BEINGS launches work on global consensus for ethical course of biotech

Novelist Margaret Atwood on stage at BEINGS with cognitive scientist Steven Pinker (center) and Thierry Magnin, who is a physicist, Catholic priest and professor of ethics.

By Carol Clark

Some of the world’s preeminent scientists and bioethicists gathered with leaders of philosophy, sociology, law, policy and religion in Atlanta May 18-20 for BEINGS 2015. The landmark summit launched work on a global consensus for the direction of biotechnology for the 21st century.

The setting for this futuristic event: The Tabernacle, an historic former church turned music venue, with red walls swirled with murals and wood floors that creak like the deck of a ship. Novelist Margaret Atwood, creator of fictional laboratory creatures such as the pigoon, gave a keynote.

“The lid is off the Pandora’s Box of genetic modification,” Atwood said. “This is a pivotal moment. Deliberate well. Keep the bar high. Take precautions.”

And with that, the tumultuous voyage began.

BEINGS, short for Biotech and the Ethical Imagination: A Global Summit, was organized by Paul Root Wolpe, director of the Emory Center for Ethics. “The idea is audacious,” Wolpe admitted of their plan to write global guidelines for the aspirations, ethics and policies of biotechnology within the next eight months.

Paul Root Wolpe on the potential and perils of biotechnology:


The BEINGS delegates are up to the task, he added. About 135 delegates from 25 countries joined the summit to take up the challenge of charting a course for how biotechnology can best contribute to human flourishing while navigating the potential perils and ethical pitfalls.

Tensions soon emerged as delegates from different perspectives took the microphone.

Harvard cognitive scientist Steven Pinker threw down the deregulatory gauntlet. “Stay out of the way” of biotech innovation, he urged, as scientists seek to prevent, treat and cure diseases. He cited major improvements in life expectancy around the world largely due to biomedical breakthroughs.

Pinker downplayed fears of eugenics and “designer” babies, while others countered that we are living in a world of competition and should be extremely concerned about the potential power to “edit” the genes of the human germline.

Princeton’s Ruha Benjamin, author of “People’s Science: Bodies and Rights on the Stem Cell Frontier,” called for the inclusion of those who identify as disabled in discussions about the goals and policies of biotechnology. “Anything less is presumptive and paternalistic,” she said.

It’s important to think about how to distribute benefits, added Benjamin, an assistant professor of African American Studies focused on issues of science and health. “There is no such thing as trickle-down biotech.”

Benjamin and three other delegates summarized their thoughts in an opinion piece for the Guardian: “As we pursue promising treatments, we should also be asking what we are trying to treat; whether it is best treated biomedically; who is included as funders, patients, donors and scientists; who is left out; who profits; and whether or not the treatment masks, depoliticizes, or exacerbates political and social inequality.”

By the afternoon of the first day of the summit, Wolpe said he knew the gathering was going to be a success. “I could tell by the tone of the conversation, and how people were lining up at the microphones to speak, that we had struck a chord,” he says. “We need to bridge a tension in philosophies, but both sides believe that curing human diseases and stopping suffering is an important goal. We have to get outside of the theoretical arguments and start talking about practical, specific issues.”

BEINGS divided discussions into the following major topic areas.

Aspirations and Goals: How should we think about differing goals of biotechnology, from making money, to curing disease, to understanding the basic nature of the organic world, to promoting human flourishing?

Alien Organisms and New (ID)entities: Cellular biotechnologies enable us to engineer novel organisms for industrial, environmental or therapeutic purposes. How might these organisms modify existing social systems and ecosystems, and how do we balance innovation with responsibility?

Bioterror/Bioerror: What are the potential dangers of synthetic biological materials and pathogens in terms of accidents or criminal intent?

Ownership: Should custom-designed genetic material or organisms be subject to patents and copyright?

Donorship: How can government and private sector entities collaborate to protect donors and create standards for bio- and stem-cell banks?

“All voices have a place,” Wolpe stressed. “We don’t have to agree on everything. Wherever we have honest, important disagreement in an area, we will note it in the final document.”

At the end of the summit, more than 80 delegates committed to actively working on writing the guidelines for the five major topic areas. Another 30 agreed to serve as reviewers and editors as drafts are ready. Their goal is to have a final document by next January, which they will submit for publication by a major journal.

“We do not represent just a single segment of society or government body or special interest,” Wolpe says. “We’re a group of global citizens who believe that for biotechnology to be used successfully it has to be used ethically. We as a group can create a document that is persuasive and has value.”

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WaterHub recycles wastewater to heat and cool buildings

Click here if video does not appear on screen.

Emory's WaterHub replicates the natural system of a wetland to recycle and treat sewer water so that it can be used to heat and cool the campus buildings. The facility is the first of its kind in the nation. You can take a tour of the facility this Friday, located behind the sorority houses on Eagle Row, as part of the grand opening of the WaterHub. Watch the video to learn more.

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Climate@Emory: Change is in the air

Steve Sclar, left, recently demonstrated on the Emory campus how he gathers indoor air quality data. (Emory Photo/Video)

By Carol Clark

Steve Sclar traveled to Golog Tibetan Autonomous Prefecture in China last summer to research the indoor air quality of nomads, who burn yak dung in their stoves for warmth and to cook their food. His measurements showed high levels of fine particulate matter in the smoked-filled tents and homes of some of the nomads. But Sclar also caught a glimpse of how global pollutants from industrialization may be impacting the isolated realm of the Tibetan plateau.

"The Tibetans are noticing changes in their climate and they're worried about the effects," says Sclar, an MPH student in Rollins School of Public Health's Department of Environmental Health. "Their grassland is getting poorer in the summer months and they see the snow pack getting smaller on the holiest mountain range in the region, known as Amnye Machen.

"I asked one nomad, 'What happens if Amnye Machen loses all of its snow?' He told me, 'Then it's the end of the world.'"

Climate change "is the biggest environmental health problem we face," Sclar says, "and yet it is so hard to pin down. There's no one country or entity to blame, and there is no one field of study that has the solution. We need to figure out how to reconcile all this."

Climate@Emory is an initiative made up of more than 50 faculty and staff from 20 departments across the university. Its goal is to harness Emory's strengths to help it play a leading role in the global response to perhaps the most complicated and pressing problem of our time. Since its launch last fall, the initiative has worked to support, connect and expand Emory's climate-related scholarship, teaching and community engagement.

"It's really not possible to understand climate change from the standpoint of any one discipline," says Eri Saikawa, who is Sclar's adviser and one of the founders of Climate@Emory. She is an assistant professor at Rollins and in the Department of Environmental Sciences. "We want to connect the dots to improve the quality and impact of Emory's research and provide a platform for intellectual engagement on climate change."

Read more in Emory Report.

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How zinnias shaped a budding biologist, and other fun facts about plants

"We're tied into plants in myriad and intricate ways," says biologist Roger Deal, who studies how plants build and adapt their bodies.

By Carol Clark

“I’ve always been really fascinated by plants, even from a young age,” says Emory biologist Roger Deal. “Their lives are so interesting, even though they are stuck where they are born.”

Deal's roots are in Columbia, South Carolina, where his father was a physician and his mother loved to garden.

