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Science Wednesday: Biodiversity, Mosquitoes, and Health, Oh My!

Wednesday, September 16th, 2009

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

It was 0630 and although the sun was beginning to rise, it was still very dark within the tropical forest. Following a 20 minute ride in a small boat, we had arrived at a remote trail on the island and were now navigating the trail to check the CO2/light traps set the night before. The illuminated traps were beacons in the sea of dark forest, and we hoped they’d be filled with mosquitoes. The forest was peaceful in the early morning light, except for the occasional bouts of grunting from the howler monkeys or an agouti crossing the trail.

I never imagined working at EPA would lead me to Barro Colorado Island (BCI), a former mountain top that became an island when the Panama Canal was created in the early 1900s. Now a natural monument, it was the setting of the inaugural sampling event for a joint project between EPA and the Smithsonian Tropical Research Institute (STRI).

The project explores the link between biodiversity, insect vectors (those capable of passing a pathogen one animal to another), and disease. The connection between biodiversity (the number and abundance of difference species) and disease is complicated, but we know that sometimes changes in biodiversity (specifically, the loss of structural diversity) can increase the abundance of certain disease-carrying vectors. In turn, this can increase the risk of humans coming into contact with the disease-transmitting vector. Human activities, such as encroaching into new areas to build houses or clear land for farming, can change local biodiversity.

The STRI-EPA project focuses on mosquitoes and how changing biodiversity in “natural” and anthropogenic landscapes affects vectors of public health importance.

Back at the lab, we began the monumental task of sorting through the traps’ contents. Thankfully, I was surrounded by insect experts who were able to show me exactly what to look for among the tiny copious critters. Microscope and forceps in hand, I started sorting and sorting…. Hours later, sorting complete, we separated mosquitoes and sandflies (another vector important to public health) by species into groups of 50 or fewer. Specimens were placed into vials and frozen. The samples will be analyzed later to see what kinds of pathogens the insects were carrying, if any.

image of author wearing orange lifejacket Over this next year, sampling will continue at BCI. We plan to expand sampling into nearby, land-disturbed areas inhabited by people so that mosquito diversity and disease risk can be compared with that of BCI.

About the Author: Meghan Radtke, Ph.D. is an AAAS Science and Technology Policy Fellow at EPA. Her fascination with biodiversity and tropical forests inspired her to join the Biodiversity and Human Health research effort.

Science Wednesday: Sustaining Tropical Forests

Wednesday, September 9th, 2009

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

The Amazon basin contains more than half the world’s remaining tropical rainforest, and is facing unprecedented changes that will have major impacts on biodiversity, regional hydrology and the global carbon cycle.

But the need for employment is causing tropical deforestation on a vast scale.

Stopping deforestation requires forest management strategies that provide jobs for people living in or near forests while also creating incentives for forest conservation. The andiroba tree (C. guianensis)- valued for the high-quality oil extracted from its seeds and for its mahogany-like timber—could provide this opportunity.

Collect the seeds, cut down the tree, or a little of both?

image of author standing on a root of a big tree over waterThrough my research, I am looking at the intersection of conservation and economics related to harvesting C. guianensis. I am using ecological models with an economic component to answer the question: Under what ecological and market conditions would the collection of C. guianensis seed oil be favored and, conversely, under what ecological and market conditions would C. guianensis timber harvest be favored?

Since 2004, I have been measuring growth, survival and reproduction of C. guianensis trees at my research site in the Brazilian Agricultural Research Institute’s 1,200-hectare research forest in Acre, Brazil.

Using these measurements, I plan to fine-tune models about future tree growth under various management scenarios, as well as identify how different life stages, such as seedlings, saplings, mature trees, etc., contribute to growth of the entire tree population. For example, it is possible that leaving a certain number of reproducing trees per hectare would maintain a growing population, leaving other, non-reproductive trees to be harvested?

I will use the new model to determine sustainable harvest limits for both timber and seed, and then incorporate the results into a financial assessment of these two competing strategies to manage the species. To ensure that the tree population is maintained and that it generates income, I plan to compare the relative compatibility of timber vs. seed harvest.

After I finish writing up my results, I will return to Brazil to give a series of training workshops and seminars on my results so they can be applied to forest management practices. In addition, I will compile materials (including comic-book-like illustrated pamphlets) that break down my results into tools that can benefit forest residents and local nongovernmental organizations. By sharing my research results in this way, I hope that I can provide important information to the local Brazilian government and play a part in helping people living near the forest find a sustainable way to create income based on a standing (or managed) forest.

About the author: Christie Klimas is a PhD student at the University of Florida in the department of Forest Resources and Conservation. A 2004-2006 EPA Science to Achieve Results (STAR) Graduate Research Fellowship supported her Master’s Degree research.

