air pollution and health

EPA’s MESA Air Study Confirms that Air Pollution Contributes to the #1 Cause of Death in the U.S.

By Dr. Wayne Cascio

This week we took a giant leap forward in our understanding of the relationship between air pollution and heart disease with the publication of results from the Multi-Ethnic Study of Atherosclerosis Air Pollution Study (MESA Air) in the leading medical journal The Lancet.

medical graphic of a coronary artery

Fat accumulation in the wall of a coronary artery

For more than two decades, scientific evidence has shown fine particle pollution (PM2.5) in the outside air is a cause of cardiovascular illness and death, and has justified improving the PM2.5 annual National Ambient Air Quality Standard to protect public health.  Yet, MESA Air was the first U.S. research study to examine a group of people over a period of 10 years and measured directly how long-term exposure to air pollution contributes to the development of heart disease and can lead to heart attacks, abnormal heart rhythms, heart failure, and death.  MESA Air did just that, and Dr. Joel Kaufman, the leader of MESA Air at the University of Washington and his colleagues should be commended for their accomplishment.

MESA Air was funded by EPA and made possible by the National Heart, Lung, and Blood Institute, which supports  a larger study on atherosclerosis called MESA. The additional air pollution study had the ambitious goal of seeking an answer to the question of whether long-term exposure to PM2.5 and nitrogen oxides (NOx) was associated with the development and progression of cardiovascular disease.  A total of 6,800 people with diverse racial and ethnic backgrounds and residing in six locations throughout the country agreed to participate in the decade-long study by researchers at the University of Washington who received the grant.  And the results are in!

The researchers used computerized tomography imaging to measure coronary artery calcium content in the same person repeatedly during the study as an indication of coronary artery disease. The results showed that long-term exposure to PM2.5 and NOx increased coronary artery calcium. The increase observed is at a rate that, over the period of the study, would change the risk of heart attack in some.

This study is extraordinary in many ways. First it provides the strongest evidence yet that air pollution can and does contribute to cardiovascular disease–the number one killer of Americans and people in developed countries throughout the world.  Secondly, the results define the relationship between air pollutants and the progression of coronary artery disease over time.  This relationship will help estimate the long-term health impacts and economic burden of air pollution within our population.   And, third the study shows the power of intra-agency cooperation to conduct valuable and cost-effective science.

The findings of MESA Air will continue to reverberate throughout the environmental science and public health communities for some time, but it’s time for healthcare providers, air quality managers and state and local planners to take note and to begin to consider long-term exposure to air pollution as having long-term health implications, even at levels near the National Ambient Air Quality Standards.

About the Author: Dr. Wayne Cascio spent more than 25 years as a cardiologist before joining EPA’s Office of Research and Development where he now leads research on the links between exposures to air pollution and public health, and how people can use that information to maintain healthy hearts.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Simulating Wildland Fires in a Tube to Protect Public Health

By Dina Abdulhadi

After a long day of backpacking in the woods, I always look forward to watching the story arc of a campfire. The flames grow slowly, then leap up as the fire builds momentum. As the fire calms, the logs smolder and glow with heat.

Wildfires have similar phases. During an active fire, flames rapidly move over the landscape. The remaining embers can smolder on for days to weeks after the fire front passes, depending on what trees or other vegetation are there to fuel the fire. These two factors—what is burning and whether it’s flaming or smoldering—affect the smoke that people ultimately breathe.

To study the potential health risks of breathing wildfire smoke, a major form of air pollution, researchers at EPA are now using a technology that mimics these phases of a fire in a laboratory in Research Triangle Park, N.C. Originally developed to investigate tobacco’s health effects, this Biomass Furnace System allows researchers to study the chaotic nature of fire in a controlled setting and compare emissions from different trees during the fire and smoldering stages. Knowing these differences will provide more information to protect public health and enable air quality managers to prepare for the increased wildfires we expect in the future due to climate change and drought.

Tube used to conduct simulation

Biomass Fuel Combustion System

 

Particulate matter (PM) is one of the main pollutants created by fire. These tiny particles are produced when anything is burned—whether that’s the logs to your campfire or gasoline ignited to fuel your car’s engine. Many studies have linked it to effects on the heart and lungs.

During 2011, wildfires and controlled burns alone contributed up to 41 percent of emitted PM pollution in the U.S. This pollution can have drastic effects on the local community, but it can also affect the air breathed by those far away as the smoke drifts.