“My first plants were zinnias,” he recalls. “I was about 10 and my mom and I went to the garden store where I picked out a packet of seeds. You have these little dry things that look like pieces of dust. All you have to do is put them in the ground and get them wet, and then you have a whole organism. I thought, ‘Wow, what an amazing life cycle! How does it work?’”

Roger Deal

Plants go back millions of years, when the Earth’s atmosphere contained very little oxygen. “Where did all that extra oxygen come from? It’s a byproduct of plants,” Deal says. “All the energy that we need to live also comes from plants. And they’re beautiful – they’re an important part of our aesthetic. We are basically tied into plants in myriad and intricate ways.”

As an undergraduate at the University of South Carolina, Deal worked in a lab that studied phytoremediation, or the process of using plants to clean up pollution. “A lot of plants are tolerant of heavy metals,” he explains. “I worked on a project that was exploring how to use Spartina, the grass you see growing along salt marshes on the coast, to suck mercury pollution up out of the soil.”

Deal became interested in how genes are controlled in plant development during his graduate school years at the University of Georgia.

In his lab at Emory, he’s continuing this focus on how plants build and adapt their bodies. By digging deep into the developmental biology and genetics of plant systems, he hopes to unearth secrets that could benefit both agriculture and human health.

“A big question in studying the genome of any organism is figuring out where all the genes are, and how you put all the parts together to build an organism,” he explains. “Humans have a parts list of about 30,000 different genes, for example, but only 2 percent of our genome is genes. The rest was once considered junk DNA, but we now know that it’s not junk.”

Watch a video of Roger Deal:


DNA is not just floating around by itself in the nucleus of a cell. It’s wrapped up in little globules of proteins called histones. By wrapping tightly around histones, a six-meter long strand of DNA can cram into a cell nucleus.

“This complex of histones and DNA is called chromatin,” Deal says. “The chromatin is used to turn genes on or off, which determines the function of a cell. So chromatin is part of the system that differentiates the cells when an embryo is growing. Chromatin is also involved in establishing and maintaining cell proliferation. If cell proliferation gets turned on inappropriately, the result can become a tumor.”

One of the model organisms Deal’s lab uses is Arabidopsis thaliana, a small flowering plant that is a member of the mustard family. “It’s just a lowly little weed that you’ve probably stepped on and not noticed,” Deal says of Arabidopsis. “It grows all over the northern hemisphere.”

The Arabidopsis genome is about one-twentieth the size of the human genome. “It’s sort of streamlined,” Deal says. “It has about the same number of genes as we do, but it has way less ‘intergenic’ DNA. So in terms of finding the regulatory parts, we have a lot less stuff to look at. When it comes to lab research, Arabidopsis is like the fruit fly of the plant world.”

Arabidopsis thaliana (NIH)

Arabidopsis plants begin their life as the fusion of a sperm and an egg: A single cell, which develops into an embryo inside of a seed. “This little embryo can sit there for decades,” Deal says. “But once it gets wet, the whole thing kicks into action. Suddenly, it starts growing, pops a root, develops leaves.”

At some point, the plant switches from vegetative growth to reproductive growth. “Something in the environment, the length of the day, the quality of light, tells these plants it’s time to stop making leaves and start making flowers,” Deal says. “A really important question is how this switch operates at the molecular level.”

A key part of the puzzle appears to be a histone protein called H2AZ, which is an important component of chromatin in plants, animals and fungi.

“The H2AZ gene is essential for life in animals,” Deal says. “If an embryo doesn’t have it, the embryo stops developing and dies. But an overproduction of an H2AZ molecule appears to drive the genesis of several types of cancer, including breast and prostate cancer.”

Plants, unlike laboratory rats, can survive without the H2AZ gene. “If you knock out the H2AZ gene in Arabidopsis plants they don’t die, it just messes them up,” Deal says. “The lack of H2AZ affects the leaf size, flowering time and their susceptibility to pathogens and other stresses.”

That makes Arabidopsis an easily accessible model to study this particular gene and its on-and-off switch. “We can mess with Arabidopsis in pretty extreme ways, removing this critical regulator of a process, and then study what happens at the molecular level,” Deal says. “We’re hoping that our research will help us understand something about the biology of cancer and the biology of animal and plant development all in one fell swoop.”

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Atlanta Science Festival offers formula for fun

Emory chemist Doug Mulford gets kids fired up for science during a demonstration at last year's Atlanta Science Festival. Emory Photo/Video

By Carol Clark

Start with a beaker as big as metro Atlanta. Add scientists, artists, music, dance, robots, games, movies, lab tours and chances to try new technology and conduct fun experiments. Throw in some liquid nitrogen ice cream, giant soap bubbles and Tibetan momos. Now mix with hundreds of enthusiastic volunteers and thousands of curious people of all ages. Finally, jump in yourself.

The Atlanta Science Festival is back, March 21-28, with its ever-evolving formula for fascination and fun. The eight-day celebration of local science and technology encompasses more than 120 events at 70 venues throughout Atlanta, including many on the Emory campus. The festival culminates in the Exploration Expo at Centennial Park on Saturday, March 28.

“We want to help our community become proud of the resources, research and discoveries happening here, and all the opportunities for careers,” says Jordan Rose, co-director of the festival and associate director of the Emory College Center for Science Education. “The more we can connect people to local scientists and their innovations, the more people can get excited about science in general.”

Last year, 30,000 people attended the week-long inaugural Atlanta Science Festival, including 16,000 who came to the Exploration Expo, which was chaired by Emory chemist Monya Ruffin. "It’s hard to predict attendance this year for all of the events over eight days, but we’re expecting at least 20,000 people for the Expo alone,” Rose says. “It’s going to be a busy day at the park.”

About 20 booths at the Expo will feature Emory science faculty and students. ChEmory, for example — the outreach group made up of Emory chemistry undergraduates — will return with its popular dance pit. Kids can kick their shoes off and experience moving to music through a non-Newtonian fluid.

Several events are scheduled on the Emory campus on Saturday, March 21, targeting both adults and children. You can find details about all the Emory events here.

Read more in Emory Report.

Fossil tracks mark student's passage into New World of discovery

“Wherever you go, you should always pay close attention to your environment because you never know when you could come across something really cool," says Emory graduate Meredith Whitten, shown basking in the winter sun of the Bahamas.

By Carol Clark

Nobody knew better than Christopher Columbus that knowledge and experience, guided by luck and the right conditions, are key to making a discovery – even an accidental one. On October 12, 1492, he found what he thought was a shore of the Indies, but was actually an island in the Bahamas that he christened San Salvador.

During the winter break of 2013, Emory senior Meredith Whitten was on San Salvador for a study abroad trip, part of an environmental sciences class called “Modern and Ancient Tropical Environments.” Whitten had already visited the island when she took the course as a sophomore, and she was returning as a teaching assistant.

“It’s a great course because you get to go back into the past by looking at the rocks,” Whitten says. “It’s cool to see how the Earth has changed and also stayed the same.”

“She brought a lot of knowledge and experience to the group,” adds Anthony Martin, the professor who developed and teaches the course. Martin is a paleontologist who specializes in trace fossils: Tracks, burrows and other signs of ancient life.

