Page 45 - Environment: The Science Behind the Stories

THE SCIENCE BEHIND THE STORY

Tracking Fukushima’s Scientists equate the input of radio- Japan and working their way in to 32
Nuclear Legacy isotopes into waters to “pouring dye into km (20 mi) offshore. At 30 sites along
the ocean.” By knowing the half-lives of
the cruise route, the scientists tested
relevant radioisotopes and their daughter the air and water for radioactivity, col-
isotopes and by tracking their quantities lected water samples to measure levels
across bodies of water, scientists can of several radioisotopes (Figure 1), and
study large-scale circulation patterns in tested plankton and other free-swimming
inland seas and the ocean. Quick action organisms to determine the extent of
was needed, so Buesseler scrambled radioisotope uptake by organisms.
to assemble a team of scientists and Buesseler’s group found water
secure resources to mount an expedi- radiation levels of more than 100,000
3
tion to sample the waters offshore from becquerels per cubic meter (Bq/m ; a
Fukushima before the radioisotopes becquerel is a unit of measurement for
dispersed throughout the Pacific. radioactivity) in early April, up from a pre-
Thanks to a $3.7-million award from accident level of about 1.5 becquerels
the Gordon and Betty Moore Foundation, per cubic meter. These post-accident
Buesseler and his colleagues were able radiation levels were about 100 times
to charter the research vessel Ka’imikai- greater than those found in the Black
o-Kanaloa from the University of Hawaii Sea after the Chernobyl incident (Figure 2).
and zigzag their way through the waters So while the release of radioisotopes
of the north Pacific in June 2011—start- from Chernobyl was roughly five times
ing 640 km (400 mi) off the coast of larger than that from Fukushima, the
dr. Ken buesseler, Woods hole
oceanographic institution

When Dr. Ken Buesseler, a senior
scientist at the Woods Hole Oceano-
graphic Institution in Massachusetts,
observed the events unfolding in
northeastern Japan in 2011, he saw
an opportunity to use his expertise to
determine the movements and fate
of the radioisotopes released into
the Pacific Ocean from the crippled
Fukushima Daiichi nuclear power plant.
Dr. Buesseler had done this before
when he used radioisotopes released
from the Chernobyl nuclear accident
(Chapter 20) in 1986 as tracers to study
the poorly-understood currents in the Figure 1 an international team of scientists tracked the fate of radioactive
nearby Black Sea. material released into the ocean from the Fukushima nuclear power plant.

bonds due to their differing electrical charges. Such associa- of constituents such as nitrogen, oxygen, water vapor, carbon
tions are called ionic compounds, or salts. Table salt (NaCl) dioxide, methane (CH ), and ozone (O ). Ocean water, plant
3
4
contains ionic bonds between positively charged sodium sap, petroleum, and metal alloys such as brass are all solutions.
ions (Na ), each of which donates an electron, and negatively
+
charged chloride ions (Cl ), each of which receives an electron. Water’s chemistry facilitates life
–
Elements, molecules, and compounds can also come
together in mixtures without chemically bonding or reacting. Water has unique properties that give it an amazing capacity
Homogeneous mixtures of substances are called solutions, a to support life. Water’s ability to form loose connections of
term most often applied to liquids, but also applicable to some hydrogen bonds gives it several properties that help to support
44 gases and solids. Air in the atmosphere is a solution formed life and stabilize Earth’s climate:

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