Science Current Events | Science News | Brightsurf.com
 

Elevated Indoor Carbon Dioxide Impairs Decision-Making Performance

October 18, 2012

Overturning decades of conventional wisdom, researchers at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have found that moderately high indoor concentrations of carbon dioxide (CO2) can significantly impair people's decision-making performance. The results were unexpected and may have particular implications for schools and other spaces with high occupant density.

"In our field we have always had a dogma that CO2 itself, at the levels we find in buildings, is just not important and doesn't have any direct impacts on people," said Berkeley Lab scientist William Fisk, a co-author of the study, which was published in Environmental Health Perspectives online last month. "So these results, which were quite unambiguous, were surprising." The study was conducted with researchers from State University of New York (SUNY) Upstate Medical University.

On nine scales of decision-making performance, test subjects showed significant reductions on six of the scales at CO2 levels of 1,000 parts per million (ppm) and large reductions on seven of the scales at 2,500 ppm. The most dramatic declines in performance, in which subjects were rated as "dysfunctional," were for taking initiative and thinking strategically. "Previous studies have looked at 10,000 ppm, 20,000 ppm; that's the level at which scientists thought effects started," said Berkeley Lab scientist Mark Mendell, also a co-author of the study. "That's why these findings are so startling."

While the results need to be replicated in a larger study, they point to possible economic consequences of pursuing energy efficient buildings without regard to occupants. "As there's a drive for increasing energy efficiency, there's a push for making buildings tighter and less expensive to run," said Mendell. "There's some risk that, in that process, adverse effects on occupants will be ignored. One way to make sure occupants get the attention they deserve is to point out adverse economic impacts of poor indoor air quality. If people can't think or perform as well, that could obviously have adverse economic impacts."

The primary source of indoor CO2 is humans. While typical outdoor concentrations are around 380 ppm, indoor concentrations can go up to several thousand ppm. Higher indoor CO2 concentrations relative to outdoors are due to low rates of ventilation, which are often driven by the need to reduce energy consumption. In the real world, CO2 concentrations in office buildings normally don't exceed 1,000 ppm, except in meeting rooms, when groups of people gather for extended periods of time.

In classrooms, concentrations frequently exceed 1,000 ppm and occasionally exceed 3,000 ppm. CO2 at these levels has been assumed to indicate poor ventilation, with increased exposure to other indoor pollutants of potential concern, but the CO2 itself at these levels has not been a source of concern. Federal guidelines set a maximum occupational exposure limit at 5,000 ppm as a time-weighted average for an eight-hour workday.

Fisk decided to test the conventional wisdom on indoor CO2 after coming across two small Hungarian studies reporting that exposures between 2,000 and 5,000 ppm may have adverse impacts on some human activities.

Fisk, Mendell, and their colleagues, including Usha Satish at SUNY Upstate Medical University, assessed CO2 exposure at three concentrations: 600, 1,000 and 2,500 ppm. They recruited 24 participants, mostly college students, who were studied in groups of four in a small office-like chamber for 2.5 hours for each of the three conditions. Ultrapure CO2 was injected into the air supply and mixing was ensured, while all other factors, such as temperature, humidity, and ventilation rate, were kept constant. The sessions for each person took place on a single day, with one-hour breaks between sessions.

Although the sample size was small, the results were unmistakable. "The stronger the effect you have, the fewer subjects you need to see it," Fisk said. "Our effect was so big, even with a small number of people, it was a very clear effect."

Another novel aspect of this study was the test used to assess decision-making performance, the Strategic Management Simulation (SMS) test, developed by SUNY. In most studies of how indoor air quality affects people, test subjects are given simple tasks to perform, such as adding a column of numbers or proofreading text. "It's hard to know how those indicators translate in the real world," said Fisk. "The SMS measures a higher level of cognitive performance, so I wanted to get that into our field of research."

The SMS has been used most commonly to assess effects on cognitive function, such as by drugs, pharmaceuticals or brain injury, and as a training tool for executives. The test gives scenarios-for example, you're the manager of an organization when a crisis hits, what do you do?-and scores participants in nine areas. "It looks at a number of dimensions, such as how proactive you are, how focused you are, or how you search for and use information," said Fisk. "The test has been validated through other means, and they've shown that for executives it is predictive of future income and job level."

Data from elementary school classrooms has found CO2 concentrations frequently near or above the levels in the Berkeley Lab study. Although their study tested only decision making and not learning, Fisk and Mendell say it is possible that students could be disadvantaged in poorly ventilated classrooms, or in rooms in which a large number of people are gathered to take a test. "We cannot rule out impacts on learning," their report says.