“We go around the entire island in a big, open-bed truck,” Martin says of the field portion of the class. “We stop at known fossil sites, and at interesting modern environments to imagine what they might have looked like in prehistoric times. I call it ‘The Magical Mystery Tour.’”

Whitten stands by the fossil track site, the pale patch of rock next to her feet.

On December 30 of 2013, that tour stopped at a shoreline site where Martin noticed an outcrop of red rock. “I wanted to explain to the students about palesols,” Martin says. That paleosol, or fossilized soil, originated as dust from the Sahara desert. Not unlike Columbus, that dust was carried across the Atlantic by trade winds and deposited on San Salvador. “Some of that dust had iron minerals that got oxidized and, like the red socks in your wash, colored the sediment,” Martin says.

While he was explaining all this to the students, Whitten was looking at a patch of white rock being lapped by the ocean. “I could tell that the rock was recently exposed because it was so white and hadn’t been weathered,” Whitten says. “There must have been some storm surge that had recently broken off the top layer.”

A wave had just splashed the rock, darkening its features. And it was late afternoon, so the light slanted at just the right angle to make details in the rock’s surface pop out. Still, only someone who knew what to look for could have noticed the faint impressions.

“I saw the shapes and called Dr. Martin to come over, I thought I’d found fossilized bird tracks,” Whitten recalls. “I was sort of surprised when he looked at them and agreed. It was very cool and exciting for both of us.”

It took knowledge, experience and a careful eye to spot the faint impression of a partial bird track.

The field class turned into a real-life lesson in how to document a fossil find.

Whitten and Martin are co-authors of a paper on the two partial bird tracks, to be published in March by the journal Geologica Acta. The avian footprints are the first known vertebrate trace fossils on San Salvador, and only the second example from the Bahamas. They date back about 120,000 years, to the Pleistocene Epoch, and match the size and form of tracks made by modern-day gulls.

“Fossilized tracks like these give us a better idea of what previous environments were like,” Whitten explains. She notes that it’s likely shorebirds were walking around the upper part of a beach, near the dunes, when the tracks got cemented in carbonate sand, buried and preserved. “Understanding past coastal environments, and how sea levels have changed, could give us insights into what may be occurring as we look ahead at climate change.”

After graduating from Emory last May, Whitten decided to take time off as a dive instructor in the Bahamas before entering graduate school with the aim of a career in managing fishery policy.

“It was so fun to have a day in the field turn into so much more,” Whitten says of her experience in the Emory class. “Wherever you go, you should always pay close attention to your environment because you never know when you could come across something really cool.”

Columbus couldn’t have said it better.


Photos courtesy Meredith Whitten

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The search for alternative chemistries of life heats up

Research into alternative chemistries of life has implications for everything from the health of humans to the health of Earth’s ecosystems. (NASA photo)

By Carol Clark

Ideas about directing evolution of life forms on Earth and finding life on other planets are rapidly morphing from science-fiction fantasy into mainstream science, says David Lynn, a chemist at Emory University.

“These areas of science are rapidly coming of age because of our increasing knowledge and advancing technology. It’s an exciting time. We’re on the threshold of answering fundamental questions including: What is life? Are there forms of life that we haven’t even yet imagined? Are we alone in the universe?”

A panel discussion, “Searching for Alternative Chemistries of Life on Earth and Throughout the Universe,” is set for Friday, February 13, at 3 pm, during the annual meeting of the American Association for the Advancement of Science (AAAS) in San Jose. Lynn co-organized the panel with Jay Goodwin, an Emory research fellow and an AAAS Science and Technology Policy Fellow.

In 2012, Lynn, Goodwin and four other scholars led the “Workshop on Alternative Chemistries of Life: Empirical Approaches,” supported by the National Science Foundation and the National Aeronautics and Space Administration. They pulled together an international group of nearly 40 scientists working at the boundary of non-living and living systems for the Washington workshop. The group included microbiologists, marine biologists, biochemists, geochemists, synthetic chemists, atmospheric chemists, and virologists.

The resulting report, now available online, developed a set of research findings and next steps for exploring the concept of alternative chemistries.

The AAAS panel session will discuss many of the main ideas outlined in the workshop report, and the key question: How do we unravel the complex interplay of planetary, chemical and biological evolutionary networks, and what might we gain from the confluence?

“We’re at a critical point where we need to mobilize resources and bring together different research realms and take a holistic approach to this question,” Lynn says. Such research could have implications for everything from the health of humans to the health of Earth’s ecosystems as the planet undergoes climate change and a sixth mass extinction of life’s diversity, he adds.

Lynn is one of four speakers set for the AAAS panel. He will discuss his own research, which involves a bottom-up approach to exploring how organisms evolved from non-living to living systems.

Caltech geo-biologist Victoria Orphan will discuss taking a top-down approach to studying alternative chemistries of life by tracing the biological diversity back through time to its origins.

Biochemist John Chaput, from Arizona State University, will talk about his work at the interface of research into alternative chemistries of life, where the bottom-up and top-down approaches meet.

Astrophysicist Carolyn Porco, from the Space Science Institute, will discuss efforts underway to answer one of the most beguiling questions facing humankind: Is there life beyond Earth?

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In the Balkans, resilience is rooted in knowledge of wild plants

The unripe fruit of Prunus domestica, in the rose family, is a favorite snack for Gorani children.

By Carol Clark

Traditional communities living in isolated, rural areas with little money or infrastructure tend to have one thing in common: Resilience rooted in intricate knowledge of their natural environment, especially plants.

This knowledge may be relevant to some of the biggest problems in plant science, including climate change, conservation biology, food security and human health, says Cassandra Quave, an ethnobotanist at Emory University.

Quave led an ethnobotanical study centered on a remote corner of the Balkans that was published in the journal Nature Plants. Her co-author is Andrea Pieroni from the University of Gastronomic Sciences in Pollenzo, Italy.

“Ethnobotany is the study of the interactions of people and plants,” Quave says, “but it has also been described as ‘the science of survival.’ People’s knowledge of which plants are beneficial, and how to harvest and preserve those plants, can make a huge difference in the overall well-being of a community.”

An Albanian describes plant uses.

Emory’s Center for the Study of Human Health funded the study, with additional support from the University of Gastronomic Sciences.

The study compared how two different cultures used plants in the Gora region of northwestern Albania, near the border with Kosovo. The researchers focused on a rural district of Gora that is one of the most economically disadvantaged in Albania. The two cultures in the study, Albanians and the Gorani ethnic minority, were both Muslim and subsisted primarily on small-scale agricultural, especially potato farming. The area is mountainous and many “roads” are unpaved, rocky paths. Some communities can be cut off completely from the outside world by heavy snows during the long winters.

“This area was heavily affected by the Balkan conflict of the 1990s,” Quave says. “The adults there have living memories of extremely challenging times. Even in peace time, life is difficult.”

The researchers conducted interviews with more than 100 residents about 104 different species of plants in their local environment. They recorded 418 uses of these plants for a broad spectrum of food, health, ritual and economic purposes.