Year of Science Question of the Month: How Do You Think Biodiversity Affects You?

Wednesday, September 2nd, 2009

For each month in 2009, the Year of Science — we will pose a question related to science. Please let us know your thoughts as comments, and feel free to respond to earlier comments, or post new ideas.

The Year of Science theme for September is Biodiversity and Conservation. Biodiversity is a catch-all term that refers to the variety of life at all levels, from the range of genes within in a breeding population (more genetic diversity helps to prevent inbreeding problems), to how many different species there are, all the way to the variety of different ecosystems. EPA scientists are exploring how biodiversity is linked to human health and well being.

How do you think biodiversity affects you?

EPA and the Smithsonian: Partnering in a Land Use and Biodiversity Study

Wednesday, September 2nd, 2009

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

In March 2007, an agency-wide Memorandum of Understanding (MOU) with the Smithsonian Institution (SI) was signed, recognizing a shared interest in collaborating to promote intellectual exchange and the advancement of education and outreach on a wide range of scientific topics.

One of the areas in which we have been working in partnership with the Smithsonian is in studying the relationship between land use, biodiversity, and human health. Smithsonian Tropical Research Institute’s (STRI) network of tropical forest plots is being developed into a system of Smithsonian Institution Global Earth Observatories (SIGEO), which has and will continue to provide critical scientific data about how tree biomass and biodiversity are responding and adapting to increases in atmospheric CO2 and global warming. In addition to modeling the global carbon budget, we recognized that SIGEO serves as an excellent platform to explore the dynamics and mechanisms underlying the relationship between anthropogenic stressors, changes in biodiversity, and disease transmission to humans because the sites have been so well characterized ecologically. EPA and STRI are working together to inventory and monitor important animal groups such as vertebrates and arthropods that can play important roles in human disease transmission.

Why is this a timely research opportunity? Mosquitoes are medically the most important group of Diptera, both in the numbers of disease agents they transmit and the magnitude of health problems these diseases cause worldwide, and climate change is predicted to expand vector range and exacerbate disease.

Our collaboration will use appropriate temperate and tropical plots that are part of the SIGEO network to assess the status and trends of mosquito species populations over time and evaluate whether infectious disease transmission risk is being altered in response to changes in climate and surrounding land-use. CDC has also joined as a partner to evaluate collected mosquitoes for the presence of arboviruses of public health importance and identification of the vector species they are utilizing in distinct habitats. Comparison of the findings from this study with an ongoing CDC study of arbovirus presence in nearby Guatemala will provide a better estimate of the risk of human and animal epidemics due to movement of zoonotic arboviruses throughout Central America. Mosquito monitoring will also add new information to Smithsonian’s MosquitoMap, a new web-based, geospatially referenced clearinghouse for mosquito species collection records and distribution models.

EPA is working with STRI, CDC, Smithsonian Museum Support Center, and the Gorgas Memorial Lab in Panama.

For more information on EPA’s Biodiversity and Human Health activities, see:
http://www.epa.gov/ncer/biodiversity

About the author: Montira Pongsiri, PhD, MPH, is an Environmental Health Scientist in EPA’s Office of the Science Advisor.

Science Wednesday: Ready for Takeoff

Wednesday, August 26th, 2009

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

While I’ve come to expect extra scrutiny when flying, I was momentarily flustered when the pilot needed to know my weight so he could compute his preflight plans. (155 pounds.)

This morning I joined Eric Vance, EPA’s chief photographer, EPA scientist Steve Klein,  and U.S. Fish and Wildlife Service pilot V. Ray Bently aboard a four-seat, single-engine plane for a flight over the Willamette River Valley in western Oregon.

arial view of winding riverThe landscape we flew over is the subject of the Willamette Ecosystem Services Project (WESP), an ambitious, large-scale, integrated, and multi-disciplinary research effort to quantify the benefits people derive from the environment. The study also focuses on exploring how human activities stress those benefits. The overall goal is to provide decision makers, stakeholders, and others across the Willamette River Valley with rigorous scientific information they can use to assess current conditions and plan for the future of their community.

All told, the Willamette River Valley Ecosystem includes some 7.5 million acres. To get a better picture of what’s happening across such a large area, it helps to get a bird’s eye view.

Time to fly.

arial view over trees and winding riverOur flight took us over the Willamette River as it winds from Corvallis to the suburbs of Eugene, a diverse and productive landscape. Over the drone of the engine and intermittent blasts of cool air that roared into cockpit when Eric opened his window to take pictures, Steve explained what he was seeing from a scientist’s perspective: how the flow and course of the river has been shaped by human forces, the patterns and types of forest and other natural habitats, what types of crops where growing in the large agricultural fields below, and the shifting boundaries between agriculture, forest, and what he referred to as “the built environment” (homes, roads, and industry, including the massive paper mill we could not only see, but smell—a thick, burnt-syrup kind of aroma).