To understand the growing impact of wildfires on human health, researchers plan to look at effects on the heart, nervous system (such as headaches), and respiratory system from a variety of wood fuels by using models. They’ll also investigate if PM from wildfire smoke is more or less harmful than PM from other sources of air pollution, like car exhaust.

map of potential fires across US

Map showing distribution of potential wildfire fuels across the United States (Credit: Yongho Kim)

According to the National Fire Center, two fires are burning right now in my state of North Carolina alone. When you consider what could be happening in the other 49 states as well, this kind of research becomes that much more valuable for scientists working to protect public health.

Want to learn more about the research EPA conducts on wildfires to protect human health and the environment? Listen to our Science Bite Podcast Following the Smoke: Wildfires and Health.

About the author: Dina Abdulhadi is a student contractor working with the science communication team in EPA’s Office of Research and Development.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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This Week in EPA Science

By Kacey Fitzpatrickresearch_recap_GI_stPatricks

St. Patrick’s Day not enough green for you? Then check out the latest in environmental science from EPA!

High-Throughput Research on Flame Retardants in Zebrafish
EPA researcher Dr. Pamela Noyes recently won the Best Postdoctoral Publication at the 2016 Society of Toxicology Conference for her paper titled, “Advanced morphological – behavioral test platform reveals neurodevelopmental defects in embryonic zebrafish exposed to comprehensive suite of halogenated and organophosphate flame retardants. Dr. Noyes’ study shows that exposure to certain flame retardants is potentially associated with various neurological changes in zebrafish. Read more about her research in the blog One Fish, Two Fish, Test Fish, Control Fish.

Olive Oil and Fish Oil: Possible Protectors against Air Pollution
Ever wondered what’s so healthy about taking fish oil tablets? EPA scientist Dr. Samantha J. Snow is investigating one of the potential benefits. Her recent research looks at how these oils in the diet might change the body’s reaction to exposure to ozone, a common outdoor air pollutant. Read more about her research in the blog Olive Oil and Fish Oil: Possible Protectors against Air Pollution.

Interviews with EPA’s Thomas Burke
EPA Science Advisor and Deputy Assistant Administrator for the Office of Research and Development, Dr. Thomas Burke, was recently interviewed for the American Thoracic Society’s Research News Quarterly. Dr. Burke also talked to Bloomberg BNA about the role he envisions for public health in environmental decision-making.

Upcoming Events
Interested in what’s happening at EPA this month? Check out the Events to watch for in March blog to learn about a few public meetings and webinars you can attend! You can also read about an upcoming webinar highlighting a research funding opportunity in the blog Integrating Human Health and Well-Being with Ecosystem Services.

About the Author: Kacey Fitzpatrick is a student contractor and writer working with the science communication team in EPA’s Office of Research and Development.

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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OnAir@AAAR: Ironing out Trace Metal Measurements

Michelle Oakes has developed a new instrument to more accurately measure a dangerous air pollutant: Iron (II).
Oakes, an EPA STAR grantee and scientist at the Georgia Institute of Technology, presented the new instrument Monday at the 2010 AAAR conference on air pollution and health.

blog_ironII_michelle oakes

Iron (II) is commonly emitted by sources like biomass burning and coal-fired power plants and is associated with the production of harmful reactive oxygen species in the body. Oakes’ device, called a Particle-to-Liquid Sampler, measures the dangerous trace metal significantly better than previous methods ever have.

“People usually use a filter that works over 24 hours to measure Iron (II),” Oakes explained.
“But what we found is that the filters underestimate Iron (II) by a lot.”

She reported that in some cases, the Particle-to-Liquid Sampler measured Iron (II) levels twice as high as those measured by the filters—a very significant difference.

Because the Sampler conducts automated measurements every 12 minutes, it does a better job than 24-hour filters at capturing changes in Iron (II) levels throughout the day.

As wind speeds change, it is common for Iron (II) levels to fluctuate, producing what Oakes calls “transient events,” or periods of time where iron levels oscillate strongly from high to low.

The average daily Iron (II) measurements produced from the filters tend to mask these fluctuations.
Oakes explained that her device and its ability to more accurately reflect Iron (II) variations over time could significantly benefit the public health community.

“From a health standpoint,” Oakes said, “you need something that’s reliable…you want to be able to see the times of day when it’s most dangerous for people to be outdoors.”

But there are additional advantages to the “totally new” device.
“Not only does it do a better job measuring variations, but it’s also much less labor intensive than using filters which require lots of hours and work,” Oakes pointed out.

Once adapted to become more easily deployable, the sampler could potentially help States measure trace metals more easily.
Oakes presented the work during Monday’s AAAR poster session and seemed pleased to share the new technology.
“I really enjoy working on this,” Oakes said smiling, “it’s a way to do chemistry, be outdoors, and make an impact.”

AAAR_intro

About the Author: Becky Fried is a science writer with EPA’s National Center for Environmental Research. Her OnAir posts are a regular “Science Wednesday” feature.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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