The plant uses of the two cultures tended to overlap when it came to food, the study showed. Stinging nettle, for example, is a dietary staple among both the Albanians in the study and the Gorvani. “They boil nettle and use it the way we would spinach,” Quave says, sometimes mixing it with cheese, and baking it into local pastries known as byrek or pita.

A willow tree next to a Gorani home.

The researchers also found 77 divergent uses for plants between the two cultures, including 43 plant species. “Culture affects the way people view the natural environment,” Quave says. “And those views can affect everything from home healthcare practices to diet and local economies and conservation issues.”

The Albanians in the study, for example, reported less of an affiliation with a species of willow tree known as Salix alba, while the Gorani often choose to plant this tree around their homes and have many uses for it. “It’s what we call a cultural keystone species because it is so entwined with their way of life,” Quave says.

When a Gorani man wants to propose marriage to a woman, he may dig up a willow sapling and place it by her front door. If the woman accepts the proposal, the family plants the sapling in their field. If she rejects the suitor, the sapling becomes firewood.

Both the Gorani and Albanians use willow branches with leaves as protective amulets over their doors. And they add willow leaves to the fodder of their livestock once a year, along with some other plants, because they believe it helps keep the animals safe and healthy, Quave says.

Another example of a tradition used primarily by the Gorani involves the use of the plant Nepeta cataria, commonly known as catnip, to treat fright. “If a child has a nightmare,” Quave says, “they might brew a cup of catnip tea to soothe them.”

To store up supplies for winter months, both the Albanians and Gorani in the study use lactic fermentation to preserve food. If they need starter culture for fermentation, they use the roots from certain plants.

“They have a great deal of knowledge about their local environment that has been handed down to them through generations,” Quave says. It’s important to record that knowledge, she says, both because it could have possible relevance for science and because it could help communities improve their well-being.

“A lot of international attention has been focused on the Balkans to try to support reconciliation and development,” she says. “If you really want to help local communities in a way that’s sustainable and culturally sensitive, it’s important to have a detailed understanding of how they interact with their environment.”

Photos courtesy of Cassandra Quave

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Tapping nature to clean wastewater

In the WaterHub's 2,200-square-foot greenhouse, campus wasterwater is filtered and circulated among plant roots, where microbes naturally consume organic material.

By Kimber Williams, Emory Report

A new Emory facility, called the WaterHub, uses adaptive ecological technology to naturally break down organic matter in wastewater. The WaterHub is projected to help Emory reclaim some 300,000 gallons of campus wastewater daily, cutting potable water consumption as much as 35 percent and saving the university millions in water utility costs over a 20-year period, according to Matthew Early, vice president for Campus Services.

"Emory is a leader in sustainability," Early says. "With this facility, we’re taking a major step forward in becoming one of the first in the nation with this technology for cleaning our own wastewater."

Even as the facility was being constructed last semester, it was being put into service — Emory students used it for research by monitoring the changing microbiology of wastewater samples as the new project was ramping up.

Read more about the WaterHub.

Yak dung burning pollutes indoor air of Tibetan households

A child sits before the family stove, fueled by yak dung, in a traditional tent in Tibet. (Photo by Qingyang Xiao.)

By Carol Clark

Tibet, the highest region on Earth and one of the most remote, is associated with vivid blue skies and the crystal clear air of the Himalayas. During the long cold season, however, the traditional nomadic people spend much of their time in snug dwellings where they cook and stay warm by burning yak dung. Their indoor air can be filled with dangerous levels of fine particulate matter, including black carbon, a new study finds.

The journal Atmospheric Environment published the research, led by Eri Saikawa, an assistant professor of in Emory's Department of Environmental Sciences and in the Department of Environmental Health at the Rollins School of Public Health.

“Indoor air pollution is a huge human health problem throughout the developing world,” Saikawa says. “In a cold region like Tibet, the impact on individuals could be even greater because they spend so much time indoors and try to keep their homes as air tight as possible.”

Globally, the World Health Organization (WHO) estimated that 4.3 million people died prematurely in 2012 due to indoor air pollution from traditional stoves, fueled by coal, wood, dung or crop waste. In comparison, WHO estimated that outdoor air pollution was linked to 3.7 million deaths that year.

Yaks are an integral part of the Tibetan way of life. (Photo by Denise Jarvis/Wikipedia.)

Tibet is situated on a plateau northeast of the Himalayas in China. For centuries, nomadic people there have herded yaks, large, long-haired relatives of cattle. Yaks work as pack animals and supply meat, milk, and fiber for fabrics. They also generate heating fuel in the form of dung.

Previous studies had looked at indoor air quality in Tibet during the summer season. Saikawa and her team wanted to investigate indoor emissions during the colder months.

In March of 2013, Qingyang Xiao, a graduate student in Rollins School of Public Health, traveled to the Tibetan region of Nam Co (which means “heavenly lake”) to gather the data. About 4,500 residents live in the region, at an altitude of 4,730 meters.

Xiao used battery powered aerosol monitors to measure indoor concentrations of fine particulate matter, or particles 2.5 micrometers in diameter or smaller, which consists mainly of black carbon and organic carbon. She recorded the measurements in six households with different living conditions and stove types. Yak dung was the main fuel for cooking and the only fuel for heating.

The results showed that the average concentrations for black carbon and fine particulate matter were nearly double those reported by some similar studies of households in areas of lower altitude and warmer climates, such as India and Mexico.

Most of the families surveyed said they were aware of the dangers of indoor air pollution. (Photo by Qingyang Xiao.)

The Tibetan homes included four traditional tents and two simple stone houses. Both the tents and the houses had only one room where all of the family members slept, ate and cooked.

Three of the families used traditional open stoves without chimneys, and three had added chimneys to their stoves. A simple house with a chimney had the lowest indoor concentrations. This household lived on tourism and used liquefied petroleum gas (LPG) for cooking.

However, a stone house with a chimney had the highest black carbon concentrations.

“That was surprising,” Saikawa says. “It shows that it is misleading to think that having a chimney will always improve the situation, unless you can be sure that the home is ventilated correctly and that you have proper air flow within a dwelling.”

Xiao also surveyed members of 23 households on energy use and awareness of indoor air pollution. The families said they spent an average of 16 hours a day indoors during the colder months of the year. 

Seventy percent of those surveyed said that they were aware of the health problems associated with indoor air pollution, and some of them did not have the economic means to purchase a chimney. (The average annual income per household is less than $900 a year, and a chimney costs around $60.)

The moisture content of the yak dung is another key factor in the emission levels, Saikawa says. After a rain or snowfall, the piles of uncovered dung are moist, leading to incomplete combustion and more emissions of fine particulate matter due to increased organic carbon by smoldering.

“It’s a complicated issue,” Saikawa says. “It’s much more than just a science problem. You have to understand how people live if you want to help find solutions to improve their lives.”

The Emory research team, including students from environmental sciences and the Rollins School of Public Health, is expanding on the small sample of households in this initial study. They are investigating indoor emissions in other areas of Tibet and plan to link these measurements to a biomarker study based on blood samples of people living in the households.

Saikawa, a specialist in atmospheric chemistry, is also studying levels of black carbon emissions in the outdoor environment generated by the burning of biomass fuels like yak dung.

