AAAR 2010 Specialty Conference

OnAir: Research Underdogs Fill Atmospheric Blind Spot

AAAR_underdogs1Andy Grieshop and Ben Murphy call themselves underdogs.

“A few years ago when we presented our research… people would just stare at us blankly,” Andy recalled.

But now, several years and publications later, the skeptical tone has changed. During a presentation at the 2010 AAAR conference in San Diego, audience members seemed encouraged by what they saw.

Andy and Ben are two members of a group of Carnegie Mellon scientists who have spent years trying to fill a big blind spot in atmospheric modeling.

Historically, most models of atmospheric air pollution significantly underestimated the amount of a specific kind of particle, called secondary organic aerosol (SOA).

“What we actually observe in the atmosphere is a factor of 3 – 100 times more than the SOA traditional models predict,” Grieshop explained.

This means that the information used by scientists and policymakers to make important pollution control decisions is not representing everything that people breathe.

According to Grieshop and Murphy, the traditional models overlook some key reactions and processes that take place as particles age and transform in the atmosphere. Most people do not breathe particles emitted directly from a tail pipe, they explained. People breathe in particles that have spent time in the air, moving and reacting with other chemicals.

“When particles dilute, evaporate and then condense back to particles, a lot about them changes,” Murphy said.

Some of these changes could be important to human health.

“Health researchers need accurate models to understand what people are actually exposed to,” Murphy said.

If SOA, as some preliminary studies suggest, is more toxic to people, the new models could be critical for protection of public health.

The new model incorporates atmospheric processes that contribute to SOA formation and does a much better job of predicting what people breathe.

“It’s pretty close to right-on,” Grieshop said, “in terms of matching what we observe in the atmosphere.”

Though more research needs to be done to “drill deeper” into atmospheric processes that may change particles, both scientists agree that this finding could have a big impact.

Their research is already being incorporated into state and local air quality models that are used to manage and control pollution.

“You never really expect that your specific research in atmospheric chemistry may be important for national policy so early on in your career,” Grieshop said excitedly.

“This has been a really great opportunity for us to make a difference.”

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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OnAir@AAAR: Wildfire sparks idea in EPA scientist

Bob Devlin was 100 miles away from the Pocosin Lakes National Wildlife Refuge when he looked out a window and noticed something strange.

The thick smog he noticed that day in the summer of 2008 appeared suspicious because it wasn’t smog… it was smoke.

Though far removed, Devlin caught a firsthand glimpse of the smoke plume emanating from a huge wildfire that ravaged over 30,000 acres of eastern North Carolina.

“That was the day that started it all,” Devlin said Wednesday at the AAAR conference.

After the fire, he quickly banded together a large group of scientists to collaborate on an innovative project. He sought to not only study the health effects of such a large fire, but to do so in a way that communities and states could mimic cheaply and easily during future wildfire events.

Using satellite imagery, Devlin and his colleagues looked at every North Carolina county that was covered in smoke during the three worst days of the fire. They also collected easily accessible data on daily emergency room visits during the worst fire days.

Devlin found significant spikes in emergency room visits for asthma, heart failure, arrhythmia, and pneumonia in counties that were covered in smoke during the worst wildfire days.

The data is unique for two reasons. It is the first time such associations between wildfire pollution and emergency room visits due to cardiovascular problems have been made (previously, only respiratory effects were reported). It is also one of the first case studies of a peat fire, which, in contrast to a normal wildfire, emits pollution particles closer to the ground where people may more readily inhale them.

While the findings are interesting in their own right, the larger significance of the study lies in the ability of the public health community to replicate Devlin’s analysis cheaply, easily, and without sophisticated statistical methods.

“Anybody can access these satellite images, count up the counties covered in smoke, and look at emergency room visits,” Devlin explained.

“In the future, public health officials can use this method to make decisions… [they can decide] for example, whether elderly people should be removed from the path of wildfire smoke.”

The next step, Devlin said, is to continue analysis of the 2008 fire by incorporating data on actual hospital admissions.

