applied in existing capture systems.

In a study published in the March 2021 edition of International Journal of Greenhouse Gas Control, researchers from the U.S. Department of Energy's Pacific Northwest National Laboratory--along with collaborators from Fluor Corp. and the Electric Power Research Institute--describe properties of the solvent, known as EEMPA, that allow it to sidestep the energetically expensive demands incurred by traditional solvents.

"EEMPA has some promising qualities," said chemical engineer Yuan Jiang, lead author of the study. "It can capture carbon dioxide without high water content, so it's water-lean, and it's much less viscous than other water-lean solvents."

Carbon capture methods are diverse. They range from aqueous amines--the water-rich solvents that run through today's commercially available capture units, which Jiang used as an industrial comparison--to energy-efficient membranes that filter CO2 from flue gas emitted by power plants.

Current atmospheric CO2 levels have soared higher in recent years than at any point within the last 800,000 years, as a new record high of 409.8 parts per million was struck in 2019. CO2 is primarily released through human activities like fossil fuel combustion, and today's atmospheric concentrations exceed pre-industrial levels by 47 percent.

At a cost of $400-$500 million per unit, commercial technology can capture carbon at roughly $58.30 per metric ton of CO2, according to a DOE analysis. EEMPA, according to Jiang's study, can absorb CO2 from power plant flue gas and later release it as pure CO2 for as little as $47.10 per metric ton, offering an additional technology option for power plant operators to capture their CO2.

Jiang's study described seven processes that power plants can adopt when using EEMPA, ranging from simple setups similar to those described in 1930s technology, to multi-stage configurations of greater complexity. Jiang modeled the energy and material costs to run such processes in a 550-megawatt coal power plant, finding that each method coalesces near the $47.10 per metric ton mark.

Solving a solvent's problems

One of the first known patents for solvent-based carbon capture technology cropped up in 1930, filed by Robert Bottoms.

"I kid you not," said green chemist David Heldebrant, coauthor of the new study. "Ninety-one years ago, Bottoms used almost the same process design and chemistry to address what we now know as a 21st century problem."

The chemical process for extracting CO2 from post-combustion gas remains largely unchanged: water-rich amines mix with flue gas, absorb CO2 and are later stripped of the gas, which is then compressed and stored. But aqueous amines have limitations. Because they're water-rich, they must be boiled at high temperatures to remove CO2 and then cooled before they can be reused, driving costs upward.

"We wanted to hit it from the other side and ask, why are we not using 21st century chemistry for this?" Heldebrant said. So, in 2009, he and his colleagues began designing water-lean solvents as an alternative. The first few solvents were too viscous to be usable.

"'Look,'" he recalled industry partners saying, "'your solvent is freezing and turning into glass. We can't work with this.' So, we said, OK. Challenge accepted."

Over the next decade, the PNNL team refined the solvent's chemistry with the explicit aim to overcome the "viscosity barrier." The key, it turned out, was to use molecules that aligned in a way that promoted internal hydrogen bonding, leaving fewer hydrogen atoms to interact with neighboring molecules.

Heldebrant draws a comparison to children running through a ball pit: if two kids hold each other's hands while passing through, they move slowly. But if they hold their own hands instead, they pass as two smaller, faster-moving objects. Internal hydrogen bonding also leaves fewer hydrogen atoms to interact with overall, akin to removing balls from the pit.

Pivoting to plastic

Where the team's solvent was once viscous like honey, it now flowed like water from the kettle. EEMPA is 99 percent less viscous than PNNL's previous water-lean formulations, now nearly on par with commercial solvents, allowing them to be utilized in existing infrastructure, which is largely built from steel. Pivoting to plastic in place of steel, the team found, can further reduce equipment costs.

Steel is expensive to produce, costly to ship and tends to corrode over time in contact with solvents. At one tenth the weight, substituting plastic for steel can drive the overall cost down another $5 per metric ton, according to a study led by Jiang in 2019.

Pairing with plastic offers another advantage to EEMPA, whose reactive surface area is boosted in plastic systems. Because traditional aqueous amines can't "wet" plastic as well (think of water beading on Teflon), this advantage is unique to the new solvent.

The PNNL team plans to produce 4,000 gallons of EEMPA in 2022 to analyze at a 0.5-megawatt scale inside testing facilities at the National Carbon Capture Center in Shelby County, Alabama, in a project led by the Electric Power Research Institute in partnership with Research Triangle Institute International. They will continue testing at increasing scales and further refine the solvent's chemistry, with the aim to reach the U.S. Department of Energy's goal of deploying commercially available technology that can capture CO2 at a cost of $30 per metric ton by 2035.

This study, "Techno-economic comparison of various process configurations for post-combustion carbon capture using a single-component water-lean solvent," was funded by the U.S. Department of Energy Office of Fossil Energy.