Black carbon absorbs heat in the atmosphere and reduces the ability to reflect sunlight when deposited on snow and ice. Its impact is greatest at high altitudes. “Black carbon emissions from burning biofuel such as yak dung have not been quantified before in the atmosphere of the Himalayas,” Saikawa says. “We know that many Himalayan glaciers are melting rapidly, and our work suggests that more black carbon is getting deposited on them than previously thought.”

She hopes to eventually work with Georgia Tech engineer Jonathan Colton to develop gasifier cook stoves that would burn yak dung in a more efficient matter, producing fewer emissions. The stove would need to be portable, to suit the nomadic way of life, affordable for the Tibetans and simple to maintain.

“We want to use our data to make the world a better place,” Saikawa says. “The ultimate goal is to reduce pollution from biomass fuels in ways that benefit human health and reduce the climate impact.”

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Climate change will slow China's reduction in infectious diseases

Shanghai depends on water from the Huangpu River, which is connected to the heavily polluted Tai Lake. Photo by Jakub Halun.

From Woodruff Health Sciences Center

China has made significant progress increasing access to tap water and sanitation services, and has sharply reduced the burden of waterborne and water-related infectious diseases over the past two decades. Climate change, however will blunt China’s efforts at further reducing these diseases, finds a study in the latest edition of Nature Climate Change.

By 2030, changes to the global climate could delay China’s progress reducing diarrheal and vector-borne diseases by up to seven years, the study shows. That is, even as China continues to invest in water and sanitation infrastructure, and experience rapid urbanization and social development, the benefits of these advances will be slowed in the presence of climate change.

The study, led by Justin Remais, associate professor of environmental health at Emory’s Rollins School of Public Health, provides the first estimates of the burden of disease due to unsafe water, sanitation and hygiene in a rapidly developing society that is subjected to a changing climate.

“Our results demonstrate how climate change can lead to a significant health burden, even in settings where the total burden of disease is falling owing to social and economic development,” says Remais. “Delays in development are especially concerning for China, which is investing heavily in improving health even as the impact of those investments is being countered by the effect of climate change.” 

Read more.

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Interstellar: Starting over on a new 'Earth'

The movie Interstellar opens in theaters at a time when Earth is facing major losses of biodiversity and ecosystems, says David Lynn, an Emory professor of biomolecular chemistry.

While humanity is challenged to find out what’s happening to Earth and how to make adjustments, we have also begun to realize that billions of Earth-like planets likely exist in habitable zones around the stars of our galaxy.

“In as little as 10 years, we could know whether we’re alone in the universe, whether there are other living systems,” Lynn says. “That’s an exciting prospect. It’s not clear necessarily that we’ll find out that there is intelligent life or not. That may be a lower probability, but that’s also possible.”

Much of the science in Interstellar is not accurate, and its vision of the future may not come true. And yet, it is still an important film, Lynn says, since its themes resonate today, during a critical time in our history.

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Ebola's backstory: How germs jump species

Fruit bats are associated with an array of deadly viruses, including Nipah, Ebola and Marburg. As the bats' habitat shrinks, the odds increase that bats will cross paths with humans, wild primates and other animals.

By Carol Clark
From Emory Medicine

While virologists study pathogens like Ebola by zooming in on them with an electron microscope, primate disease ecologist Thomas Gillespie climbs 100-foot trees in the tropical forests of Africa to get the big picture view. He tracks pathogens in the wild to learn how they adapt to changing environments and jump between species.

It is physically challenging work that often takes him into remote forests where the wildlife has not yet learned to fear people. A chimpanzee turned Gillespie into a human yo-yo while he was ascending a tree with a rope and harness. “Chimpanzees have 10 times the strength of a man and they can be curious and playful,” he says. “I once had an adult male chimpanzee grab my rope and bounce me up and down.”

Wild primates pose a special risk for zoonotic diseases—those transmissible from animals to humans—due to our close genetic relationship. HIV/AIDS and Ebola are the two most dramatic examples of diseases linked to wild primates, but many other viral, bacterial, fungal, and parasitic pathogens found in apes and monkeys are readily passed to humans.

“The bottom line is that the majority of emerging infectious diseases are coming from wildlife and most of that wildlife is in tropical forests,” says Gillespie, a professor in Emory’s Department of Environmental Sciences and the Rollins School of Public Health. “We can’t afford to just focus on one pathogen or one animal. It’s really important to get a general understanding of the interactions of different species, and how changes in the environment are driving zoonotic disease transmission.”



Gillespie is investigating undisturbed forests, as well as sites where logging and other human activity is under way. He gathers fecal and blood samples from people and animals for analysis while also scouring the forest floor and treetops to learn about the diversity of pathogens in the environment. The data can then be mapped spatially and over time to connect the dots of disease ecology.

For one ongoing study in Uganda, Gillespie and his collaborators are following primates in and around fig trees. The researchers hang out near these ancient forest giants, observing the tableau of life feeding amid the branches and on the ground below.

Fig trees are a keystone species of rainforest ecosystems. Climate change is playing havoc with the seasonal fruiting of other types of trees. But fig trees have co-evolved with specific pollinators—fig wasps—and due to their complex interaction, there is always a fig tree fruiting somewhere in the forest, providing a critical, consistent food source for fruit bats, primates, and ground dwellers like the bush duiker, a shy, dainty antelope that darts amid the forest shrubbery.

Fruit bats, associated with an array of deadly viruses including Nipah, Ebola, and Marburg, are especially specific in their diet. “They’re looking for ripe fruit,” Gillespie says, “and that’s a rare resource in the environment.”

And it’s becoming even rarer. Logging companies are cutting down huge swaths of African forests. Mining operations are moving into new terrain. Villages are expanding, and homes and food crops are eating into the wilderness. All these factors bump up the odds that fruit bats will be living near people, and that the bats will be joined by a variety of other animals while they are feeding from a tree.

“Most viruses can only last outside of a host for minutes or hours, not days,” Gillespie says, “but now we have this changing landscape of food availability. That raises the probability that a gorilla or chimpanzee will eat a piece of fruit that a bat has just defecated on, or has bitten into and discarded.”

Diseases and parasites could be transmitted in this manner. Ebola is one of the rare ones, extremely difficult to find, much less study, in the wild. But Ebola looms large in the public imagination because it is hemorrhagic, capable of causing massive bleeding, and because of its high fatality rate. It is also frightening because it is so mysterious, popping up out of the forest to kill voraciously then disappearing again for years.

The virus was first identified in 1976, following an outbreak in a remote hamlet of Zaire (now the Republic of Congo) near the Ebola River. Subsequent outbreaks have also been associated with forested backwaters and have quickly burned themselves out. That is, until the current outbreak in West Africa. Ebola has now made the leap from rural, forested regions to Africa’s urban areas, where many people live in crowded conditions with poor sanitation.

One of the biggest mysteries is where the virus has hidden between these outbreaks. Evidence of Ebola antibodies, and remnants of Ebola RNA, have been found in the blood of three species of fruit bats, making them prime suspects as an Ebola reservoir: An organism that can carry the pathogen without dying or even becoming sickened by it.

“Fruit bats are the best guess as to the reservoir, but until a live virus is found in their blood, we cannot be sure,” Gillespie says. “What we do know is that bats are an important part of the equation. And gorillas, chimpanzees, and some other animals, like the bush duiker, can get infected with Ebola.”