For an abstract of Devlin’s work, visit

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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OnAir@AAAR: For Policymakers on Panel, Environmental Justice is High Priority

At AAAR’s Wednesday panel on air pollution policy and research, members of local, state, and national air quality regulatory bodies had environmental justice on the mind.

According to EPA, environmental justice “will be achieved when everyone enjoys the same degree of protection from environmental and health hazards and equal access to the decision-making process to have a healthy environment in which to live, learn, and work.”

Throughout the discussion, each of the six panelists tied air pollution research priorities to environmental justice.

Dr. John Balmes, a member of the California Air Resources Board, explained that communities with inadequate access to health care, limited green space, high stress levels, and other factors working against them could be more vulnerable to the effects of air pollution.

“We are serious about protecting these communities from further health effects that could be caused by air pollution,” Balmes said. One way to ensure protection of these highly impacted communities is to incorporate “sociodemographics” into future air pollution research, he explained.

Lydia Wegman, of the office of Air Quality Planning and Standards at EPA, echoed Balmes’ sentiment. She suggested that air pollution scientists approach research on vulnerable communities as “a multidimensional problem.”

Also on the panel was Lenore Lamb, environmental director of the Pala Band of Mission Indians. Though the Pala Band is an autonomous body that can set its own local air quality rules, the tribe must still adhere to federal air quality regulations. Lamb stressed the importance of building sound science, monitoring networks, and data collection in tribal communities that often lack these important building blocks of improved air quality.

Al Armendariz, Regional Administrator for EPA’s Region 6, used part of his time at the microphone to dare an audience full of air pollution scientists to develop “inexpensive, low-cost, self-contained, rain-proof” community air quality monitors to ensure that everyone, even disadvantaged communities, can afford to monitor the air they breathe.

Environmental justice is becoming a priority across all levels of government. Wednesday’s panel was a call to action for air pollution scientists, challenging them to seek out new ways to research air pollution and its health effects on potentially vulnerable communities.

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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OnAir@AAAR: Urban V. Rural—How Do Coarse Particles Compare?

I sat down with Mike Hannigan, EPA grantee and UC Boulder scientist, Tuesday to talk about his innovative research on coarse particles.

mike hannigan

“Coarse particles are basically what we think of as dust,” Hannigan explained.

“But what’s tricky is that depending on where you are, the dust can look very, very different.”

In an urban environment, for example, a large percentage of coarse particle pollution comes from the brake-wear of stopping and slowing vehicles. In rural areas though, agricultural dust and windblown soil play a big role.

“The major question we’re trying to answer is—do these different kinds of coarse particles cause different health effects? And if so, should this impact the way coarse particles are managed in the future?”

A handful of studies have suggested increased hospitalizations for cardiovascular and respiratory illness with exposure to coarse particles, but a comparison of urban and rural effects has never been done before.

Hannigan and colleagues set up monitors in Denver, Colorado and in a rural town called Greeley, about 100 miles to northeast of Denver. The monitors measure both coarse and fine particles continuously, producing hourly averages that give a clear picture of how particle exposures vary over time.

Hannigan’s group has been monitoring for just over a year and will continue for another two. After monitoring is complete, the data will be turned over to epidemiologists to look for any associations between coarse particles and hospitalizations, deaths, and birth outcomes in Denver and Greeley.

“ Nobody has ever looked at birth outcomes as a possible effect of coarse particle exposure before,” Hannigan said, “so this is very new.”

Over the three years of monitoring, Hannigan and colleagues will also collect samples for lab analysis in an effort to determine the origins of coarse particles in each area.

“You can measure barium in samples, for example,” Hannigan explained, “and since brakes are really the only place you find barium… that tells us something about the source of those particles.”
In the future, Hannigan hopes to expand his analysis to include biological sources of coarse particles like pollen and bacteria.

“We can sequence the DNA of particles off the filters from the field and understand more about where they are coming from,” he said.

“It’s all very exciting; it’s going to add a lot of knowledge to the scientific community.”