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the U.S. Department of Energy's Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE's Office of Science is working to address some of the most pressing challenges of our time. For more information, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

With masks on, three feet is just as safe as six feet apart in Massachusetts schools

Statewide study showed no significant differences in COVID-19 case rates between K-12 districts that implemented 3-feet versus 6-feet of physical distancing

BETH ISRAEL DEACONESS MEDICAL CENTER

Research News

 

BOSTON - As COVID-19 infection rates continue to fall, Massachusetts officials are signaling it's almost time to end remote learning and send all school-aged children back to the classroom. While emerging data suggest young children and schools have not been primary drivers of the COVID-19 pandemic, evidence to guide best practices to prevent the spread of the virus in the school setting has been limited and, as a result, national and international recommendations are inconsistent.

A study led by Beth Israel Deaconess Medical Center (BIDMC) physician-researchers provides new, much-needed data about the optimal physical distancing between students for the prevention of COVID-19 in the school setting. In a retrospective, statewide cohort study, the researchers compared the rates of COVID-19 cases in students and staff in Massachusetts public schools among districts with universal mask mandates but different physical distancing requirements. The team found no substantial difference in the number of cases of COVID-19 among either students or staff in school districts that implemented a distancing policy of three feet versus six feet between students. The findings, published in the journal Clinical Infectious Diseases, suggest that lower physical distancing policies can be adopted in school settings with masking mandates without negatively impacting student or staff safety.

"Prior studies have not directly compared the impact of different physical distancing policies among students attending in-person school," said lead author Polly van den Berg, MD, a fellow in the Division of Infectious Diseases at BIDMC. "This research, which found no substantial difference in the number of cases among either students or staff in school districts that implemented a distancing policy of three versus six feet between students, is important because many school buildings have physical infrastructure that cannot accommodate six feet of distancing and bring all (or most) students back into the classroom."

Van den Berg and colleagues looked at publicly available data from 251 Massachusetts school districts, encompassing 537,336 students and 99,390 staff who attended in-person instruction during a 16-week study period from September 2020 to January 2021. Using a combination of information - including individual district infection control plans, the number of infections reported to the Commonwealth by districts, and community rates of COVID-19 from a non-partisan, not-for-profit data dashboard - the scientists found no significant difference in the rate of COVID-19 cases among students and staff in districts that mandated six feet of distancing versus in districts that mandated three feet of distancing. The scientists note that physical distancing was only one of several infection prevention measures taken by school districts.

"These data can be used to inform and update how infection control plans are implemented in school settings," added corresponding author Westyn Branch-Elliman, MD, MMSc, an infectious disease specialist at BIDMC and a clinical investigator at VA Boston Healthcare System. "It is important to remember that distancing was just one of a number of interventions adopted in the districts included in our analysis. Across the districts included in our study, there was a near-universal masking mandate, thus our study addresses the question of the effectiveness of three versus six feet of distancing among students and staff who are wearing masks."

The team's findings also showed that, in general, schools had lower overall rates of infection than their surrounding communities, lending support to the idea that in-person learning is not a major driver of the pandemic; however, district case rates were tightly linked to those of the community, particularly among staff.

"Early in the pandemic, infection control plans for schools and other settings were developed based on the best available evidence at the time -- which, early on, was limited," said Branch-Elliman, also an Assistant Professor of Medicine at Harvard Medical School. "We hope that our findings can be used to update current recommendations about distancing policy, and ultimately, to help return more students to the classroom."

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Co-authors include Elissa M. Schechter-Perkins, MD, MPH, of Boston University School of Medicine and Boston Medical Center; Rebecca S. Jack, MPP of COVID-19 School Response Dashboard; Isabella Epshtein, MPP, of VA Boston Center for Healthcare Organization and Implementation Research; Richard Nelson, PhD, Veterans Affairs Salt Lake City Healthcare System and University of Utah School of Medicine; and Emily Oster, PhD, of COVID-19 School Response Dashboard and Brown University Watson Institute for International and Public Affairs.

The authors received no financial support for the research, authorship, and/or publication of this article. WBE is the site PI for a grant funded by Gilead pharmaceuticals (funds to institution). EO and RJ are affiliated with the COVID-19 School Dashboard, which is funded in part by the Chan Zuckerberg Foundation and the Arnold Foundation. All other authors have no conflicts to report.

About Beth Israel Deaconess Medical Center

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School and consistently ranks as a national leader among independent hospitals in National Institutes of Health funding. BIDMC is the official hospital of the Boston Red Sox. For more information, visit http://www.bidmc.org.

Beth Israel Deaconess Medical Center is a part of Beth Israel Lahey Health, a health care system that brings together academic medical centers and teaching hospitals, community and specialty hospitals, more than 4,000 physicians and 35,000 employees in a shared mission to expand access to great care and advance the science and practice of medicine through groundbreaking research and education.