During the past decade, human Ebola outbreaks in Gabon and Congo have been accompanied by reports of gorilla and chimpanzee carcasses in surrounding forests, and epidemiological studies have connected encounters with dead gorillas, chimpanzees, and bush duikers to human cases.

“A hunter might find a dead gorilla in the forest,” Gillespie says, “and instead of saying, ‘I shouldn’t butcher this animal and eat it, it may have died of an infectious disease,’ he throws up his hands and says, ‘Thank you, God, for this gift!’ ”

Fruit bats are also hunted for food in many parts of Africa.

But you don’t have to be a hunter going deep into a forest to catch Ebola. Now that fruit bats are feeling the squeeze of fewer food sources, they may choose to roost under the eaves of a home, feasting on trees in the village orchard as children play below.

Widespread education about what is safe to eat and what is not, and how to identify animals that may have died from an illness, is becoming a vital part of preventing the spread of these diseases.

Just as people are encroaching on wilderness, pathogens are expanding their range into human habitats.

“We’re changing the environment in ways that may be promoting Ebola,” Gillespie says. “As the human population grows and the demand for resources pushes us into new areas, we’re going to see more diseases emerge. Anytime we alter a pristine natural system there are going to be unintended consequences.”

Photos: Thinkstock

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The physics of falling icebergs

By Carol Clark

For thousands of years, the massive glaciers of Earth’s polar regions have remained relatively stable, the ice locked into mountainous shapes that ebbed in warmer months but gained back their bulk in winter. In recent decades, however, warmer temperatures have started rapidly thawing these frozen giants. It’s becoming more common for sheets of ice, one kilometer tall, to shift, crack and tumble into the sea, splitting from their mother glaciers in an explosive process known as calving.

“Imagine a sheer, vertical ice face three times as tall as the tallest building in Atlanta breaking off from a glacier and flipping 90 degrees,” says Emory physicist Justin Burton. “In my lab, we can calculate how much energy is released during one of these events, which can be equivalent to several nuclear bombs.”

Burton studies the geophysics of calving icebergs in order to better understand and predict effects of climate change, such as sea-level rise.

“Ice coverage is one of the most sensitive indicators of climate change,” he says. About half of the loss of ice from the polar ice sheets is occurring due to melting and half due to iceberg calving. While it’s more straightforward to estimate iceberg melt rates, their calving rates are much harder to pin down.

Greenland's Ilulissat fjord is believed to have spawned the iceberg that brought down the Titanic.

For the 2012 film “Chasing Ice,” videographers endured subzero temperatures and years of patience to record stunning time-lapse footage of ancient glaciers receding. Their efforts also yielded the largest calving event ever captured on film. The area involved was about the size of Manhattan. The filmmakers described it as like watching skyscrapers rolling around in an earthquake and an entire city breaking apart before their eyes.

Direct field observations of calving icebergs are as dangerous as they are rare. So Burton and his colleagues developed ways to model these events in a controlled, laboratory setting. “We can measure things that can’t be measured in the field,” he explains, “and it’s also way cheaper and safer.”

He and his colleagues built a cylindrical, Plexiglas water tank as a scaled-down version of a fjord, similar to the ice-walled channel at the end of the Ilulissat glacier, which drains the Greenland ice sheet into the ocean. This well-studied glacier, also known as Jakobshavn, is considered an important bellwether for climate change.

While it is normal for glaciers to both accumulate and shed ice, Jakobshavn provides a vivid snapshot of how the shedding process has speeded up. The glacier retreated 8 miles during the 100-year period between 1902 and 2001, but has retreated more than 10 miles during the past decade. Greenland’s ice sheet appears to be out of balance, losing more ice than it gains.



Burton’s lab creates experimental models to gain a more precise understanding of these glacial processes. Rectangular plastic blocks that have the same density as icebergs are tipped in the water tank and the resulting hydrodynamics are recorded.

One hypothesis that the lab is investigating is how the waves unleashed by capsizing icebergs may be causing earthquakes that can be detected thousands of miles away. “It’s counterintuitive,” Burton says, “because usually you think of earthquakes as causing large waves and not the other way around.”

The lab models, however, suggest that the violent rotation of massive icebergs generates waves that release the brunt of their energy onto the sheer vertical face of the glacier, instead of dispersing most of it into the ocean.

“If we can correlate the frequencies of earthquake signals with the frequencies of icebergs rocking back and forth in the water, then that could be a direct measurement of the size of the icebergs that have broken off,” Burton explains. “Large iceberg calving events could then be detected and measured using remote seismic monitoring.”

Climate change and its impacts is one of the top problems in science, Burton says. “We’re seeing huge changes occurring within a few years and we’ve got to get on it. I’d like to think that, a few decades from now, we were able to do something.”

Photo of Ilulissat by iStockphoto.com

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Written in poo: The story of prehistoric life

The mighty T-rex may be long gone, but descendents of its lowly pooper-scooper, the dung beetle, are alive and well and still telling tales.

By Eddy Von Mueller, Emory Magazine

An iridescent beetle, bright as a bead, has caught a whiff of paradise. She makes a beeline for a pile of fresh manure, high as a hill to her, recently left behind by 
a Maiasaurus striding through the rookery on some motherly errand.

It’s a noisy place, this. The herd is a big one, and there are hundreds of nests here. Adult animals rumble, or possibly honk or hiss as they jostle each other. Some of the nests are already full of broken eggshells and little Maiasaurs bawling to be fed.

The beetle takes no more notice of the clamoring dinosaurs than they do of her. She has family matters of her own to attend to. She’s a dung beetle, and, the risk of getting stepped on notwithstanding, hanging around a bunch of nine-meter-long herbivores the size of SUVs means living very large. She burrows eagerly into the heap.

Later, burrows and their chiropteran hardihood will help her million-times-great-grandchildren survive the asteroid impact that will doom Maiasaura and most of her kind 
to extinction.

Later, her descendants will be digging 
into the dung of proto-elephants on the savannahs where an ape will stand, starting no end of trouble.

Later, pyramids will rise, and the civilization that erects them will fall, having ironically put the humble dung beetle, the scarab, at the very center of their cosmology.

For now, a “now” seventy-five million years ago, this beetle will lay her eggs inside the tunnel she’s made, and seal it snugly behind her when she leaves, ensuring that the larva will 
be secure in a chamber literally made of food. “It’s dinner and a nursery,” notes Anthony 
Martin, professor of practice in the Department of Environmental Studies in Emory 
College of Arts and Sciences and the author 
of a new book, Dinosaurs without Bones.

It is coprolites, or fossilized dinosaur dung, that allow us to reconstruct the heartwarming domestic scene described above. Martin's book collects and describes these and scores of other fascinating finds that he and his fellow trackers are using to glean surprisingly intimate insights into how dinosaurs and other prehistoric creatures moved, healed, hunted, ate and excreted.

Read the whole article in Emory Magazine.

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Photo: iStockphoto.com

Resilience: The new development buzzword in the era of climate change

Haile Gebrselassie, shown celebrating after winning a gold medal in the Sydney 2000 Olympic Games, rose from poverty in rural Ethiopia to become an international hero. (Photo by Darren England/AllSport.)

