Air Pollution

Apr 7, 2010

Science Wednesday: OnAir: With Diabetes, Higher Air Pollution Risks

Air Pollution, diabetes, Science Wednesday 21 Comments

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

New studies by EPA grantees at Harvard suggest that exposure to air pollution makes the cardiovascular risks associated with diabetes even worse.

It’s well known that diabetes can cause an array of health problems and impose taxing lifestyle changes on those who suffer from it. But of all burdens associated with diabetes, heart disease may be the gravest.

Surfing some stats on the Center for Disease Control (CDC) website , I discovered that among diabetics, at least 65% of all deaths are attributable to heart disease—compared to just 27% in the population as a whole. What’s more, the American diabetes population is increasing at a very rapid pace (check out the maps I adapted from Maps of Trends in Diabetes.

Because of the heart-health risks to people with diabetes, EPA scientists suspected that air pollution, which also affects the cardiovascular system, may be particularly harmful to individuals with diabetes.

A new study has shown that, indeed, individuals with diabetes are twice as likely to be hospitalized for heart problems than those without diabetes. New EPA grantee studies show that respiratory and stroke deaths related air pollution are also twice as likely in people with diabetes.

So, why does this matter?

This new information is critical to the diabetes community and health professionals because it suggests that people with diabetes may need to pay extra attention to where they live and the air they breathe.

diabetes_1 The implication that people with diabetes could be more vulnerable to the effects of air pollution than the general population is a potentially crucial piece of information for air policymakers.

Under the Clean Air Act , the U.S. EPA is required to set air pollution standards to protect human health. Since there is a wide spectrum of vulnerability to the effects of air pollution, the EPA must design air standards to protect even the most susceptible populations.

As this preliminary research continues, policymakers will have a much better understanding of susceptibility in the growing population of Americans with diabetes.

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.

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Mar 26, 2010

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

AAAR, AAAR 2010 Specialty Conference, Air, Air Pollution, air quality, Science Wednesday 7 Comments

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.

Mar 24, 2010

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

AAAR 2010 Specialty Conference, Air Pollution, course particles, Science Wednesday 2 Comments

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.

Mar 23, 2010

OnAir@AAAR: Ironing out Trace Metal Measurements

AAAR, AAAR 2010 Speciality conference, Air Pollution, air pollution and health, Science Wednesday 2 Comments

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.

Mar 19, 2010

“OnAir@AAAR: Reporting on EPA Science from the 2010 Specialty Conference”

AAAR, AAAR 2010 Speciality conference, Air Pollution, Human Health 3 Comments

AAAR_intro Next week, I’ll have the exciting opportunity to spend time amongst the best and brightest air pollution scientists in the world at the 2010 AAAR “Air Pollution and Health” specialty conference in San Diego.

The conference is co-sponsored by EPA and this year the theme is “bridging the gap from sources to health outcomes”, a topic relevant to protecting human health both within the U.S. and abroad.

According to the conference website, I can expect to find “rigorous debates,” “state-of-the-art products” and “the latest information on linking adverse health effects of air pollution to emissions sources and atmospheric pollutants.”

During my 5 days navigating a sea of posters, talks, panels, and vendor fairs, I will plan to share daily photos and posts on the exciting EPA-relevant science I encounter. This is a unique opportunity to communicate up-to-the-minute information on science that is happening now.

Hot topics to look out for:

Cardiovascular disease, asthma, and diabetes as air pollution risk factors: What underlying health problems put you at higher risk?
Mortality and long-term particle exposure: Can pollution exposure lead to an earlier death?
Genetics and air pollution: Is our capacity to deal with air pollution written in our DNA?
Multi-pollutants: How can scientists study particle mixtures that contain hundreds of chemicals?
Atmospheric transport and transformation: What happens to pollutants once they are in the air?
Successes and challenges: Have actions to improve air quality been successful? Have there been unintended consequences?

Stay tuned…

About the Author: Becky Fried is a student contractor with EPA’s National Center for Environmental Research, part of the Office of Research and Development.

Feb 3, 2010

Science Wednesday: OnAir: Tunneling for Air Pollution Answers

Air, Air Pollution, emissions, Science Wednesday, tunnel for air pollution 7 Comments

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

Lately, John Godleski has spent a lot of time underground.

When I visited Harvard in December though, he surfaced for a chat with me about his unique research.

Along with colleagues at the Harvard Particulate Matter Research Center, Godleski has set up air pollution monitoring equipment inside a busy tunnel in the Northeast.

Part of the Toxicological Evaluation of Realistic Emission Source Aerosol, his study aims to assess differences between the health effects of exposure to particles directly from car exhaust (primary), and particles from exhaust that have transformed in the atmosphere (secondary).

The underlying hypothesis of the project is that breathing in particles that come directly from a vehicle might induce different health effects than breathing in particles that have spent time in the atmosphere, where they come into contact with sunlight.

To test the hypothesis, Godleski and his colleagues developed a photochemical aging chamber that essentially mimics real-world atmospheric conditions with simulated sunlight.

