Greenversations

Each week we write about the science behind environmental protection. Previous Science Wednesdays. While Kermit the Frog’s famously laments that it is not easy being green, it is becoming increasingly clear that we have no choice but to develop innovative and creative ways to minimize our impact on the environment. For the past 35 years or so, I’ve been involved in searching for ways that science—chemistry in particular—can help.

Chemistry has become so important to modern life that it’s virtually at the center of everything we make. That’s why the development of “green chemistry” is so important. The 12 principles of green chemistry have been laid out very clearly, focusing on reducing, recycling, or eliminating the use of toxic materials in chemical synthesis or manipulations.

The first wave of green chemistry research focused primarily on replacing the use of toxic, volatile organic solvents by using microwaves, ultrasound, and photochemistry. Now, I’m excited to be involved in the next generation of green chemistry research, exploring the use of nanomaterials (particles 100 nanometers or smaller—a nanometer is about 100,000 times smaller than the width of a human hair).

One big question we asked ourselves was “why not use a single compound that nature uses to build nanomaterials from a single, environmentally-benign source?” Turns out it was a good question. We discovered that we can use almost anything to reduce metal salts, including vitamins (B1, B2, and C), tea and wine polyphenols, and natural surfactants, to their nano forms. This newer thinking provides a simple, one-pot, greener synthetic alternative to bulk quantities of nanomaterials, as compared to conventional methods that use toxic reagents.

We also discovered that we could easily synthesize noble, uniform-size nanostructures using microwave (MW) heating (yes, the same used in the kitchen). Using this technology, we’ve developed extremely strong and light materials by cross-linking polymer matrices into carbon nanotubes.

What’s next? How about making biodegradable cellulose composite films with nanometals? We figured out how to do that heating the salts with carboxymethylcellulose (CMC), essentially the same compound found in the diet supplement Metamucil, facilitates the alignment of carbon nanotubes.

Green chemistry means green jobs, too. We are already working with VeruTEK, a Connecticut-based company this is using patented nanotechnology for green environmental remediation (clean up) by using zerovalent iron, also known as ‘iron nanoparticles’. They have created lots of Green jobs while targeting pollutants in soil and water.

About the author: Dr. Rajender (Raj) S. Varma was recently awarded the Visionary of the Year Award at the Green Technologies fo rthe Environment Conference held in Bloomfield, Ct. Varma is a research chemist with EPA’s National Risk Management Research Laboratory.

As parents, we all want what’s best for our children and like to see them grow healthy. I have taught my daughters to wash their hands, eat nutritious meals, wear protective equipment when practicing sports, and to wear sun block. Now that they are teenagers, I talk to them about the dangers of smoking, drinking and drugs, and of course…boys. However, working for the EPA has given me an increased awareness about another set of dangers—environmental exposures.

In recent years, there has been an increased emphasis on protecting children from environmental contaminants and learning how the differences in behavior and physiology affect their exposures. I remember as a child playing with mercury, pouring it on the floor and pushing the silver blobs around with my fingers to form a bigger blob. We didn’t know it was bad for us, and neither did our parents.

Since then, the potential health effects from exposure to mercury and other toxic chemicals such as lead, arsenic, and pesticides have become the focus of environmental policies. We have also learned that diet is an important route of exposure to pesticides and other substances in the environment.

But, why are children a concern and how are their exposures different from those of adults?

Children’s organ systems are still developing and they may be more susceptible to environmental exposures. Their behavior and habits can also put children at higher risks. We have learned that contaminants can be deposited in toys and objects that children put in their mouth. Contaminants can also find their way into the milk of lactating mothers. Another example: on average, children younger than one year old inhale approximately six times the amount of air by body weight than an adult.

I love that my job helps me learn about keeping my kids healthy. But, even if you don’t work here, EPA has developed lots of useful information to share. Our Children’s Health Protection web site is a great place to start if you are looking for generalized information. One source I’ve been involved with, the Highlights for the Child-Specific Exposure Factors Handbook, provides risk assessors, economists, and others a wealth of data and EPA recommendations on exposure factors needed to estimate childhood exposure to toxic contaminants.

About the author: Jacqueline Moya is a chemical engineer with EPA’s Office of Research and Development. She has been with EPA for 25 years. Her work focuses on increasing our understanding about exposure to susceptible populations.

Como padres, todos queremos lo que es mejor para nuestros hijos y nos gusta verlos crecer sanos. Le he enseñado a mis hijas a lavarse las manos, comer comidas nutritivas, usar equipo protector cuando practican deportes y a usar protector solar. Ahora que son adolescentes, les hablo sobre los peligros del fumar, beber y usar drogas y claro… de los varones. Sin embargo, trabajando para la EPA me ha dado una mayor conciencia acerca de otros peligros — exposiciones a contaminantes ambientales.

En los últimos años, ha habido un mayor énfasis en la protección de los niños contra los riesgos a la exposición a contaminantes ambientales y aprender cómo las diferencias de comportamiento y la fisiología afectan a esos riesgos. Recuerdo cuando era niña jugaba con mercurio, lo vertía sobre el suelo y con mis dedos empujaba las pequeñas bolitas plateadas hasta formar bolitas más grandes. Ni nuestros padres ni nosotros sabíamos que era malo para la salud.