The next step for the Berkeley Lab researchers is to reproduce and expand upon their findings. "Our first goal is to replicate this study because it's so important and would have such large implications," said Fisk. "We need a larger sample and additional tests of human work performance. We also want to include an expert who can assess what's going on physiologically."

Until then, they say it's too early to make any recommendations for office workers or building managers. "Assuming it's replicated, it has implications for the standards we set for minimum ventilation rates for buildings," Fisk said. "People who are employers who want to get the most of their workforce would want to pay attention to this."

Funding for this study was provided by SUNY and the state of New York.

Lawrence Berkeley National Laboratory


Related Carbon Dioxide Current Events and Carbon Dioxide News Articles


Aggregated protein in nerve cells can cause ALS
Persons with the serious disorder ALS, can have a genetic mutation that causes the protein SOD1 to aggregate in motor neurons in the brain and spinal cord.

Demographic changes increase the risk of natural fires
In many parts of the world, grass and forest fires pose a threat to animals and humans. According to a new study from Lund University in Sweden, while climate change is likely to cause more and larger fires, in the future, more and more people will become directly affected as a result of demographic changes.

New study found ocean acidification may be impacting coral reefs in the Florida keys
In a new study, University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science researchers found that the limestone that forms the foundation of coral reefs along the Florida Reef Tract is dissolving during the fall and winter months on many reefs in the Florida Keys.

Improving utilization of ammonia and carbon dioxide in microalgal cultivation
Algaculture or algae farming, like any form of agriculture, is highly sensitive to fertilizer costs. A major roadblock to commercial algae farming is efficient utilization of volatile nutrients, specifically ammonia and carbon dioxide (CO2), to feed the algae being farmed.

Could global warming's top culprit help crops?
Many scientists fear that global warming will hit staple food crops hard, with heat stress, extreme weather events and water shortages.

Clear-cutting destabilizes carbon in forest soils, Dartmouth study finds
Clear-cutting loosens up carbon stored in forest soils, increasing the chances it will return to the atmosphere as carbon dioxide and contribute to climate change, a Dartmouth College study shows.

Water cycle instability is here to stay posing major political and economic risks: UN Experts
The current instability and unpredictability of the world water cycle is here to stay, making society's adaptation to new risks a vital necessity when formulating development policies, a UN water expert warns.

North Atlantic played pivotal role in last great climate tipping point
North Atlantic played pivotal role in last great climate tipping point, research shows.

Western lifestyle spells the end of biodiversity
Contrary to what many economists suggest (see, for example, an article in The Economist entitled Hang On, published in September 2013) "development is not always good for Nature", a biologist at Tomsk State University argues. It is broadly accepted that biodiversity and the ecosystem are both fundamental to sustaining humanity and life on Earth, but in recent centuries they have been subject to heavy pressures due to overexploitation.

NASA examines El Nino's impact on ocean's food source
El Nino years can have a big impact on the littlest plants in the ocean, and NASA scientists are studying the relationship between the two.
More Carbon Dioxide Current Events and Carbon Dioxide News Articles

Miracle Molecule: Carbon Dioxide, Gas of Life

Miracle Molecule: Carbon Dioxide, Gas of Life
by CFACT


The astonishing story of a simple chemical that made life on Earth possible and continues its work today. Tiny amounts of this miracle molecule not only make life on Earth possible, but rising atmospheric CO2 levels also spur forest and crop growth, help plants survive heat and drought, and feed the world.

The Carbon Dioxide Syndrome

The Carbon Dioxide Syndrome
by Jennifer Stark and Russell Stark (Author)


Learn why changing your breathing can improve your health and well-being through the Butekyo Method. This method will help those with sleep disorders, panic attacks, allergies, hypertension and asthma.

The Global Warming, Carbon Dioxide Hoax: Easy to Read Proof That Climate Change Is Normal and Not Man-Made

The Global Warming, Carbon Dioxide Hoax: Easy to Read Proof That Climate Change Is Normal and Not Man-Made
by Burlington National Inc.


Earth’s climate has always changed. 12,000 years ago most of North America was covered in over a mile of ice and the oceans were 400 feet lower! America has been warming ever since. We will continue to warm or we could go back into our current ice age.
Ice ages are bad because food doesn’t grow well and billions of Humans will either starve or freeze to death. Warming is good because we all live and prosper.
There is absolutely no evidence that Humans cause global warming. In fact, only the stars know if it will get hotter or colder and it is all up to that one star we call our sun.

