Monthly Archives: September 2009

Science Wednesday: Risk Assessment In Every Day Life

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.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Got a video camera? Enter our contest!

As Christina Wadlington discussed back in August, we’re looking for videos teaching people about preventing lead poisoning.

The deadline is October 1, so get hopping!

Here are a few links to get you going:

Go grab a camera, unleash your creativity, and enter!

Jeffrey Levy is EPA’s Director of Web Communications.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Alpha, Beta, Gamma, OH MY! Challenges In The Radiation World

Although I have been surrounded by radiation my entire life, it wasn’t until 2003, when I began my doctorate work, that I entered the “radiation world.” Since that time I have learned so much about radiation and realize there is much more to learn. I have also come to recognize a variety of challenges that exist in the radiation world.

Despite being surrounded by naturally occurring radiation, very few people really understand it. This is just one challenge we, radiation professionals, need to address. Other challenges include understanding the unique behavior of each radioactive element (or radionuclide), the various areas of study within the field of radiation, the multiple uses of radiation in our society, the fear of radiation, and the decreasing workforce knowledgeable in the field of radiation.

Some areas of radiation work include understanding: the fate and transport of radionuclides (how they behave in water, soil, air); biological effects of radiation (effects on human health); how to prepare, prevent and respond to radiation emergencies; how to set protective regulatory limits; and how to use radiation as a benefit to society (medicine, energy…).

Each radionuclide exhibits unique biological, chemical, and physical properties. What does this mean? It means that different radionuclides behave differently in various media (soil, water, air) as well as in the human body. Radionuclides also have unique radiological properties, such as the type of radioactive decay (alpha, beta, gamma) or the length of time they will be around before being transformed into a stable (non radioactive) element. Fully understanding the world of radiation means understanding all of these things for multiple radionuclides; what a challenge!

Another challenge is addressing the fear of radiation while improving the public’s general knowledge of radiation. EPA is meeting this challenge through various radiation education products like RadTown USA.

It will be increasingly difficult to increase public knowledge without the right staff. The number of radiation professionals is not growing at the rate it should be. More students need to be encouraged to not only study STEM (science, technology, engineering, and math) areas, but also to specialize in one of the diverse fields of radiation.

As an Engineer at EPA, I look forward to meeting all of these challenges head on, learning more about radiation and working to get the word out about radiation, educating people about the role of radiation in their daily lives, and encouraging them to join the “radiation world.”

About the Author: Dr. Angelique D. Diaz joined EPA in June of 2008 after completing her Ph.D., where she studied the behavior of plutonium in the environment. Dr. Diaz is an Environmental Engineer working at EPA’s Region 8 office in Denver, CO, where she works on a variety of radiological-related activities, including regulating radon emissions from uranium mines and mills.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Question of the Week: What are you doing to reduce pollution?

Next year is the 20th anniversary of the Pollution Prevention Act, which made P2 the option of first choice for reducing air emissions, water discharges, preventing health and environmental exposures to harmful substances, and the generation of wastes.  Pollution Prevention Week is September 21-29.

What are you doing to reduce pollution?

Each week we ask a question related to the environment. Please let us know your thoughts as comments. Feel free to respond to earlier comments or post new ideas. Previous questions.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Pregunta de la Semana: ¿Qué está haciendo para reducir la contaminación?

El año próximo se celebra el 20mo aniversario de la Ley de Prevención de Contaminación que establece la prevención de la contaminación (P2, por sus siglas en inglés) como la primera opción para reducir las emisiones de aire, descargas al agua, prevención de las exposiciónes a sustancias dañinas y la generación de desperdicios. La Semana de Prevención de Contaminación es del 21 al 29 de septiembre.

¿Qué está haciendo para reducir la contaminación?

Cada semana hacemos una pregunta relacionada al medio ambiente. Por favor comparta con nosotros sus pensamientos y comentarios. Siéntase en libertad de responder a comentarios anteriores o plantear nuevas ideas. Preguntas previas.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Food Consumption as a Means of Environmental Stewardship

Have you had a friend or colleague describe himself as a “locavore” and not grasped what was meant? According to Merriam-Webster’s On-line Dictionary, a locavore is someone “who eats locally grown food whenever possible.”