Desde entonces, los posibles efectos en la salud debido a la exposición al mercurio y otros productos químicos tóxicos como el plomo, arsénico y pesticidas, han impulsado las políticas ambientales. Hemos aprendido que la dieta es una ruta importante de exposición a pesticidas y otras sustancias en el medio ambiente.

Pero, ¿por qué son los niños una preocupación y cómo se diferencian de los adultos? Los sistemas del organismo de los niños están en desarrollo y pueden ser más susceptibles a la exposición a compuestos ambientales. El comportamiento de los niños y sus hábitos también pueden ponerlos a mayores riesgo de exposición. Hemos aprendido que los contaminantes pueden ser depositados en los juguetes y objetos que los niños llevan a su boca. Los contaminantes también pueden ser encontrados en la leche de madres lactantes. Otro ejemplo: en promedio, los niños menores de uno año inhalan aproximadamente seis veces la cantidad de aire por el peso corporal que un adulto.

Me encanta que mi trabajo me ayuda a aprender acerca de mantener a mis hijos sanos. Pero si no trabaja aqui, EPA ha desarrollado mucha información útil que comparte con el público en general. Nuestra página cibernética para la Protección de la Salud de los Niños es un buen sitio para comenzar si quiere buscar información en general. Una fuente de información en la que he estado envuelta es el informe titulado Highlights for the Child-Specific Exposure Factors Handbook, que provee a los analistas de riesgo, economistas, y otros con información sobre factores de exposición necesarios para estimar la exposición de los niños a los contaminantes tóxicos.

Sobre el autor: Jacqueline Moya es una ingeniera química con la Oficina de Investigación y Desarrollo. Ha trabajado en EPA por 25 años. Su trabajo se concentra en aumentar nuestro entendimiento sobre la exposición en las poblaciones susceptibles.

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

Nearly a decade ago when I was approaching my 40th birthday, I decided to confront mid-life crisis by taking up long-distance running. Specifically, I set my sights on running a marathon. Before making this decision, I had never run more than three or four miles. So 26.2 was an intimidating prospect. I run in about one-yard strides, so a quick calculation told me that it would take me 46,112 of those choppy strides to cross the finish line.

It seemed overwhelming.

But on Thanksgiving day, 1999, I began with a three-mile run, a week later extended it to four miles, and so on until – one year later – I finished my first marathon. I’ve since run four more. It was all about building up endurance, one stride at a time.

This idea of one-step-at-a-time progression is pretty much the same when it comes to trying to understand the possible environmental impacts of nano-sized particles—tiny manufactured particles that are 100 nanometers or smaller. (A nanometer is 1 billionth of a meter, or about 100,000 times smaller than the width of a human hair.) You start with a little bit of knowledge – say, for example – that you know the size and shape of the particle – and build on that to understand whether the size and shape of the particle at the nanoscale makes the particle behave any differently than a larger-sized particle of the same material.

Let’s take, for example, silver, even though I will never win a medal of that color (and surely not gold and, sigh, not even bronze) in any of my marathons. Nano-sized versions of silver are being made for use in clothing, medical equipment, and other things because it is very good at killing bacteria.

Some of our first steps in the nanosilver marathon are to understand if nanosilver behaves differently than larger-sized silver (which we already know quite a bit about). Then we build on that to learn if any differences we find make nanosilver more (or less) toxic than larger silver. And we keep going from there, pushing the limits of our understanding to learn still more.

Be sure to keep an eye on Science Wednesday next month for training tips and things we’re picking up along the nanotechnology course. To learn more about how Jeff Morris is taking the long view of tiny particles, visit EPA’s Nanotechnology Research web site.

About the author: When he’s not running marathons or training for one, Jeff Morris is National Program Director for Nanotechnology in EPA’s Office of Research and Development.

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 October is Geosciences and Planet Earth.

Geoscientists study the composition, structure, and other physical aspects of the Earth. An environmental atlas is a product of geosciences.

What would you like to see in an Environmental Atlas about a place that you are familiar with?

Each week we write about the science behind environmental protection. Previous Science Wednesdays.
I’ve never been much of a multitasker. Perhaps it stems from my preferred mode of transportation. As a bike commuter, texting on the way to work is really out of the question. So, I was really stressing when I realized today’s Science Wednesday blog post had to pull double-duty: follow the year-long pattern of aligning topics for the first post of the month with the 12 themes for Year of Science, and helping EPA celebrate October as Children’s Health month.

Then I checked out this month’s Year of Science theme: “GeoSciences and Planet Earth.” Piece of cake. What do EPA research efforts in geoscience and planet earth have to do with children’s health? A lot, actually. (Thanks for asking!)

To start, EPA is helping lead a national and international effort to build the Global Earth Observation System of Systems (GEOSS), a vast, coordinated network of earth observations, environmental monitoring technologies, datasets, and tools. GEOSS will bring together existing and new hardware and software, making it all compatible in order to supply data and information to environmental managers and health officials.