By Carol Clark

Haile Gebrselassie, the former Olympic long-distance runner, grew up poor in Ethiopia. He was one of ten children of a farmer, and developed his athleticism by running 20-miles, round-trip, from his rural home to school each day.

Now 41, Gebrselassie was a featured speaker at the 2020 Conference on Building Resilience for Food and Nutrition Security, held in Addis Ababa last month.

“We had just enough land,” Gebrselassie recalled of his subsistence childhood. The population of Ethiopia has since grown, the country is rapidly urbanizing, and the size of family farms are getting smaller. “On top of that, nowadays there are many other problems,” he said. “My province used to have very nice and cool weather, but the temperature has risen.”

Droughts and other extreme weather events are more frequent, and yet, Gebrselassie is returning to his roots, investing his earnings as an international sports star into an Ethiopian coffee plantation. “I’m doing the same thing I did before, that is farming,” he said in his address. “I’m planting coffee. It’s a better farm, a better way, a modern way.”

Anthropologist Peter Little and long-distance runner Haile Gebrselassie at the conference in Addis Ababa.

“His personal experience of not just getting through a life of poverty, but becoming a holder of 23 world records and two gold medals in the Olympics, is a powerful story of resilience,” says Peter Little, an Emory anthropologist who was also a plenary speaker at the conference.

Little, who has been researching pastoralist communities in the Horn of Africa for three decades, gave a talk about the resilience of these nomadic herders over millennia, and how they face unique challenges today due to climate change, conflict, and loss of land. Pastoralists have managed to weather these new shocks and develop new markets. “A billion dollars in live animals and animal products are exported each year from the Horn of Africa,” Little noted in his talk. He added that pastoralism may evolve into new forms, but it will continue to remain a viable enterprise.

The tri-annual development conference is sponsored by the International Food Policy Research Institute, which is based in Washington, D.C., and part of an agriculture research network funded by governments, private businesses, foundations and the World Bank. Heads of state, academics, and representatives of non-governmental agencies and major corporations were among the 800 invited guests at the event.

“A lot of different actors from the international community are interested in issues of poverty eradication. They are searching for new ideas and new ways of doing development work,” Little says. “The conversation is moving away from the focus on crises, to looking at how to build and promote resilience, especially in terms of drought and other natural shocks.”

Watch Peter Little's conference keynote in the video below:


The Horn of Africa “could be the poster child for the effects of climate change,” he says. The region suffered a major drought and famine in 2011, killing an estimated 70,000 to 100,000 people.

While many presentations at the conference considered the effects of that disaster, the discussions also reflected optimism for the future of the region and for the continent as a whole. “Africa is coming up as a major player in the 21st century, whether you believe it or not,” Little says. About 200 million to 300 million Africans are expected to enter the middle class during the next 10 to 15 years.

“Despite massive problems of poverty and conflict,” Little says, “a growing middle class is making things happen, and a lot of people are focusing on the enormous potential of Africa.”

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Chikungunya virus spreads in Americas, enters U.S. via travelers

The aggressive tiger mosquito, distinguished by its white stripes, can spread chikungunya virus. This mosquito is native to Southeast Asia but has invaded other parts of the world in recent decades, including much of the United States. (Photo by James Gathany/CDC.)

By Carol Clark

As chikungunya virus moves into the Americas for the first time, causing a major outbreak throughout the Caribbean and parts of Central and South America, U.S. health officials are monitoring cases in travelers returning from the affected areas. Imported cases of the mosquito-borne virus have been confirmed in more than a dozen U.S. states, and that number is expected to keep growing.

“Early response is essential,” says Gonzalo Vazquez-Prokopec, a disease ecologist in Emory’s Department of Environmental Sciences who studies how mosquito-borne pathogens move through urban populations. “We need to prepare the country to try to avoid what we suffered with the introduction of West Nile virus 10 years ago.”

Vazquez-Prokopec and Uriel Kitron, chair of Emory’s Department of Environmental Sciences, have been studying the patterns of vector-borne disease epidemics for years and are currently working with public health officials in other parts of the Americas and Africa on chikungunya control efforts.

Kitron will be a featured speaker at a meeting of the NSF-sponsored Urban Climate Institute, hosted by Georgia Tech July 9-10. His talk is titled "Changing Urban Climate and Mosquito-borne Diseases."

The World Health Organization reported the first local transmission of chikungunya in the Western Hemisphere in December of 2013, on the island of Saint Martin. Local transmissions means that mosquitoes in the area have been infected with the virus and are spreading it to people by biting them. Since then, more than 150,000 cases of local transmission have been identified in 17 countries or territories in the Caribbean, Central and South America, according to the Centers for Disease Control and Prevention. Puerto Rico is the only U.S. territory or state that has identified a case of local transmission, the CDC reports.

Chikungunya is rarely fatal but the symptoms can be severe and debilitating, including headache, fever, joint and muscle pain, and joint swelling or rash. While most patients recover within a week, in some people the joint pain can persist for months. Newborns, older adults and people with existing medical conditions are at higher risk for the more severe forms of chikungunya.

The foot of a chikungunya patient in the Philippines shows the characteristic swelling and rash. (Photo by Nsaa.)

There is no vaccine to prevent the disease or medicine to treat infections. The only way to avoid infection is to prevent mosquito bites by using repellent, window/door screens, and reducing the number of mosquitoes by emptying standing water from containers.

The virus is primarily spread to people by two types of day-time biting mosquitoes: Aedes aegypti and Aedes albopictus. While the former is not common in Georgia, the Aedes albopictus, or Asian tiger mosquito, is pervasive. It is that tiny, infuriating, white-striped pest that crashes countless backyard barbecues, and turns many a relaxing summer session in a hammock into a bloody battle.

“They are like the cockroaches of mosquitoes,” Vazquez-Prokopec says, “perfectly adapted to living in urban areas in close proximity to humans. A house is like a microhabitat for both these species, which can breed in the little bit of water collected beneath an indoor flowerpot.”

The tiger mosquito bites not just people but a range of animals, including squirrels, dogs, deer and birds. The Aedes aegypti, however, which thrives in tropical climates like the Caribbean, feeds solely on human blood.

The Aedes aegypti mosquito is the primary spreader of chikungunya in the current outbreak in the tropical region of the Americas. This mosquito species is an especially efficient spreader of human disease since it only feeds on human blood. (Photo by Muhammed Mahdi Karim.)

“No one has immunity to chikungunya in in the Americas, causing it to spread like a fire and create a real problem for public health,” Vazquez-Prokopec says, noting that in poorer countries fewer homes have air-conditioning, or even window screens, to keep mosquitoes at bay.

Once a mosquito become infected, by taking a blood meal from an infected person, the mosquito can then spread the virus if it bites another person.

“The way the virus is propagating, we expect local transmission of chikungunya to make it to Mexico’s Yucatan Peninsula as early as this summer,” Vazquez-Prokopec says. “It’s just a matter of time.”