Recently, I visited the Red Stick Farmers Market, one of the weekly agricultural sales in Baton Rouge organized by Big River Economic & Agricultural Development Alliance (www.breada.org). Local growers and food preparers bring vegetables, meats, grains, pastries, honeys, jams, jellies, eggs & cheeses as well as herbs and flowering plants to the open air market near the Louisiana Department of Environmental Quality’s office in downtown Baton Rouge. The market is held every Saturday morning at this location and at other designated spots on other days of the week.

There are a number of reasons for consumers to support and frequent these local markets. You are obtaining fresh foods for your family that in most cases were harvested and prepared within days of your purchases. By operating on a smaller scale than corporate operations, a number of the farms are “organic” or use less chemicals since the crops do not need to be shipped great distances and be subjected to multiple handlings and pests. Many of the farmers are small business operations in the community so your food dollars stay in the local area.

According to the Intergovernmental Panel on Climate Change, the organization created by the United Nations Environmental Programme and the World Meteorological Organization to assess climate change, 13.5 of greenhouse gas emissions are attributed to agricultural practices, not including transportation and shipping. By taking part in the locally grown food market that does not need extended transportation from across the country or from around the world, you are reducing your family’s carbon footprint.

image of farmers market stand displaying potatoes and greens with people shoppingAnd as I overheard two shoppers say, “The fruits and vegetables just test better than what comes from large scale farms.”

So next week, line up with your neighbors and support the environment by buying locally grown farm products.

About the author: Rob Lawrence joined EPA in 1990 and is Senior Policy Advisor on Energy Issues in the Dallas, TX regional office. As an economist, he works to insure that both supply and demand components are addressed as the Region develops its Clean Energy and Climate Change Strategy.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Starfish Wonders in Alaska

image od two orange starfish in clear waterStarfish are mysterious creatures. Some people and articles I have read say they should be called sea stars because of their shape and their lack of relationship to fish. I had never taken an interest in them until recently when I visited Alaska and kayaked on the Tatoosh Islands. The Tatoosh are located north of Ketchikan and are part of the Tongass National Forest,  U.S largest national forest.  While kayaking along the coast, I spotted an incredible array of these colorful creatures. Bright orange and pale lavender, spiny and fat, each one more different than the other, they nestled into the dark rocks along the shore.

The starfish on Alaska are extremely different from the giant ones I have seen before on Vieques, Puerto Rico. While their Caribbean relatives are larger and rounder, the ones in the north Pacific cold waters are smaller in size. After kayaking around the Tatoosh, I began my research on these particular sea habitants. Starfish are echinoderms or marine invertebrates with a five-radial symmetry that radiates from a central disc, hence their resemblance to a star. They move by using small water-filled sacs that protrude from their body. This hydraulic vascular system, aside from helping them move, aids them with feeding. Speaking of which, they have two stomachs: one for engulfing their prey and the other one for digestion!  They have a microscopic eye at the end of each arm which helps them move and distinguish between light and dark. While they have a complex nervous system, they lack a centralized brain. I was also very surprised to learn that they are able to regenerate lost arms and that they can travel considerable distances and migrate to breed and search for food.

Starfish have been around five hundred million years and there are around 1,800 species. This region of the North Pacific is among three areas of the world that yields the greatest variety of these echinoderms. Starfish are vital to marine ecosystems because they are calcifiers. Marine calcifiers play important roles in the food chains of nearly all oceanic ecosystems, help regulate ocean chemistry, and are an important source of biodiversity and productivity.

In order to celebrate my new found love for these unique and mysterious creatures, I acquired during my trip a beautiful ring with a silver starfish adhered to a blue stone resembling the ocean.