Exhaust from cars is fed into the chamber first with the artificial sun-lights switched to “off” and to then to “on.” This produces two types of output: exhaust with just primary particles (lights off), and exhaust with both primary and secondary particles (lights on).

Project scientists then conduct lab studies to look for differences in resulting health outcomes.

Preliminary findings suggest that the “lights on” particles, representing particles that have come into contact with sunlight, cause more lung inflammation and more potentially harmful oxidative activity in the body.

Since secondary particles in the air are ubiquitous, understanding their health impacts is extremely important.

“Though some people are involved in what directly comes out of a vehicle or a power plant, everybody is exposed to what happens to those particles once they are in the air,” Godleski explained.

Collection of exhaust particles directly from the tunnel makes this study especially representative of real-world particle exposure.

“If we go to a tunnel,” he continued, “we can get a mixture of vehicle output—we can get cars, we can get trucks, and we can get something very representative of what people ultimately may breathe. It gives us access to a mixed vehicle effluent in a way that nothing else does.”

This research is a critical step toward understanding the health effects of real-world airborne particle exposure. We will continue to report findings as Godleski continues to dig for answers.

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

Jan 13, 2010

Science Wednesday: OnAir: Breathe Cleaner, Live Longer

Air, Air Pollution, Clean Air, Science Wednesday, sustainability 9 Comments

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

On my second day of work, I was asked to find a Stephen Colbert video.

I found it on the Comedy Central web site

The subject of Colbert’s mockery is actually one of the most significant air studies recently published. It presents evidence, for the first time, that breathing cleaner air actually makes people live longer.

A 2009 study by Arden Pope, Majid Ezzati, and Doug Dockery published in the New England Journal of Medicine shows that cleaner air in the U.S. has increased life expectancy by an average of 5 months.

Over the past few decades, EPA has regulated air pollution because various scientific studies have determined that it is harmful to human health. As particles emitted into the air have been gradually reduced, pollutant levels in air have significantly decreased.

But despite the obviously cleaner air, it has been extremely difficult to confirm the resulting health improvements. Couldn’t better health also be attributed to decreased cigarette smoking, better eating habits and health care, or a variety of other changes?

Pope, Ezzati, and Dockery—an EPA PM Research Center grantee—matched air monitoring data with life expectancy data spanning three decades and 51 cities across the US. Using advanced statistical models, they accounted for any other factors that might also affect life span (like cigarette smoking) in order to see the effects of air quality alone.

Their results showed that an increase in life expectancy of 5 months was directly attributable to an average reduction of 6 micrograms per cubic meter of fine particle air pollution between 1980 and 2000.

The implication of the study—that EPA air regulations have directly and substantially lengthened human lives—is a triumph for both regulatory agencies and researchers world wide because it shows that air research and policy really do work.

Stephen Colbert isn’t the only one to recognize the importance of this finding. News of the study was reported in the Washington Post, New York Times, and in an entire segment on NBC Nightly News.

I spoke to Doug Dockery, investigator of the study and scientist at the Harvard School of Public Health, to get his take on the impact of this finding.

“There is an important positive message here,” he said.

“Efforts to reduce particulate air pollution concentrations in the United States over the past 20 years have led to substantial and measurable improvements in life expectancy.”

About the Author: Becky Fried is a student contractor with EPA’s National Center for Environmental Research, part of the Office of Research and Development.

Dec 30, 2009

Science Wednesday: OnAir – Cracking The Da Vinci Color Code

Air Pollution, Da Vinci, Personal Cascade Impactor Sampler, Science Wednesday, Southern California Particle Center 4 Comments

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

Constaninos Sioutas, Ph.D. typically conducts air pollution research on polluted highway roadsides or near running diesel engines. But a recent project lured him to a much more refined location— face to face with Leonardo da Vinci’s, The Last Supper.

Sioutas is a co-director of the Southern California Particle Center, a consortium of universities researching air pollution. The Center is funded by a multimillion-dollar EPA grant. Sioutas’ current research focuses on exposure to mobile air pollution sources and their potential toxicity, begging the question—what in the world does he have to do with da Vinci?

I got the chance to ask him in person when I traveled to his laboratory in October. As it turns out, over years of conducting air pollution research through EPA grants, Sioutas developed several new scientific instruments for capturing air particles and measuring their properties. One of these instruments, a Personal Cascade Impactor Sampler separates airborne particles by size and allows for analysis of the particles’ toxic content.

After developing this new technology, Sioutas started to think outside the box. What if this instrument could be used to understand how exposure to air and particle settling would affect the color longevity of a painting such as, say, The Last Supper?

image of DaVinci's Last Supper and Sioutas

Sioutas traveled to Milan to present a research proposal to The Last Supper’s curator, Dr. Alberto Artioli, asking just that question. He proposed to use his Impactor to take a series of measurements both inside and outside the legendary Refettorio, where the mural is on display.

Dr. Artioli was “positively impressed” and accepted Sioutas’ proposal. One goal of the project will be to determine the sources of particles settling on the painting, down to such diminutive possibilities as erosion from visitors’ shoes and clothing fibers, in addition to outdoor sources like traffic exhaust.