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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OnAir@AAAR: Kicking off Air Science 40

Dan Costa, national program director of EPA’s Clean Air Research Program, presented Air Science 40 at Tuesday’s AAAR conference lunchtime lecture.

The presentation marked the beginning of a yearlong celebration of 40 years’ worth of air pollution research at EPA.

Over the course of 2010, a five-part Air Science 40 seminar series will take place on Capitol Hill and at EPA Headquarters in Washington, DC. The series will include lectures on the hottest topics in air science by some of the most prominent researchers in the field.

Recognizing the importance of communicating this research to policymakers and the public, the American Heart Association (AHA) and the American Thoracic Society (ATS) have joined the celebration as sponsors of selected seminars. The AHA will use Air Science 40 as a platform to release an important statement from the cardiology community that contains new information on the impacts of air pollution on cardiovascular health.

In another Air Science 40 milestone, the new Clean Air Research Centers—each funded by a multimillion dollar EPA grant—will be revealed in 2010. The Centers will provide the fundamental scientific research EPA needs to develop multi-pollutant policies and manage air quality sustainably. They will also expand the scope of previously funded EPA PM Research Centers, which gave critical new insights into the sources and health effects of outdoor particles.

Another goal of Air Science 40 is to promote an informed public. Americans are directly impacted by regulatory decisions based on air research; they need and deserve to understand the science behind these important decisions.

Air Science 40

Throughout 2010, the public will have new opportunities to learn about air science and how it has directly impacted their lives. A 10-minute documentary film on the history of air pollution research and its major contributions to environmental and human health will be presented at regional meetings and on the web. Print literature and web features will also be widely distributed to increase awareness about timely air quality issues.

Since 1970, EPA has provided the research to support the development and implementation of national air quality standards. The scientific information, tools and technology to reduce and control air pollution are products of air science research. It deserves to be celebrated.

More information about the Clean Air Research Program

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.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Science Wednesday:OnAir@AAAR: For Coarse Particles, is a Single Monitor enough?

Each week we write about the science behind environmental protection. Previous Science Wednesdays.

Payam Pakbin, an EPA grantee and scientist at USC, has recently begun to investigate a controversial topic in air pollution science: coarse particles.

Coarse particles are relatively large, ranging in diameter from 2.5 – 10 micrometers. They come from sources like windblown dust, pollen and fungal spores—which, unlike the combustion sources that produce fine particles, are often extremely difficult to control.

Though there have been preliminary studies on the health effects of coarse particles, there is still a lack of definitive evidence.

EPA scientists are working to bridge this gap in understanding. Until there is a scientific consensus on the health effects of coarse PM, regulations to control it as an isolated pollutant cannot be developed or implemented.

payam pakbin-AAAR

Scientists like Pakbin and his advisor, Costas Sioutas, are beginning to tackle this scientific question and its accompanying challenges. Because coarse PM levels vary significantly over seasons and space, estimating the extent to which people are exposed is very difficult.

By sampling in 10 locations across the Los Angeles Basin once per week for an entire year, Pakbin and Sioutas were able to observe how coarse particle levels changed over space and time. This information is critical to health researchers who need accurate estimates of coarse PM exposure in order to determine the long term effects on human health.

Pakbin found that in the urban locations where pollutants mostly come from the same sources, there was little spatial variability. This suggests that a single, central monitor may be adequate for estimating the amount of coarse PM exposure in a given region. This finding is a boon for health researchers who may now be able to rely on cheap data from central monitors that already exist.

The LA Basin study area makes this work especially significant, Sioutas explained.
“One in 18 Americans lives in the LA Basin,” he said, “this makes our research extremely relevant.”

Pakbin and Sioutas believe that their findings will be relevant to other regions in the U.S. with air quality characteristics similar to the LA Basin.

Data from the study has already been shared with the Multi-Ethnic Study of Atherosclerosis (MESA) Air study, where associations between coarse PM and health will be assessed by expert epidemiologists.

The work was presented Monday at the 2010 AAAR conference and has been accepted for publication in the journal Aerosol Science and Technology.

For more information on Pakbin’s research, visit

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.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.