About the author: Brenda Reyes Tomassini joined EPA in 2002. She is a public affairs specialist in the San Juan, Puerto Rico office and also handles community relations for the Caribbean Environmental Protection Division.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Las estrellas de mar del Pacífico Norte

image of two orange starfish in clear water Las estrellas de mar son criaturas misteriosas. De acuerdo a algunas personas y artículos que he leído las estrellas de mar no están relacionadas con los peces. Nunca me interesaron hasta recientemente cuando visité Alaska y navegué en kayak por las islas Tatoosh en el Parque Nacional Tongass y ví una gran multitud de estas.  Anaranjadas y violetas, grandes y puntiagudas, cada una más diferente de la otra, todas adheridas a las rocas de la orilla.

Las estrellas de mar de Alaska son extremadamente diferentes a sus parientes del Caribe. En Vieques, Puerto Rico las estrellas de mar son mucho más grandes y redondas que las de la costa del Pacífico Norte. Luego de navegar en las frías aguas de Tatoosh me di a la tarea de buscar más información sobre estos curiosos animales. Las estrellas de mar son equinodermos, o sea, animales marinos invertebrados. Su figura consta de un disco central del cual radian cinco extremidades es por esto que parecen una estrella. Estas se mueven utilizando un sistema vascular hidráulico–es por esto que tienen unos sacos protuberantes en sus extremidades–el cual también le ayuda con su alimentación. ¡Vale la pena señalar que tienen dos estómagos! Uno para atrapar su presa y el otro para digerirla. En sus extremidades cuentan con un ojo microscópico que les ayuda a moverse y a distinguir la luz y la oscuridad. Aunque tienen un sistema nervioso complejo y sofisticado, las estrellas de mar no cuentan con un cerebro centralizado. Me sorprendí al leer que pueden regenerar las extremidades perdidas y viajar largas distancias en busca de comida o para aparearse.

La región del Pacífico Norte es una de las tres áreas en el mundo que mayor variedad de estrellas de mar posee. Hay cerca de 1,800 especies y han estado en la tierra por los últimos quinientos millones de años. Las estrellas de mar son sumamente importantes para los ecosistemas marinos por que son calcificantes. Los calcificantes marinos juegan un rol importante en la cadena alimenticia de los ecosistemas oceánicos ya que ayudan a regular la química oceánica y son fuente de biodiversidad y productividad

Para celebrar mi nuevo apego a estas interesantes y misteriosas criaturas del mar adquirí una sortija con una estrella marina durante mi viaje.

Sobre la autor: Brenda Reyes Tomassini se unió a la EPA en el 2002. Labora como especialista de relaciones públicas en la oficina de EPA en San Juan, Puerto Rico donde también maneja asuntos comunitarios para la División de Protección Ambiental del Caribe.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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

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.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Setting National Priorities for Enforcement and Compliance Assurance

Are you interested in playing a role in setting priorities with EPA? Do you have an interest in the compliance and enforcement of environmental laws? I’d like to tell you about an exciting opportunity to share your feedback with EPA on the environmental problems that are most important to you.

EPA is in the process of selecting new priorities to focus our enforcement and compliance work in 2011-2013. As part of this process, we would like to collect a wide range of views from the public on the most important environmental problems that occur nationwide. It would also be helpful if you could share a little bit about the reasons why you think that a particular problem is significant from your perspective. For example, if you considered any particular pieces of information, such as news articles, or reports about environmental issues, please send us information about those sources of information as well.

Our decisions regarding future priorities will consider the following key questions:

  • Is the environmental problem happening nationwide or only in an isolated area?
  • Does the environmental problem offer an opportunity for EPA, rather than a state, to play a major role in environmental protection?
  • Does the environmental problem happen frequently because the source emitting the pollution is not following the requirements of environmental laws and regulations?

Here’s how to get started:

About the Author: Elizabeth Walsh joined the US Environmental Protection Agency in Washington, DC in 2001. She currently works on setting national priorities with EPA’s enforcement and compliance assurance program and analyzing environmental data to help EPA set long-term environmental goals.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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