“It is really an amazing experience,” Sioutas said, beaming, “getting to apply these instruments for such a different task.” According to the project proposal, the study will draw conclusions about “the degradation risks to the Leonardo da Vinci’s painting.”

Read more about the EPA-funded research for developing the Personal Cascade Impactor Sampler at http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/5835

About the Author: Becky Fried is a student contractor with EPA’s National Center for Environmental Research, part of the Office of Research and Development. Her “OnAir” Science Wednesday posts chronicle EPA-funded research on clean air.

Dec 22, 2009

OnAir: Three Scientists Define One Elusive Phrase: “Oxidative Stress”

Air Pollution, oxidative stress, Science Wednesday, scientists 6 Comments

It has been long known that air pollution causes harmful health effects in people. But scientists have only recently begun to uncover some of the mechanisms behind this causal relationship, a necessary step in understanding how to best regulate air pollution and protect human health.

One key mechanism that EPA-funded research helped identify is oxidative stress. Though it is the subject of scores of scientific papers, finding a single, comprehensible definition of the term is a surprisingly arduous task.

During an October visit to the Southern California Particle Center, I asked three scientists to define oxidative stress in the context of air pollution. Here’s what they had to say:

Arthur Cho, PhD, Organic Chemist
“As the name implies, it stresses the cell and promotes the cell to secrete chemicals that stimulate an immune response, such as symptoms of asthma. The idea is that you’re exposed to air pollutants, the pollutants enter your lungs, components of the pollutants react with components in your lungs and these potentially harmful chemical reactions are initiated.”

Ralph Delfino, MD, PhD, Epidemiologist:
“It can be thought of as a biochemical imbalance in which large molecules are oxidized to the point where they become either toxic or, in the case of important biochemicals, dysfunctional. It induces a cascade of events that leads to inflammation and, at its worst, cell death. Inflammation, as seen in immune responses to bacteria or virus, can be a good thing. But there are types of inflammation, like arthritis for example, that are not good. Oxidative stress can lead to inflammation in lungs that worsens asthma, or inflammation in blood vessels that leads to atherosclerosis.”

Andre Nel, MD, PhD, Immunologist:
“The easiest way to describe oxidative stress is to give an analogy: If you bite an apple and you hold it up in the air it will go brown after a few minutes, same with a banana. What you observe there is decay in the fruits’ tissues because oxygen radicals in the air are attacking their cell membranes. The same principle applies in humans, where oxidative stress is damage to organs and cells by oxygen radicals we are exposed to.”

Next I’ll share some surprising research I encountered at the Southern California Particle Center and report from the second leg of my tour- Harvard.

Editor’s Note: Look for more of Becky’s “On Air” posts this Science Wednesday about other EPA-funded scientists she has recently met on her travels.

About the Author: Becky Fried is a student contractor with EPA’s National Center for Environmental Research, part of the Office of Research and Development.

Mar 18, 2009

Science Wednesday: China and Global Air Pollution

Air Pollution, China, Pollutants, Science Wednesday 5 Comments

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

About the author: Julie A. Layshock is a Ph.D. candidate in the Department of Environmental & Molecular Toxicology at Oregon State University. Her work is funded by an EPA Science to Achieve Results (EPA STAR) Graduate Research Fellowship. She is looking forward to a career focused on reducing human exposure to pollutants.

Westerly winds over the Pacific Ocean efficiently carry sea salt and dust from the Gobi Desert to the western United States. Recently, scientists have begun to detect other, less welcome, things in the wind, too: air particles laden with pollutants from fossil fuels.

People from countries around the world cause tons of pollutants to be emitted into the air we breathe. Everything from operating vehicles, to burning coal and natural gas for heat and electricity, and manufacturing and industry activities all contribute to the global transport of air pollution. The contribution this global transport makes to local air conditions is poorly understood, and the impact it makes to human health can not yet be estimated.

That’s where my research comes in.

image of author with clipboard I am working toward answering questions concerning long-distance air pollution and how China might contribute to pollution in the United States. In my travels to China, I have seen first-hand the effects air pollution can have on human health. Understandable questions arise: Can we really quantify the contribution of pollutants from China and determine the how they affect a person in the United States?

I spent several months in China collecting air particles that I can use to compare with ones I have collected in the Pacific Northwest. My goal is to identify specific pollutants arising from en route chemical reactions in the atmosphere. Using the chemical “signatures” of the particles, combined with powerful meteorological and wind mapping models, I aim to distinguish Chinese sources from our locally produced air pollution. In the laboratory, I am also designing toxicity tests using the collected particles and identifying the most toxic combustion byproducts.

The results of my research could provide much needed insight into the global movement of these combustion-derived pollutants that are attached to particles in the air.

Demonstrating that these pollutants are capable of traveling half-way around the world highlights the need to reduce this type of pollution. Alternative energies and creative pollution control techniques are just a few of the directions that could result from my research.

For further information, I can be reached at layshocj@onid.orst.edu.

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