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Organic
Carbon and the World around Us
DESCRIPTION:
In this episode, we talk about
organic carbon. The benefit of studying carbon extends to
many issues, including tracing mercury contamination or investigating
disinfection by-products in drinking water treatment. It is amazing what can be
discovered by monitoring the volume and flux of carbon through the environment.
Learn about the biogeochemistry of carbon from USGS
research chemists George Aiken and Brian Bergamaschi,
only in this episode of the USGS Oregon Science Podcast.
TAGS:
OrganicCarbon OrganicMatter
Dissolved Carbon Fluorescence DrinkingWater Mercury
Toxics Pollutants FDOM Biogeochemistry
LOCATION: Rhododendron Garden, Portland,
Oregon
DATE
FILMED: Principle
photography May 2, 2012
PRODUCER:
Steven Sobieszczyk
VIDEOGRAPHER:
Steven Sobieszczyk, Doug Harned
VIDEOGRAPHER
EMAIL: ssobie@usgs.gov
VIDEOGRAPHER
ORGANIZATION: U.S.
Geological Survey
VIDEO
CREDITS: George
Aiken, Brian Bergamaschi
SOURCE:
(Web site) http://carbon.wr.usgs.gov/
(Web site) http://www.usgs.gov/mercury/
(Web site) http://toxics.usgs.gov/
(Web site) http://or.water.usgs.gov/podcasts
(Web site) http://or.water.usgs.gov/
Organic
Carbon and the World around Us
DESCRIPTION:
In
this episode, we talk about organic carbon. The benefit of studying carbon
extends to many issues, including tracing mercury
contamination or investigating disinfection by-products in drinking water
treatment. It is amazing what can be discovered by monitoring the volume and
flux of carbon through the environment. Learn about
the biogeochemistry of carbon from USGS research chemists George Aiken and
Brian Bergamaschi, only in this episode of the USGS
Oregon Science Podcast.
[Intro
Music begins: Violin, Sylvia, Classical One and Only]
OPENING CREDITS: “Carbon is a
unique element in the periodic table in that it forms bonds with itself.” “But
not all carbon is the same.” “Carbon, as an element, can form inorganic
materials, such as carbon dioxide.” “It also contributes to the diversity of
life.”
[Background
Music: Rubber Cement, Fresh Music Library, Acoustic Guitar Moods Vol. 2]
[NARRATION:
Steven Sobieszczyk] Although, not particularly
abundant in the Earth’s rocky crust, the element carbon does play a vital role in the presence and evolution of all
life on Earth. Starting with some of the smallest molecules, such as proteins
and amino acids, up through bacteria, plants, and animals – all life forms, and
therefore all organic matter, is made from carbon. It exists in environments
both on land and at the sea. It presents itself in the grass at our feet and in
the food that we eat. However, carbon seldom remains in one place very long. It
continuously breaks down and takes new forms as it is renewed through the process
of the carbon cycle.
[George
Aiken] So, when
we are studying dissolved organic matter, we’re a very narrow slice of the pie
on this path from carbon coming from CO2 to photosynthesis and
through subsequent utilization and degradation by other organisms down the line
back up to CO2. That’s the link between the organic carbon world we
know in soil and plants and the inorganic carbon world, which is the CO2
in the atmosphere.
[Brian
Bergamaschi] Well, so what do we do? We go out and we look at
carbon that is dissolved in aquatic systems in a whole bunch of different ways.
Sometimes we go out and grab a sample of water and take it back to the
laboratory and we might do simple characterizations, such as put it into a
spectrophotometer and look at how much light has attenuated as it passes
through the sample. Or we might look at the fluorescence properties of that
organic material. And that gives us some information about the constituents…the
chemicals that make up that aquatic carbon that is in the sample.
[Background
Music: Java Fly By, Fresh Music Library, Acoustic Atmospheres]
[NARRATION:
Steven Sobieszczyk] Organic carbon is highly reactive
with other substances and it is often tied up in a variety of reactions in
nature. For example, in aquatic environments this may include aiding the transport
of toxic materials or pollutants by binding with pesticides or other toxic
metals, such as mercury. It is this ability to bind with other compounds that can
facilitate the transport of these dangerous materials and can foster the uptake
of these toxic materials by other organisms.
[George
Aiken] In
particular, one of the major societal issues that we’re working on is the way
in which dissolved organic matter controls the biogeochemistry of mercury. And
mercury is a very interesting element in that in some of its forms it is a
powerful neurotoxin and so when it gets into the food web and gets into the
higher parts of the food web, such as game fish, we’re then susceptible if we
eat those fish, to accumulate mercury ourselves.
[NARRATION:
Steven Sobieszczyk] Besides mercury, another reaction
of organic carbon observed in aquatic environments relates to something most
people use every day, municipal supplies of drinking water.
[Brian
Bergamaschi] Drinking water treatment plants grab water from
lakes and rivers, and that has some of this dissolved organic carbon in it. And
then they use power techniques…chemical techniques…for disinfection. So, they
put in chemicals, such as chlorine, and the chlorine reacts with the dissolved
organic matter to form these chemical by-products, called disinfection by-products,
that are toxic and they’re regulated by the EPA in finished drinking water
because they are unsafe for human consumption above a certain level.
[Background
Music: Java Fly By, Fresh Music Library, Acoustic Atmospheres]
[NARRATION:
Steven Sobieszczyk] Knowing what forms in the water
is only part of the story. Being able to measure and monitor changes to the
environment is just as important.
[Brian
Bergamaschi] One of the coolest things about studying carbon…organic
carbon…in lakes and rivers and the ocean is that carbon tells a story. It tells
a story about where its come
from, what’s happened to it along the way, and what its likely environmental
fate is. And what’s really neat lately is we’ve been developing sensors that
you can go out and stick in the water and you can measure the variations in the
amount of that stuff that’s there but also the quality of that stuff. And this
is a whole brave new world in organic geochemistry because we can figure out
how our watersheds are functioning and how the river ecology is functioning
on-the-fly, in real-time and we can broadcast that on the web.
[Background
Music: Rubber Cement, Fresh Music Library, Acoustic Guitar Moods Vol. 2]
[NARRATION:
Steven Sobieszczyk] The insights that USGS research
chemists gain from carbon help guide policies that affect the health and safety
for people and the world around us.
[George
Aiken] We all,
in our daily lives, understand maybe not in a direct way, but the example I
like to use is that if you head off to buy coffee in the morning and you’re in
desperate need of caffeine, and you get a cup of decaf, its one molecule that
makes the difference between you falling asleep at your desk or being wide
awake. So, our job is to understand the reactivity of different individual
molecules and how they are controlling critical processes on the planet.
[Background
Music: Violin, Sylvia, Classical One and Only]
[NARRATION:
Steven Sobieszczyk] Want to learn more? Additional
information on how the USGS studies organic carbon, as well as its interaction
with other compounds and pollutants can be found online. If you are interested
in other USGS research you can follow the USGS daily on Twitter, Facebook, or
YouTube.
[DISCLAIMER:
Heather Bragg] This
podcast is a product of the U.S. Geological Survey, Department of the Interior.