Carbon Dioxide Capture and Storage: Current Status and Future Prospects (Materials and Energy)

Carbon Dioxide Capture and Storage: Current Status and Future Prospects (Materials and Energy)
by Shinichi Nakao (Author), Ziqiu Xue (Author)


This book consists of two parts of capture and storage. The capture part introduces the main carbon dioxide capture technologies: Absorption, adsorption and membrane. The chapter of chemical absorption shows the research results of carbon dioxide capture using novel aqueous amine solutions. Amine-modified solid sorbents and hydrophobic adsorbents are introduced in the adsorption chapter. "Molecular gate membrane" developed by RITE (Research Institute of Innovative Technology for the Earth) is described with the latest research results. Such information is valuable and accelerates the technology progress.
This storage part firstly describes the fundamentals of commonly used monitoring technologies at the carbon dioxide storage sites and then provides detailed field data collected from...

Electrochemical Reduction of Carbon Dioxide: Fundamentals and Technologies (Electrochemical Energy Storage and Conversion)

Electrochemical Reduction of Carbon Dioxide: Fundamentals and Technologies (Electrochemical Energy Storage and Conversion)
by Jinli Qiao (Editor), Yuyu Liu (Editor), Jiujun Zhang (Editor)


This book gives a comprehensive overview of the electrochemical reduction of carbon dioxide. It covers fundamentals and technologies, including the latest materials and newest developments. The authors address a variety of topics that include electrochemical processes, materials, components, manufacturing, and degradation mechanisms, as well as challenges and strategies. With contributions from researchers who are at the top of their fields and on the cutting edge of technology, the book includes in-depth discussions ranging from engineering of components to applied devices.

Carbon Democracy: Political Power in the Age of Oil

Carbon Democracy: Political Power in the Age of Oil
by Timothy Mitchell (Author)


Does oil wealth lead to political poverty? It often looks that way, but Carbon Democracy tells a more complex story. In this magisterial study, Timothy Mitchell rethinks the history of energy, bringing into his grasp as he does so environmental politics, the struggle for democracy, and the place of the Middle East in the modern world. 

With the rise of coal power, the producers who oversaw its production acquired the ability to shut down energy systems, a threat they used to build the first mass democracies. Oil offered the West an alternative, and with it came a new form of politics. Oil created a denatured political life whose central object – the economy – appeared capable of infinite growth. What followed was a Western democracy dependent on an undemocratic Middle East....

  Carbon Dioxide: Problems and Decisions (Applied Mechanics and Materials)
by Ivani S. Bott (Editor)




Natural Extracts Using Supercritical Carbon Dioxide

Natural Extracts Using Supercritical Carbon Dioxide
by Mamata Mukhopadhyay (Author)


Synthesizing research from a wide variety of sources, this work offers a convenient guide to a clean, safe, inexpensive, non-toxic, non-polluting solvent that performs better than most conventional solvents. Natural Extracts Using Supercritical Carbon Dioxide reviews recent development in the technology and its applications to the food, flavor, fragrance, and pharmaceutical industries. It outlines the many advantages the method has over traditional methods like steam distillation, solvent extraction, and molecular distillation and it supports the popular trend toward the use of natural products in these industries.



The Allergy Solution: Unlock the Surprising, Hidden Truth about Why You Are Sick and How to Get Well

The Allergy Solution: Unlock the Surprising, Hidden Truth about Why You Are Sick and How to Get Well
by Leo Galland M.D. (Author), Jonathan Galland J.D. (Author)


     An epidemic of allergies is spreading around the world. One billion people suffer from allergic diseases such as asthma, hay fever, eczema, and food allergies. But this is just the tip of the iceberg. In this groundbreaking book, award-winning doctor Leo Galland, M.D., reveals the shocking rise of hidden allergies that lead to weight gain, fatigue, brain fog, depression, joint pain, headaches, ADHD, digestive problems, and much more. Astonishing new research shows how each of these is linked to the immune imbalance that is at the root of allergy.
     A brilliant clinician, Dr. Galland has unlocked the power of this breakthrough science to help thousands of patients who have struggled with mysterious symptoms answer the question: “Doctor, what’s wrong with me?”...

Carbon Dioxide Thermodynamic Properties Handbook: Covering Temperatures from -20 to 250C and Pressures up to 1000 Bar

Carbon Dioxide Thermodynamic Properties Handbook: Covering Temperatures from -20 to 250C and Pressures up to 1000 Bar
by Sara Anwar (Author), John J. Carroll (Author)


The classic book on corrosion science and engineering-now in a valuable new edition The ability to prevent failures by managing corrosion is one of the main global challengesof the twenty-first century. However, most practicing engineers and technologists have only a basic understanding of how they can actively participate in this urgent economic and environmental issue. Now, students and professionals can turn to this newly revised edition of the trusted Corrosion and Corrosion Control for coverage of the latest developments in the field, including advances in knowledge, new alloys for corrosion control, and industry developments in response to public demand. This Fourth Edition presents an updated overview of the essential aspects of corrosion science and engineering that underpin the...

© 2016 BrightSurf.com