GEOSS promises to pay big dividends, including reducing disasters, helping people better manage the risk of Lyme disease, and improved water and air quality forecasting.

What makes these benefits particularly important for children’s health is that children, for a variety of reasons including their small size, behavior, and the fact that they are still growing, are often at greater risk to environmental threats than us big people.

Harnessing the collective power of a wealth of geoscience efforts is a great investment in the future of our children. But come to think of it, I’m not sure there are any EPA research efforts that don’t, at least in some way, benefit children. Keep an eye on Science Wednesday throughout the month to read about more examples, from EPA’s Children’s Environmental Health Centers, to a recent report highlighting a decade of children’s environmental health research from EPA’s Science to Achieve Results Program.

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.

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

“Amber waves of grain” conjures up images of vast expanses of grassland across middle America. In contrast, can you picture meadows of seagrasses covering broad areas of the seafloor?

Seagrasses are underwater marine flowering plants that have long, narrow leaves. Because they photosynthesize, seagrasses must grow in shallow water where light penetrates. Most of the light required for these plants disappears below 30 feet.

Florida alone has about a half-million acres of seagrass meadow.

Seagrasses provide essential “ecological services,” such as reducing erosion, improving water quality, and supplying refuge and food for aquatic animals. They are vital to commercial and recreational fisheries that are a major part of a coastal community’s economy.

Unfortunately, the health of seagrass meadows has been compromised in many places due to pollution from land-based activities. Excess nutrients from fertilizers and wastewater cause algal blooms which deprive seagrasses and aquatic organisms of essential oxygen. In addition, over-fishing, over-crabbing, and other harvesting practices change the ecological balance within seagrass meadows, leading to shifts in both plant and animal populations.

My PhD thesis brings me to the shallow waters off Bermuda where I am measuring the simultaneous effects of heavy grazing and excess nutrients on the overall health of seagrass pastures. Seagrasses here are being eaten (grazed) by green turtles and parrotfish while fertilizer runoff is also affecting them.

My main focus is to understand how grazers with different feeding strategies—where and how they feed—control the effects of nutrient pollution. I am working in both the laboratory and the field to manipulate and measure nutrient levels.

A conservationist at heart, I constantly seek to educate others about how human actions can either positively or negatively impact the physical environment. My research looking at the indirect effects of local fishing practices and wastewater treatment on seagrass ecosystems has pressing applications for coastal conservation and management worldwide.

About the author: Kim Holzer is a Ph.D. student in the Department of Environmental Sciences at the University of Virginia. Funding for her research is provided by a 2007 EPA Science to Achieve Results (STAR) Graduate Research Fellowship. Kim expects to graduate in the spring of 2011 and continue working as a scientist in environmental protection.

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

Whenever someone in my office says, “You’d be the perfect person for…,” my first thought is always this can’t be good. But when the “perfect” assignment was an invitation to teach 7th and 8th grade scientists attending the Summer Educational Development Program about what my colleagues and I do at EPA’s National Center for Environmental Assessment (NCEA), I immediately agreed.

My next thought, however, was “how do I make Human Health Risk Assessment , interesting to 12- and 13 year-olds?” Yikes!

I decided to start the conversation about risks the students might face in every day life. Things like traffic and playing sports on hard asphalt. Or sharks. We went from there to discuss how one might reduce these every day risks, or “risk management” in the form of using crosswalks or the help of crossing guards.

We then talked about how we at EPA use the NAS Risk Assessment paradigm (hazard identification, dose-response analysis, and exposure assessment) to determine chemical risk. I used the shark example to explain the need to consider both “hazard” and “exposure” in risk assessment. While a hungry shark may be a hazard, we all agreed that there’s not much an exposure risk to us in the classroom. (Well at least we hoped not!).

With no sharks to worry about, I moved the discussion to something we here at EPA are more concerned about: lead. In the context of the four-step risk assessment paradigm, we explored the human health risk assessment of lead to describe determining hazards and risk levels that would result from various exposures.

To end, we talked about how genetics might make one population more susceptible to exposure risk than another population. Using a simple experiment on taste, everyone determined if they were a genetic ‘Taster’ or ‘Non-Taster.’ We talked about how if being a ‘Taster’ was a risk, and only three people in the class can ‘Taste,’ than identifying their presence would impact a risk assessment. This helped the students grasp the importance of understanding susceptible populations in risk assessment, and how smaller subpopulations may be impacted by risks not generally seen in the bigger population.

The energy and enthusiasm that the class brought to the discussion, and their quick understanding of the importance of risk assessment made me all the more energized about what I do every day. I am looking forward to my next perfect assignment.

About the author: Dr. Maureen Gwinn is a toxicologist with the National Center for Environmental Assessment in the Effects Identification and Characterization Group where she works in Human Health Risk Assessment. Dr. Gwinn enjoys doing toxicology outreach with students through the Society of Toxicology’s Education Committee.

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.

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.

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?

Through 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.