My flight was just one of the many excellent experiences I’ve had this week visiting with scientists in EPA’s Western Ecology Division. I’ve learned about research projects as diverse as the 7.5-million-acre WESP, to plans to investigate the potential environmental impacts of things as tiny as those used in nanotechnology.

It’s been a great week and I’ll have lots to think about on the flight back to Washington. I won’t even flinch if the pilot asks me how much I weigh.

About the Author: Aaron Ferster is the chief science writer in EPA’s Office of Research and Development. He is the Science Wednesday editor, and a regular contributor.

Science Wednesday: The Challenges and Rewards of Health Assessment

Wednesday, August 19th, 2009

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

Conducting health assessments for chemicals at EPA involves synthesizing the available scientific literature on a particular chemical and determining the health risks that the chemical poses to humans. Personally, I find it fulfilling to be involved in this type of career because the information is useful to the public.

Being a health assessor is rewarding but there are also several challenges in determining how a chemical might act in the human body. One challenge is determining the effect of a chemical in the body when you don’t know much about the toxicological data. There are sophisticated tools, such as microarray analysis and structure-activity analysis, to study compounds with limited information. In microarray analysis, scientists treat particular genes with a chemical and then monitor the results. So if a data-poor chemical has a similar gene profile to an endocrine disrupting chemical, then we hypothesize that this chemical could be a potential endocrine disruptor. Structure-activity analysis helps classify a compound based on its chemical structure. Both of these types of analyses can be completed quite quickly to understand how these data-poor chemicals could act when humans are exposed.

It is also quite challenging when a chemical has been studied extensively. When there is a lot of research on a chemical, arguments sometimes arise about the validity of the research or if a chemical is actually responsible for a resulting health effect. To add to the confusion, although there could be several studies on a chemical, they might not necessarily indicate a clear health effect. In some cases, chemicals have many studies showing health effects in animals but no evident effects in humans.

As health assessors, we generally assume that humans are more sensitive to health effects than animals. Therefore, if a chemical causes toxic effects in animals, then humans should be more susceptible. To reduce this uncertainty, it is important to understand the difference in a chemical’s effect between animals and humans.

Even though there are challenges in evaluating the health risks of chemicals to humans, it is rewarding to know that this information can be used to help keep people healthy. Overall, my job is to understand the potential health risks that could arise from exposures to chemicals in the environment.

About the author: Ambuja Bale works as a risk assessor in EPA’s National Center for Environmental Assessment. She has a PhD in Pharmacology and Toxicology.

Science Wednesday: Making Climate Change the Next “Hot” Topic

Wednesday, August 12th, 2009

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

“So how are we going to do this?” was the first question on our lips after we accepted an invitation to speak to a group of middle school students in EPA’s Student Environmental Development Program.  As scientists who focus on highly technical research questions to inform expert stakeholders, it was a rather scary prospect to attempt to convey what we do to a group of 8th graders. How could we discuss our research on climate change effects on the environment in a way that would be fun as well as educational?

What our guest appearance turned out to be was as much a fun, learning experience for us as we hope it was for the students.

“Does anyone know what the difference is between “climate” and “weather”?” Susan asked, as a means of opening her discussion on climate change.  What followed was a delightful and varied array of opinions and anecdotes from the enthusiastic students. We realized that this was an issue that the students were eager to learn more about.

“What is risk? What is adaptation?” Amanda illustrated these concepts with an example of shark attacks at swimming beaches, and asked the students to give examples of ways that communities could reduce risks to swimmers. Their idea of patrolling and marking “safe swimming areas” with buoys was an example of an adaptation, and provided an easy transition into discussing adaptations to climate change by wetlands managers.

“Is a coral an animal or a plant?” Jordan used corals and their sensitivity to climate change to lead the students in an exercise based on a real project in Kimbe Bay, Papua New Guinea. The students were asked to assume the role of coral reef managers and design a network of marine protected areas that would be most resilient to climate change. After only a brief “ training” in concepts of coral biology, physical oceanography, socioeconomics, and resilience theory, the students were surprised and excited to find that they chose the same coral reef areas for protection that a group of experts did!

We hope that this experience showed the students that, while climate change is a serious problem, there is a large community of scientists, managers and concerned citizens who are exploring and implementing actions to address the severest effects on the environment. What we learned was that the complex issues that we study in our research program can indeed be understood and appreciated by any age group. In fact, it is eager and motivated students such as these who will take up the mantle of “saving the world”.

About the authors: Jordan West, Susan Julius, and Amanda Babson work together in EPA’s Global Change Research Program, where they love to debate with their colleagues on how best to” save the world”.