He is currently coordinating a chikungunya rapid-response effort for the Yucatan Peninusula. The effort involves health officials from the three states making up the peninsula (Yucatan, Campeche and Quintana Roo) as well as researchers from local universities. “We want to use our experience researching mosquito-borne disease propagation to help the local authorities try to predict when and where the virus will move,” Vazquez-Prokopec says. “There are two ways of attacking a fire: You try to contain the fire and you also look at where the fire is likely headed to create a buffer to help extinguish it. We know we are in front of a major challenge,” he adds, “but we hope our approach can reduce the chances of a major outbreak occurring in the peninsula.”

Brazil, which reports the highest number of dengue fever cases in the Americas, is another likely destination for serious outbreaks of chikungunya virus, adds Kitron. He is currently in Salvador, Brazil, a city where dengue is highly endemic, collaborating on an entomological study of Aedes aegypti and Aedes albopictus, which are also vectors for dengue.

Chikungunya virus has long been endemic in Africa and parts of Asia. More recent outbreaks have occurred in Europe and countries in the Indian and Pacific Oceans.

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Sewer upgrade flushes West Nile virus vector from Atlanta stream

About 50 Emory students, mostly undergraduates, worked in the field to gather data for the stream monitoring project.

By Carol Clark

Just 10 years ago, a heavy rain in Atlanta could turn Tanyard Creek into a river of raw sewage. “You would sometimes see toilet paper hanging from low branches along its banks,” recalls Gonzalo Vazquez-Prokopec, a disease ecologist in Emory’s Department of Environmental Sciences.

Few fish or turtles were evident in the stream, which flows alongside expensive Buckhead real estate. But larvae from the Culex quinquefasciatus mosquito, the main vector of West Nile virus in Atlanta, thrived in the polluted waters.

Today, that scene is largely reversed, following the remediation by the city of Atlanta of a combined sewage overflow (CSO) facility connected to Tanyard Creek. A five-year study led by Emory researchers gathered the before-and-after data to prove it.

“This is the first study that shows how the construction of a deep storage tunnel for a CSO system not only improves stream health and water quality but reduces the mosquitoes that spread West Nile virus,” Vazquez-Prokopec says.

The journal Environmental Research published the study’s results, which could help guide interventions for cities across the country dealing with problems of aging sewage systems and burgeoning populations.

“Our data provide evidence for how a particular cost-saving technology can work to significantly reduce both pollution and disease vectors,” Vazquez-Prokopec says.

About 50 Emory students, mostly undergraduates, worked in the field to help gather the data for the project. “I now use the research in my ‘Urban Ecology and Development Class’ to introduce students to the levels of impairment that urban streams can suffer,” Vazquez-Prokopec says.

In addition to Vazquez-Prokopec, the study’s co-authors include Andrea Lund, Joseph McMillan, Shirin Jabbarzadeh and Uriel Kitron (all from Emory’s Department of Environmental Sciences); Rosmarie Kelly from the Georgia Department of Public Health; Daniel Mead from the University of Georgia; and Thomas Burkot from James Cook University in Australia.

Toilet paper hangs from the underbrush alongside Tanyard Creek, following a heavy rain in 2008.

Cities alter the natural environment in myriad ways, and one of the most obvious is water pollution. Sewage, chemicals and heavy metals wind up in creeks, streams and rivers.

More than a century ago, many cities in the United States combined their sewer lines from buildings with runoff from streets. When populations were smaller and fewer surfaces were paved, the sewage pipes were generally large enough to handle the combined flows, and the systems only rarely overflowed.

Today, however, many of the more than 700 cities across the country using CSO systems are facing an environmental crisis. During periods of heavy rain, the wastewater flows directly into natural waterways after only minimal chlorine treatment and sieving to remove large physical contaminants.

Congress had passed the Clean Water Act in 1972, calling for zero discharge of pollutants into fishable and swimmable waters by 1985. Atlanta was among the many cities that failed to achieve this goal even by the late 1990s. After heavy rains, federal water-quality monitoring stations along the Chattahoochee River have recorded as much as 20,000 colonies per liter of e-coli fecal chloroforms, essentially traces of human feces.

Under the pressure of lawsuits, and enforcement action by the U.S. Environmental Protection Agency, Atlanta began remediation efforts. The city eventually won an extension to 2027 to complete the system upgrades.

In June 2008, when Emory’s Department of Environmental Sciences began its water quality study, Tanyard Creek was one of the most polluted streams in the city. “Just one-quarter-inch of rain was enough to initiate a sewage overflow,” Vazquez-Prokopec says. “Tanyard Creek was subjected to more than 40 overflows per year, totaling about 150 million gallons of sewage.”

Gonzalo Vazquez-Prokopec shot this video of a sewer overflow after an Atlanta downpour:


Chemical analysis of water samples from the creek showed high levels of ammonia, nitrogen and phosphorus. Worms that thrive in this type of pollution were moving about Tanyard’s waters, but most of the fish the researchers encountered were dead. “Ammonia, in particular, is food for bacteria and algae, which had overgrown and depleted oxygen levels to the point that fish couldn’t breathe,” Vazquez-Prokopec explains.

The researchers also recorded the amount and types of mosquito larvae and pupae in the water. Culex mosquitos, which can carry the West Nile virus and transmit it between birds and other animals and humans, were teeming in the polluted waters. Cup-sized Tanyard Creek water samples typically had more than 1,000 Culex larvae and pupae, compared to almost none in samples from Peavine Creek. (Peavine, which flows through the Emory campus, is a healthy urban stream not subjected to CSOs, and was used as a control in the research.)

City of Atlanta graphic of deep storage tunnel

A new deep storage tunnel for the CSO facility connected to Tanyard Creek became operational in November of 2008. The tunnel was a less expensive fix than installing larger sewage pipes, and it is able to contain most of the CSOs coming from Midtown Atlanta. A total of 42 sewer discharges were recorded at the facility in 2008, none were recorded in 2009, and only one in 2011 and two in 2012. The total annual volume discharged from the CSO facility was reduced from 154 million gallons in 2008 to six million gallons in 2012.

The effects of the remediation effort were dramatic, Vazquez-Prokopec says. “From 2008 to 2009, it was like, ‘Boom!’”

The before-and-after data showed the water quality continued to improve through October of 2012 when the study was completed. “The ammonia and nitrate levels were down, and the oxygen levels went from really low to normal,” Vazquez-Prokopec says. “We’re seeing an urban stream as healthy as an urban stream can be, with wildlife coming back, including turtles, tadpoles, frogs and water snakes. And the main vector of West Nile virus is disappearing.”

A cup-sized dip of water from Tanyard Creek that previously contained hundreds of Culex mosquito larvae now may have 10 Culex larvae, Vazquez-Prokopec says.

Atlanta has about 40 different species of mosquitoes, he notes. The Culex is the main species that can carry the West Nile virus in the city, and it happens to prefer polluted waters, making the old CSO system and frequent heavy rains a perfect storm for an outbreak of the disease.

Rapid urban growth means rapid changes throughout an ecosystem, a fact that will increasingly present challenges to public health. “In 2007, the human world population shifted from primarily rural to more urban,” Vazquez-Prokopec says. “That’s a huge and important milestone in history. We have to understand that our own health is not separate from the health of the environment.”

Photos courtesy Gonzalo Vazquez-Prokopec

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