Year of Science Question of the Month: How is climate change affecting the things you care about, and how do you think it will affect what you care about in the future?

Wednesday, August 5th, 2009

For each month in 2009, the Year of Science—we will pose a question related to science. Please let us know your thoughts as comments, and feel free to respond to earlier comments, or post new ideas.

The Year of Science theme for August is Weather and Climate.

How is climate change affecting the things you care about, and how do you think it will affect what you care about in the future?

Science Wednesday: Science To Support Decision Making In A Changing Climate

Wednesday, August 5th, 2009

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

During my 22 year career at EPA, it’s been exciting to work on the environmental issue which has been called the “capstone issue for our generation”: climate change. Climate change affects every individual in every community around the world. The team I am a part of at EPA is working closely with communities around the country to shed light on how climate change affects the things they care about, and to find ways to respond and adapt to its impacts.

There’s nothing more rewarding than meeting the people who are benefitting from the science we’re doing. It’s one thing to work in a laboratory or office and explore strategies and develop tools to help local communities respond to climate change. It’s another thing to actually meet the people whose lives you are touching.

image of a house falling onto a beach near the water\'s edgeI first had that chance in 2007 when I traveled to Alaska and met people from several Native Alaskan villages such as Shishmaref, Newtok, and Kivalina. I listened to heart-wrenching stories about how they must soon evacuate their coastal villages because homes and infrastructure are being destroyed by rising sea levels, storm surges, and the melting of the permafrost upon which they sit. I was faced with the stark realities of a changing climate, not with some “plausible projection” from one of our climate impacts models.

When I first started working on climate change, people imagined it to be something that wouldn’t happen for another 50 to 100 years. We quickly came to understand that the climate is already changing. It’s changing more and more rapidly as a result of human activities. When we burn fossil fuels to power our automobiles and run our factories and heat our homes, we emit greenhouse gas pollution which contributes to global warming. And we’re already seeing the impacts of global warming on peoples’ lives.

My own appreciation for the critical importance of the work we’re doing in our Global Change Research Program at EPA rose dramatically during that visit to Alaska. We’re empowering people to protect their communities and the things they value by providing the scientific information that enables them to anticipate the effects of a changing climate, developing alternative strategies for them to adapt to change, and providing tools that can help them incorporate considerations of climate change into their day-to-day decisions. We are making a difference in people’s lives.

About the author: Dr. Joel Scheraga is the National Program Director for EPA’s Global Change Research Program in the Office of Research and Development. He has been with EPA since 1987. He is also the EPA Principal Representative to the U.S. Global Change Research Program, which coordinates and integrates scientific research on climate and global change supported by the U.S. Government.

Science Wednesday: The Changing Environment – What Does It All Mean?

Wednesday, July 29th, 2009

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

The state of the nation’s environment is changing. Sometimes the changes are obvious and sometimes they are subtle. When does it matter and why should we care?

One of the more visible and memorable events of the early environmental movement was when the Cuyahoga River, which runs through the heart of my hometown of Cleveland, Ohio, caught fire in 1969. Some say that it was this event that prompted President Nixon to sign the Clean Water Act into law and create the Environmental Protection Agency.

The River that once burned now runs through a lively and bustling downtown area to Lake Erie. This is not to say that the water quality in the river and lake are now pristine, but that the improvements over time are so profound that it’s noticeable to the naked eye.

Even here in Washington, D.C., there are ways to observe environmental progress. I am lucky enough to garden in the city—a rare treat in the concrete jungle. Over the years I’ve observed changes in the insects and birds that visit our garden. Last spring my bachelor buttons were swarming with bees. This year, however, there weren’t as many.

What should I make of these changes in nature’s pollinators and natural pest management? What should our garden, city, and country do? Are the changes even relevant and is it appropriate for me to draw any conclusions? After all, I’ve only observed these changes while in pursuit of some other goal, such as watering my tomatoes, or driving through downtown Cleveland to catch a ball game.

If you find yourself wondering about the changing state of the nation’s environment and what it all means, there is one place you can go to find objective, scientifically sound information: EPA’s Report on the Environment.

EPA released its Report on the Environment (ROE) in May 2008 and has been updating it online ever since. It’s here that you can find information on the nation’s bird populations, stream water quality, air quality, and much more.

The ROE uses environmental indicators to present the status (i.e. condition) of and trends in (i.e., are things improving or not) for 85 different measurable areas of our nation’s environment in land, water, air, human health and ecosystems.

Check out the interactive Web site to see for yourself and tell us what you want to know about the nation’s changing environment.

About the author: Madalene Stevens joined EPA in 2001 and works on EPA’s Report on the Environment.